tag:blogger.com,1999:blog-230212552012-01-27T22:09:51.144+01:00Internetworking perspectives by Ivan PepelnjakIvan Pepelnjakhttp://www.blogger.com/profile/13457151406311272386noreply@blogger.comBlogger1515125CiscoIosHintsAndTrickshttp://feedburner.google.comSubscribe with My Yahoo!Subscribe with My AOLSubscribe with BloglinesSubscribe with GoogleSubscribe with PageflakesSubscribe with Live.comAdd to Any Feed Readertag:blogger.com,1999:blog-23021255.post-39019920967899997752012-01-27T11:53:00.000+01:002012-01-27T11:53:01.367+01:00<p>One of my users was complaining about error messages he's getting from Google Wallet when trying to buy the yearly subscription. He wrote "<em>When I try to login with my Google credentials I get some kind of error page where I can't do anything unless I supply them with scan copies of an ID</em>." Is anyone else experiencing problems? Thank you!</p><div class="blogger-post-footer"><img width='1' height='1' src='https://blogger.googleusercontent.com/tracker/23021255-3901992096789999775?l=blog.ioshints.info' alt='' /></div><div class="feedflare"> <a href="http://feeds.feedburner.com/~ff/CiscoIosHintsAndTricks?a=CDTY3h4oMzs:5-R54W-gqsg:yIl2AUoC8zA"><img src="http://feeds.feedburner.com/~ff/CiscoIosHintsAndTricks?d=yIl2AUoC8zA" border="0"></img></a> <a href="http://feeds.feedburner.com/~ff/CiscoIosHintsAndTricks?a=CDTY3h4oMzs:5-R54W-gqsg:qj6IDK7rITs"><img src="http://feeds.feedburner.com/~ff/CiscoIosHintsAndTricks?d=qj6IDK7rITs" border="0"></img></a> <a href="http://feeds.feedburner.com/~ff/CiscoIosHintsAndTricks?a=CDTY3h4oMzs:5-R54W-gqsg:I9og5sOYxJI"><img src="http://feeds.feedburner.com/~ff/CiscoIosHintsAndTricks?d=I9og5sOYxJI" border="0"></img></a> <a href="http://feeds.feedburner.com/~ff/CiscoIosHintsAndTricks?a=CDTY3h4oMzs:5-R54W-gqsg:F7zBnMyn0Lo"><img src="http://feeds.feedburner.com/~ff/CiscoIosHintsAndTricks?i=CDTY3h4oMzs:5-R54W-gqsg:F7zBnMyn0Lo" border="0"></img></a> <a href="http://feeds.feedburner.com/~ff/CiscoIosHintsAndTricks?a=CDTY3h4oMzs:5-R54W-gqsg:V_sGLiPBpWU"><img src="http://feeds.feedburner.com/~ff/CiscoIosHintsAndTricks?i=CDTY3h4oMzs:5-R54W-gqsg:V_sGLiPBpWU" border="0"></img></a> <a href="http://feeds.feedburner.com/~ff/CiscoIosHintsAndTricks?a=CDTY3h4oMzs:5-R54W-gqsg:4cEx4HpKnUU"><img src="http://feeds.feedburner.com/~ff/CiscoIosHintsAndTricks?i=CDTY3h4oMzs:5-R54W-gqsg:4cEx4HpKnUU" border="0"></img></a> </div><img src="http://feeds.feedburner.com/~r/CiscoIosHintsAndTricks/~4/CDTY3h4oMzs" height="1" width="1"/>Ivan Pepelnjakhttp://www.blogger.com/profile/13457151406311272386noreply@blogger.com0http://blog.ioshints.info/2012/01/is-anyone-having-problems-with-google.htmltag:blogger.com,1999:blog-23021255.post-90264387378895847842012-01-27T07:18:00.000+01:002012-01-27T07:31:16.424+01:00<p>Did you rush to try OSPF Loop Free Alternate on a Cisco 7200 after reading my <a href="http://blog.ioshints.info/2012/01/loop-free-alternate-ospf-meets-eigrp.html">LFA blog post</a> ... and disappointedly discovered that it only works on Cisco 7600? The reason is simple: while LFA does add feasible-successor-like behavior to OSPF, its primary mission is to improve RIB-to-FIB convergence time.</p><a href="http://blog.ioshints.info/2012/01/prefix-independent-convergence-pic.html#more">Read more ...</a><div class="blogger-post-footer"><img width='1' height='1' src='https://blogger.googleusercontent.com/tracker/23021255-9026438737889584784?l=blog.ioshints.info' alt='' /></div><div class="feedflare"> <a href="http://feeds.feedburner.com/~ff/CiscoIosHintsAndTricks?a=KfcPDCPigPU:vh9b83mZtrk:yIl2AUoC8zA"><img src="http://feeds.feedburner.com/~ff/CiscoIosHintsAndTricks?d=yIl2AUoC8zA" border="0"></img></a> <a href="http://feeds.feedburner.com/~ff/CiscoIosHintsAndTricks?a=KfcPDCPigPU:vh9b83mZtrk:qj6IDK7rITs"><img src="http://feeds.feedburner.com/~ff/CiscoIosHintsAndTricks?d=qj6IDK7rITs" border="0"></img></a> <a href="http://feeds.feedburner.com/~ff/CiscoIosHintsAndTricks?a=KfcPDCPigPU:vh9b83mZtrk:I9og5sOYxJI"><img src="http://feeds.feedburner.com/~ff/CiscoIosHintsAndTricks?d=I9og5sOYxJI" border="0"></img></a> <a href="http://feeds.feedburner.com/~ff/CiscoIosHintsAndTricks?a=KfcPDCPigPU:vh9b83mZtrk:F7zBnMyn0Lo"><img src="http://feeds.feedburner.com/~ff/CiscoIosHintsAndTricks?i=KfcPDCPigPU:vh9b83mZtrk:F7zBnMyn0Lo" border="0"></img></a> <a href="http://feeds.feedburner.com/~ff/CiscoIosHintsAndTricks?a=KfcPDCPigPU:vh9b83mZtrk:V_sGLiPBpWU"><img src="http://feeds.feedburner.com/~ff/CiscoIosHintsAndTricks?i=KfcPDCPigPU:vh9b83mZtrk:V_sGLiPBpWU" border="0"></img></a> <a href="http://feeds.feedburner.com/~ff/CiscoIosHintsAndTricks?a=KfcPDCPigPU:vh9b83mZtrk:4cEx4HpKnUU"><img src="http://feeds.feedburner.com/~ff/CiscoIosHintsAndTricks?i=KfcPDCPigPU:vh9b83mZtrk:4cEx4HpKnUU" border="0"></img></a> </div><img src="http://feeds.feedburner.com/~r/CiscoIosHintsAndTricks/~4/KfcPDCPigPU" height="1" width="1"/>Ivan Pepelnjakhttp://www.blogger.com/profile/13457151406311272386noreply@blogger.com6http://blog.ioshints.info/2012/01/prefix-independent-convergence-pic.htmltag:blogger.com,1999:blog-23021255.post-67945697970065935112012-01-26T06:18:00.000+01:002012-01-26T06:18:00.045+01:00<p>Assume we have a simple triangular network:</p><div class="separator" style="clear: both; text-align: center;"><a href="http://4.bp.blogspot.com/-CcuRDmL3w8A/Tx1sGYsLSBI/AAAAAAAAEsk/u3ii9ASsKuw/s1600/LFA_Topology.png" imageanchor="1" style="margin-left:1em; margin-right:1em"><img border="0" height="134" width="303" src="http://4.bp.blogspot.com/-CcuRDmL3w8A/Tx1sGYsLSBI/AAAAAAAAEsk/u3ii9ASsKuw/s400/LFA_Topology.png"></a></div><p>Now imagine the A-to-C link fails. How will OSPF react to the link failure as compared to EIGRP? Which one will converge faster? Try to answer the questions before pressing the <em>Read more </em>link ;)</p><a href="http://blog.ioshints.info/2012/01/loop-free-alternate-ospf-meets-eigrp.html#more">Read more ...</a><div class="blogger-post-footer"><img width='1' height='1' src='https://blogger.googleusercontent.com/tracker/23021255-6794569797006593511?l=blog.ioshints.info' alt='' /></div><div class="feedflare"> <a href="http://feeds.feedburner.com/~ff/CiscoIosHintsAndTricks?a=z3IcbF5Y1Cc:N8FVrPPg87Q:yIl2AUoC8zA"><img src="http://feeds.feedburner.com/~ff/CiscoIosHintsAndTricks?d=yIl2AUoC8zA" border="0"></img></a> <a href="http://feeds.feedburner.com/~ff/CiscoIosHintsAndTricks?a=z3IcbF5Y1Cc:N8FVrPPg87Q:qj6IDK7rITs"><img src="http://feeds.feedburner.com/~ff/CiscoIosHintsAndTricks?d=qj6IDK7rITs" border="0"></img></a> <a href="http://feeds.feedburner.com/~ff/CiscoIosHintsAndTricks?a=z3IcbF5Y1Cc:N8FVrPPg87Q:I9og5sOYxJI"><img src="http://feeds.feedburner.com/~ff/CiscoIosHintsAndTricks?d=I9og5sOYxJI" border="0"></img></a> <a href="http://feeds.feedburner.com/~ff/CiscoIosHintsAndTricks?a=z3IcbF5Y1Cc:N8FVrPPg87Q:F7zBnMyn0Lo"><img src="http://feeds.feedburner.com/~ff/CiscoIosHintsAndTricks?i=z3IcbF5Y1Cc:N8FVrPPg87Q:F7zBnMyn0Lo" border="0"></img></a> <a href="http://feeds.feedburner.com/~ff/CiscoIosHintsAndTricks?a=z3IcbF5Y1Cc:N8FVrPPg87Q:V_sGLiPBpWU"><img src="http://feeds.feedburner.com/~ff/CiscoIosHintsAndTricks?i=z3IcbF5Y1Cc:N8FVrPPg87Q:V_sGLiPBpWU" border="0"></img></a> <a href="http://feeds.feedburner.com/~ff/CiscoIosHintsAndTricks?a=z3IcbF5Y1Cc:N8FVrPPg87Q:4cEx4HpKnUU"><img src="http://feeds.feedburner.com/~ff/CiscoIosHintsAndTricks?i=z3IcbF5Y1Cc:N8FVrPPg87Q:4cEx4HpKnUU" border="0"></img></a> </div><img src="http://feeds.feedburner.com/~r/CiscoIosHintsAndTricks/~4/z3IcbF5Y1Cc" height="1" width="1"/>Ivan Pepelnjakhttp://www.blogger.com/profile/13457151406311272386noreply@blogger.com17http://blog.ioshints.info/2012/01/loop-free-alternate-ospf-meets-eigrp.htmltag:blogger.com,1999:blog-23021255.post-61771935756988476622012-01-25T06:28:00.000+01:002012-01-25T06:28:00.189+01:00<p>Scott Lowe asked a very good question in his <a href="http://blog.scottlowe.org/2012/01/20/technology-short-take-20/">Technology Short Take #20</a>:</p><blockquote class="cite">VXLAN uses UDP for its encapsulation. What about dropped packets, lack of sequencing, etc., that is possible with UDP? What impact is that going to have on the “inner protocol” that’s wrapped inside the VXLAN UDP packets? Or is this not an issue in modern networks any longer?</blockquote><p><strong>Short answer</strong>: No problem.</p><a href="http://blog.ioshints.info/2012/01/vxlan-runs-over-udp-does-it-matter.html#more">Read more ...</a><div class="blogger-post-footer"><img width='1' height='1' src='https://blogger.googleusercontent.com/tracker/23021255-6177193575698847662?l=blog.ioshints.info' alt='' /></div><div class="feedflare"> <a href="http://feeds.feedburner.com/~ff/CiscoIosHintsAndTricks?a=FJj11w0VArE:h6VGMXFs4cg:yIl2AUoC8zA"><img src="http://feeds.feedburner.com/~ff/CiscoIosHintsAndTricks?d=yIl2AUoC8zA" border="0"></img></a> <a href="http://feeds.feedburner.com/~ff/CiscoIosHintsAndTricks?a=FJj11w0VArE:h6VGMXFs4cg:qj6IDK7rITs"><img src="http://feeds.feedburner.com/~ff/CiscoIosHintsAndTricks?d=qj6IDK7rITs" border="0"></img></a> <a href="http://feeds.feedburner.com/~ff/CiscoIosHintsAndTricks?a=FJj11w0VArE:h6VGMXFs4cg:I9og5sOYxJI"><img src="http://feeds.feedburner.com/~ff/CiscoIosHintsAndTricks?d=I9og5sOYxJI" border="0"></img></a> <a href="http://feeds.feedburner.com/~ff/CiscoIosHintsAndTricks?a=FJj11w0VArE:h6VGMXFs4cg:F7zBnMyn0Lo"><img src="http://feeds.feedburner.com/~ff/CiscoIosHintsAndTricks?i=FJj11w0VArE:h6VGMXFs4cg:F7zBnMyn0Lo" border="0"></img></a> <a href="http://feeds.feedburner.com/~ff/CiscoIosHintsAndTricks?a=FJj11w0VArE:h6VGMXFs4cg:V_sGLiPBpWU"><img src="http://feeds.feedburner.com/~ff/CiscoIosHintsAndTricks?i=FJj11w0VArE:h6VGMXFs4cg:V_sGLiPBpWU" border="0"></img></a> <a href="http://feeds.feedburner.com/~ff/CiscoIosHintsAndTricks?a=FJj11w0VArE:h6VGMXFs4cg:4cEx4HpKnUU"><img src="http://feeds.feedburner.com/~ff/CiscoIosHintsAndTricks?i=FJj11w0VArE:h6VGMXFs4cg:4cEx4HpKnUU" border="0"></img></a> </div><img src="http://feeds.feedburner.com/~r/CiscoIosHintsAndTricks/~4/FJj11w0VArE" height="1" width="1"/>Ivan Pepelnjakhttp://www.blogger.com/profile/13457151406311272386noreply@blogger.com5http://blog.ioshints.info/2012/01/vxlan-runs-over-udp-does-it-matter.htmltag:blogger.com,1999:blog-23021255.post-66301997088291652622012-01-24T07:23:00.000+01:002012-01-24T07:23:00.704+01:00<p>In the <a href="http://blog.ioshints.info/2012/01/redundant-dmvpn-designs-part-1-basics.html"><em>Redundant DMVPN Design, Part 1</em></a> I described the options you have when you want to connect non-redundant spokes to more than one hub. In this article, we’ll go a step further and design hub and spoke sites with multiple uplinks.</p><h4>Public IP addressing</h4><p><strong>Fact:</strong> DMVPN tunnel endpoints have to use public IP addresses or the hub/spoke routers wouldn’t be able to send GRE/IPsec packets across the public backbone.</p><a href="http://blog.ioshints.info/2012/01/redundant-dmvpn-designs-part-2-multiple.html#more">Read more ...</a><div class="blogger-post-footer"><img width='1' height='1' src='https://blogger.googleusercontent.com/tracker/23021255-6630199708829165262?l=blog.ioshints.info' alt='' /></div><div class="feedflare"> <a href="http://feeds.feedburner.com/~ff/CiscoIosHintsAndTricks?a=HoudrMhZQTA:c4bqw1IlPLs:yIl2AUoC8zA"><img src="http://feeds.feedburner.com/~ff/CiscoIosHintsAndTricks?d=yIl2AUoC8zA" border="0"></img></a> <a href="http://feeds.feedburner.com/~ff/CiscoIosHintsAndTricks?a=HoudrMhZQTA:c4bqw1IlPLs:qj6IDK7rITs"><img src="http://feeds.feedburner.com/~ff/CiscoIosHintsAndTricks?d=qj6IDK7rITs" border="0"></img></a> <a href="http://feeds.feedburner.com/~ff/CiscoIosHintsAndTricks?a=HoudrMhZQTA:c4bqw1IlPLs:I9og5sOYxJI"><img src="http://feeds.feedburner.com/~ff/CiscoIosHintsAndTricks?d=I9og5sOYxJI" border="0"></img></a> <a href="http://feeds.feedburner.com/~ff/CiscoIosHintsAndTricks?a=HoudrMhZQTA:c4bqw1IlPLs:F7zBnMyn0Lo"><img src="http://feeds.feedburner.com/~ff/CiscoIosHintsAndTricks?i=HoudrMhZQTA:c4bqw1IlPLs:F7zBnMyn0Lo" border="0"></img></a> <a href="http://feeds.feedburner.com/~ff/CiscoIosHintsAndTricks?a=HoudrMhZQTA:c4bqw1IlPLs:V_sGLiPBpWU"><img src="http://feeds.feedburner.com/~ff/CiscoIosHintsAndTricks?i=HoudrMhZQTA:c4bqw1IlPLs:V_sGLiPBpWU" border="0"></img></a> <a href="http://feeds.feedburner.com/~ff/CiscoIosHintsAndTricks?a=HoudrMhZQTA:c4bqw1IlPLs:4cEx4HpKnUU"><img src="http://feeds.feedburner.com/~ff/CiscoIosHintsAndTricks?i=HoudrMhZQTA:c4bqw1IlPLs:4cEx4HpKnUU" border="0"></img></a> </div><img src="http://feeds.feedburner.com/~r/CiscoIosHintsAndTricks/~4/HoudrMhZQTA" height="1" width="1"/>Ivan Pepelnjakhttp://www.blogger.com/profile/13457151406311272386noreply@blogger.com4http://blog.ioshints.info/2012/01/redundant-dmvpn-designs-part-2-multiple.htmltag:blogger.com,1999:blog-23021255.post-82404153209691573662012-01-23T06:53:00.000+01:002012-01-23T06:53:00.708+01:00<p>One of my readers couldn’t figure out which IPv6 webinar to buy. He wrote:</p><blockquote class="cite">I bought your <a href="http://www.ipspace.net/Service_Provider_IPv6_Introduction">Service Provider IPv6 Introduction</a> webinar. I’m also interested in <a href="http://www.ipspace.net/Building_IPv6_Service_Provider_Core">Building IPv6 Service Provider Core</a> and <a href="http://www.ipspace.net/Building_Large_IPv6_Access_Networks">Building Large IPv6 Access Networks</a>. I realized that the second training is not released yet and it says that it&#39;s an update session for the first training, so do I need to buy both? I would like to download all the material related to the trainings so I would watch them whenever I need.</blockquote><p>It seems I did overcomplicate a few things, so I’ll try to clear up the confusion I created.</p><a href="http://blog.ioshints.info/2012/01/clearing-up-ipv6-webinar-confusion.html#more">Read more ...</a><div class="blogger-post-footer"><img width='1' height='1' src='https://blogger.googleusercontent.com/tracker/23021255-8240415320969157366?l=blog.ioshints.info' alt='' /></div><div class="feedflare"> <a href="http://feeds.feedburner.com/~ff/CiscoIosHintsAndTricks?a=Kg07Vx6Dacs:bofCuav5p3Q:yIl2AUoC8zA"><img src="http://feeds.feedburner.com/~ff/CiscoIosHintsAndTricks?d=yIl2AUoC8zA" border="0"></img></a> <a href="http://feeds.feedburner.com/~ff/CiscoIosHintsAndTricks?a=Kg07Vx6Dacs:bofCuav5p3Q:qj6IDK7rITs"><img src="http://feeds.feedburner.com/~ff/CiscoIosHintsAndTricks?d=qj6IDK7rITs" border="0"></img></a> <a href="http://feeds.feedburner.com/~ff/CiscoIosHintsAndTricks?a=Kg07Vx6Dacs:bofCuav5p3Q:I9og5sOYxJI"><img src="http://feeds.feedburner.com/~ff/CiscoIosHintsAndTricks?d=I9og5sOYxJI" border="0"></img></a> <a href="http://feeds.feedburner.com/~ff/CiscoIosHintsAndTricks?a=Kg07Vx6Dacs:bofCuav5p3Q:F7zBnMyn0Lo"><img src="http://feeds.feedburner.com/~ff/CiscoIosHintsAndTricks?i=Kg07Vx6Dacs:bofCuav5p3Q:F7zBnMyn0Lo" border="0"></img></a> <a href="http://feeds.feedburner.com/~ff/CiscoIosHintsAndTricks?a=Kg07Vx6Dacs:bofCuav5p3Q:V_sGLiPBpWU"><img src="http://feeds.feedburner.com/~ff/CiscoIosHintsAndTricks?i=Kg07Vx6Dacs:bofCuav5p3Q:V_sGLiPBpWU" border="0"></img></a> <a href="http://feeds.feedburner.com/~ff/CiscoIosHintsAndTricks?a=Kg07Vx6Dacs:bofCuav5p3Q:4cEx4HpKnUU"><img src="http://feeds.feedburner.com/~ff/CiscoIosHintsAndTricks?i=Kg07Vx6Dacs:bofCuav5p3Q:4cEx4HpKnUU" border="0"></img></a> </div><img src="http://feeds.feedburner.com/~r/CiscoIosHintsAndTricks/~4/Kg07Vx6Dacs" height="1" width="1"/>Ivan Pepelnjakhttp://www.blogger.com/profile/13457151406311272386noreply@blogger.com0http://blog.ioshints.info/2012/01/clearing-up-ipv6-webinar-confusion.htmltag:blogger.com,1999:blog-23021255.post-39237922566961115462012-01-21T20:08:00.000+01:002012-01-22T10:56:12.476+01:00<p>According to Google Analytics these were the most popular posts I wrote in December 2011:</p><ul class="ListParagraph"><li><a href="http://blog.ioshints.info/2011/12/is-nat-security-feature.html">Is NAT a security feature?</a></li><li><a href="http://blog.ioshints.info/2011/12/decouple-virtual-networking-from.html">Decouple virtual networking from the physical world</a></li><li><a href="http://blog.ioshints.info/2011/12/large-scale-l2-dci-true-story.html">Large-scale L2 DCI: a true story</a></li><li><a href="http://blog.ioshints.info/2011/12/we-just-might-need-nat66.html">We just might need NAT66</a></li><li><a href="http://blog.ioshints.info/2011/12/vmware-vswitch-baseline-of-simplicity.html">VMware vSwitch – the baseline of simplicity</a></li><li><a href="http://blog.ioshints.info/2011/12/junos-day-one-mpls-behind-scenes.html">Junos Day One: MPLS Behind The Scenes</a></li><li><a href="http://blog.ioshints.info/2011/12/vxlan-ip-multicast-openflow-and-control.html">VXLAN, IP multicast, OpenFlow and control planes</a></li><li><a href="http://blog.ioshints.info/2011/12/which-virtual-networking-technology.html">Which virtual networking technology should I use?</a></li><li><a href="http://blog.ioshints.info/2011/12/nexus-1000v-and-vmotion.html">Nexus 1000V and vMotion</a></li><li><a href="http://blog.ioshints.info/2011/12/ipv6-multihoming-without-nat-problem.html">IPv6 multihoming without NAT: the problem</a></li><li><a href="http://blog.ioshints.info/2011/12/vm-aware-networking-improves-iaas-cloud.html">VM-aware Networking Improves IaaS Cloud Scalability</a></li></ul><div class="blogger-post-footer"><img width='1' height='1' src='https://blogger.googleusercontent.com/tracker/23021255-3923792256696111546?l=blog.ioshints.info' alt='' /></div><div class="feedflare"> <a href="http://feeds.feedburner.com/~ff/CiscoIosHintsAndTricks?a=ZkV7qKHIl7Y:RX3EyTxqzjg:yIl2AUoC8zA"><img src="http://feeds.feedburner.com/~ff/CiscoIosHintsAndTricks?d=yIl2AUoC8zA" border="0"></img></a> <a href="http://feeds.feedburner.com/~ff/CiscoIosHintsAndTricks?a=ZkV7qKHIl7Y:RX3EyTxqzjg:qj6IDK7rITs"><img src="http://feeds.feedburner.com/~ff/CiscoIosHintsAndTricks?d=qj6IDK7rITs" border="0"></img></a> <a href="http://feeds.feedburner.com/~ff/CiscoIosHintsAndTricks?a=ZkV7qKHIl7Y:RX3EyTxqzjg:I9og5sOYxJI"><img src="http://feeds.feedburner.com/~ff/CiscoIosHintsAndTricks?d=I9og5sOYxJI" border="0"></img></a> <a href="http://feeds.feedburner.com/~ff/CiscoIosHintsAndTricks?a=ZkV7qKHIl7Y:RX3EyTxqzjg:F7zBnMyn0Lo"><img src="http://feeds.feedburner.com/~ff/CiscoIosHintsAndTricks?i=ZkV7qKHIl7Y:RX3EyTxqzjg:F7zBnMyn0Lo" border="0"></img></a> <a href="http://feeds.feedburner.com/~ff/CiscoIosHintsAndTricks?a=ZkV7qKHIl7Y:RX3EyTxqzjg:V_sGLiPBpWU"><img src="http://feeds.feedburner.com/~ff/CiscoIosHintsAndTricks?i=ZkV7qKHIl7Y:RX3EyTxqzjg:V_sGLiPBpWU" border="0"></img></a> <a href="http://feeds.feedburner.com/~ff/CiscoIosHintsAndTricks?a=ZkV7qKHIl7Y:RX3EyTxqzjg:4cEx4HpKnUU"><img src="http://feeds.feedburner.com/~ff/CiscoIosHintsAndTricks?i=ZkV7qKHIl7Y:RX3EyTxqzjg:4cEx4HpKnUU" border="0"></img></a> </div><img src="http://feeds.feedburner.com/~r/CiscoIosHintsAndTricks/~4/ZkV7qKHIl7Y" height="1" width="1"/>Ivan Pepelnjakhttp://www.blogger.com/profile/13457151406311272386noreply@blogger.com2http://blog.ioshints.info/2012/01/best-of-december-2012.htmltag:blogger.com,1999:blog-23021255.post-69238665019526875942012-01-20T12:03:00.000+01:002012-01-20T12:03:29.156+01:00<p>It’s hard for me to admit, but there just might be a <a href="http://blog.ioshints.info/2011/08/quotes-of-week.html">corner use case for split subnets and inter-DC bridging</a>: even if you move a cold VM between data centers in a controlled disaster avoidance process (moving live VMs <a href="http://blog.ioshints.info/2011/09/long-distance-vmotion-for-disaster.html">rarely makes sense</a>), you <a href="http://www.yellow-bricks.com/2012/01/19/avoid-changing-your-vms-ip-in-a-dr-procedure/">might not be able to change its IP address</a> due to hard-coded IP addresses, be it in application code or configuration files.</p><p class="note">Disaster recovery is a different beast: if you’ve lost the primary DC, it doesn’t hurt if you instantiate the same subnet in the backup DC.</p><a href="http://blog.ioshints.info/2012/01/ip-renumbering-in-disaster-avoidance.html#more">Read more ...</a><div class="blogger-post-footer"><img width='1' height='1' src='https://blogger.googleusercontent.com/tracker/23021255-6923866501952687594?l=blog.ioshints.info' alt='' /></div><div class="feedflare"> <a href="http://feeds.feedburner.com/~ff/CiscoIosHintsAndTricks?a=q-N-mTi3eGs:0yROE_GxzHc:yIl2AUoC8zA"><img src="http://feeds.feedburner.com/~ff/CiscoIosHintsAndTricks?d=yIl2AUoC8zA" border="0"></img></a> <a href="http://feeds.feedburner.com/~ff/CiscoIosHintsAndTricks?a=q-N-mTi3eGs:0yROE_GxzHc:qj6IDK7rITs"><img src="http://feeds.feedburner.com/~ff/CiscoIosHintsAndTricks?d=qj6IDK7rITs" border="0"></img></a> <a href="http://feeds.feedburner.com/~ff/CiscoIosHintsAndTricks?a=q-N-mTi3eGs:0yROE_GxzHc:I9og5sOYxJI"><img src="http://feeds.feedburner.com/~ff/CiscoIosHintsAndTricks?d=I9og5sOYxJI" border="0"></img></a> <a href="http://feeds.feedburner.com/~ff/CiscoIosHintsAndTricks?a=q-N-mTi3eGs:0yROE_GxzHc:F7zBnMyn0Lo"><img src="http://feeds.feedburner.com/~ff/CiscoIosHintsAndTricks?i=q-N-mTi3eGs:0yROE_GxzHc:F7zBnMyn0Lo" border="0"></img></a> <a href="http://feeds.feedburner.com/~ff/CiscoIosHintsAndTricks?a=q-N-mTi3eGs:0yROE_GxzHc:V_sGLiPBpWU"><img src="http://feeds.feedburner.com/~ff/CiscoIosHintsAndTricks?i=q-N-mTi3eGs:0yROE_GxzHc:V_sGLiPBpWU" border="0"></img></a> <a href="http://feeds.feedburner.com/~ff/CiscoIosHintsAndTricks?a=q-N-mTi3eGs:0yROE_GxzHc:4cEx4HpKnUU"><img src="http://feeds.feedburner.com/~ff/CiscoIosHintsAndTricks?i=q-N-mTi3eGs:0yROE_GxzHc:4cEx4HpKnUU" border="0"></img></a> </div><img src="http://feeds.feedburner.com/~r/CiscoIosHintsAndTricks/~4/q-N-mTi3eGs" height="1" width="1"/>Ivan Pepelnjakhttp://www.blogger.com/profile/13457151406311272386noreply@blogger.com19http://blog.ioshints.info/2012/01/ip-renumbering-in-disaster-avoidance.htmltag:blogger.com,1999:blog-23021255.post-14998347511110738552012-01-19T13:52:00.001+01:002012-01-19T13:53:07.085+01:00<p>A while ago I described the <a href="http://blog.ioshints.info/2011/03/dhcpv6-radius-integration-cisco-way.html">pre-standard way Cisco IOS used to get delegated IPv6 prefixes from a RADIUS server</a>. Cisco’s documentation <a href="http://www.cisco.com/en/US/prod/collateral/iosswrel/ps8802/ps6968/ps6350/prod_bulletin0900aecd802eaa4f.html">always claimed</a> that Cisco IOS implements <a href="http://tools.ietf.org/html/rfc4818">RFC 4818</a>, but you simply couldn’t get it to work in IOS releases 12.4T or 15.0M. In December I wrote about the <a href="http://blog.ioshints.info/2011/12/dhcpv6-server-on-cisco-ios-making.html">progress Cisco is making on the DHCPv6 front</a> and <em>iord@intracom.com</em><em> </em>commented that IOS 15.1S does support RFC 4818. You know I absolutely had to test that claim ... and it’s true!</p><a href="http://blog.ioshints.info/2012/01/dhcpv6-prefix-delegation-with-radius.html#more">Read more ...</a><div class="blogger-post-footer"><img width='1' height='1' src='https://blogger.googleusercontent.com/tracker/23021255-1499834751111073855?l=blog.ioshints.info' alt='' /></div><div class="feedflare"> <a href="http://feeds.feedburner.com/~ff/CiscoIosHintsAndTricks?a=jkhc8bGfWwY:jcmHxVwYaI0:yIl2AUoC8zA"><img src="http://feeds.feedburner.com/~ff/CiscoIosHintsAndTricks?d=yIl2AUoC8zA" border="0"></img></a> <a href="http://feeds.feedburner.com/~ff/CiscoIosHintsAndTricks?a=jkhc8bGfWwY:jcmHxVwYaI0:qj6IDK7rITs"><img src="http://feeds.feedburner.com/~ff/CiscoIosHintsAndTricks?d=qj6IDK7rITs" border="0"></img></a> <a href="http://feeds.feedburner.com/~ff/CiscoIosHintsAndTricks?a=jkhc8bGfWwY:jcmHxVwYaI0:I9og5sOYxJI"><img src="http://feeds.feedburner.com/~ff/CiscoIosHintsAndTricks?d=I9og5sOYxJI" border="0"></img></a> <a href="http://feeds.feedburner.com/~ff/CiscoIosHintsAndTricks?a=jkhc8bGfWwY:jcmHxVwYaI0:F7zBnMyn0Lo"><img src="http://feeds.feedburner.com/~ff/CiscoIosHintsAndTricks?i=jkhc8bGfWwY:jcmHxVwYaI0:F7zBnMyn0Lo" border="0"></img></a> <a href="http://feeds.feedburner.com/~ff/CiscoIosHintsAndTricks?a=jkhc8bGfWwY:jcmHxVwYaI0:V_sGLiPBpWU"><img src="http://feeds.feedburner.com/~ff/CiscoIosHintsAndTricks?i=jkhc8bGfWwY:jcmHxVwYaI0:V_sGLiPBpWU" border="0"></img></a> <a href="http://feeds.feedburner.com/~ff/CiscoIosHintsAndTricks?a=jkhc8bGfWwY:jcmHxVwYaI0:4cEx4HpKnUU"><img src="http://feeds.feedburner.com/~ff/CiscoIosHintsAndTricks?i=jkhc8bGfWwY:jcmHxVwYaI0:4cEx4HpKnUU" border="0"></img></a> </div><img src="http://feeds.feedburner.com/~r/CiscoIosHintsAndTricks/~4/jkhc8bGfWwY" height="1" width="1"/>Ivan Pepelnjakhttp://www.blogger.com/profile/13457151406311272386noreply@blogger.com2http://blog.ioshints.info/2012/01/dhcpv6-prefix-delegation-with-radius.htmltag:blogger.com,1999:blog-23021255.post-71083977763543343752012-01-19T10:44:00.000+01:002012-01-19T10:44:11.500+01:00<p class="update">2012-01-19: The initial version of this post contained a serious error: Cisco IOS DHCPv6 server does not create host routes; without on-link prefix, the router cannot forward the packets to the attached end-hosts.</p><p>IPv6 hosts can use <em>stateless </em>or <em>stateful </em>autoconfiguration. <a href="http://blog.ioshints.info/2011/10/ipv6-stateless-autoconfiguration-101.html">Stateless address autoconfiguration (SLAAC) uses IPv6 prefixes from Router Advertisement (RA) messages</a>; stateful autoconfiguration uses DHCPv6. The routers can use two flags in RA messages to tell the attached end hosts which method to use:</p><a href="http://blog.ioshints.info/2012/01/ipv6-nd-managed-config-flag-is-just.html#more">Read more ...</a><div class="blogger-post-footer"><img width='1' height='1' src='https://blogger.googleusercontent.com/tracker/23021255-7108397776354334375?l=blog.ioshints.info' alt='' /></div><div class="feedflare"> <a href="http://feeds.feedburner.com/~ff/CiscoIosHintsAndTricks?a=hrsUfh4h1XY:B6Ma9W_sOQI:yIl2AUoC8zA"><img src="http://feeds.feedburner.com/~ff/CiscoIosHintsAndTricks?d=yIl2AUoC8zA" border="0"></img></a> <a href="http://feeds.feedburner.com/~ff/CiscoIosHintsAndTricks?a=hrsUfh4h1XY:B6Ma9W_sOQI:qj6IDK7rITs"><img src="http://feeds.feedburner.com/~ff/CiscoIosHintsAndTricks?d=qj6IDK7rITs" border="0"></img></a> <a href="http://feeds.feedburner.com/~ff/CiscoIosHintsAndTricks?a=hrsUfh4h1XY:B6Ma9W_sOQI:I9og5sOYxJI"><img src="http://feeds.feedburner.com/~ff/CiscoIosHintsAndTricks?d=I9og5sOYxJI" border="0"></img></a> <a href="http://feeds.feedburner.com/~ff/CiscoIosHintsAndTricks?a=hrsUfh4h1XY:B6Ma9W_sOQI:F7zBnMyn0Lo"><img src="http://feeds.feedburner.com/~ff/CiscoIosHintsAndTricks?i=hrsUfh4h1XY:B6Ma9W_sOQI:F7zBnMyn0Lo" border="0"></img></a> <a href="http://feeds.feedburner.com/~ff/CiscoIosHintsAndTricks?a=hrsUfh4h1XY:B6Ma9W_sOQI:V_sGLiPBpWU"><img src="http://feeds.feedburner.com/~ff/CiscoIosHintsAndTricks?i=hrsUfh4h1XY:B6Ma9W_sOQI:V_sGLiPBpWU" border="0"></img></a> <a href="http://feeds.feedburner.com/~ff/CiscoIosHintsAndTricks?a=hrsUfh4h1XY:B6Ma9W_sOQI:4cEx4HpKnUU"><img src="http://feeds.feedburner.com/~ff/CiscoIosHintsAndTricks?i=hrsUfh4h1XY:B6Ma9W_sOQI:4cEx4HpKnUU" border="0"></img></a> </div><img src="http://feeds.feedburner.com/~r/CiscoIosHintsAndTricks/~4/hrsUfh4h1XY" height="1" width="1"/>Ivan Pepelnjakhttp://www.blogger.com/profile/13457151406311272386noreply@blogger.com14http://blog.ioshints.info/2012/01/ipv6-nd-managed-config-flag-is-just.htmltag:blogger.com,1999:blog-23021255.post-17125972233052506412012-01-17T07:03:00.000+01:002012-01-17T07:03:00.612+01:00<p>Most of the DMVPN-related questions I get are a variant of the “<em>how many tunnels/hubs/interfaces/areas do I need for a redundant DMVPN design?</em>” As always, the right answer is “it depends” (and I can always <a href="http://www.ipspace.net/ExpertExpress">help you with your design</a> if you’d like to get a second opinion), but here’s what I’ve learned so far.</p><a href="http://blog.ioshints.info/2012/01/redundant-dmvpn-designs-part-1-basics.html#more">Read more ...</a><div class="blogger-post-footer"><img width='1' height='1' src='https://blogger.googleusercontent.com/tracker/23021255-1712597223305250641?l=blog.ioshints.info' alt='' /></div><div class="feedflare"> <a href="http://feeds.feedburner.com/~ff/CiscoIosHintsAndTricks?a=SYbJe0Tdwqg:iccGY68KL1U:yIl2AUoC8zA"><img src="http://feeds.feedburner.com/~ff/CiscoIosHintsAndTricks?d=yIl2AUoC8zA" border="0"></img></a> <a href="http://feeds.feedburner.com/~ff/CiscoIosHintsAndTricks?a=SYbJe0Tdwqg:iccGY68KL1U:qj6IDK7rITs"><img src="http://feeds.feedburner.com/~ff/CiscoIosHintsAndTricks?d=qj6IDK7rITs" border="0"></img></a> <a href="http://feeds.feedburner.com/~ff/CiscoIosHintsAndTricks?a=SYbJe0Tdwqg:iccGY68KL1U:I9og5sOYxJI"><img src="http://feeds.feedburner.com/~ff/CiscoIosHintsAndTricks?d=I9og5sOYxJI" border="0"></img></a> <a href="http://feeds.feedburner.com/~ff/CiscoIosHintsAndTricks?a=SYbJe0Tdwqg:iccGY68KL1U:F7zBnMyn0Lo"><img src="http://feeds.feedburner.com/~ff/CiscoIosHintsAndTricks?i=SYbJe0Tdwqg:iccGY68KL1U:F7zBnMyn0Lo" border="0"></img></a> <a href="http://feeds.feedburner.com/~ff/CiscoIosHintsAndTricks?a=SYbJe0Tdwqg:iccGY68KL1U:V_sGLiPBpWU"><img src="http://feeds.feedburner.com/~ff/CiscoIosHintsAndTricks?i=SYbJe0Tdwqg:iccGY68KL1U:V_sGLiPBpWU" border="0"></img></a> <a href="http://feeds.feedburner.com/~ff/CiscoIosHintsAndTricks?a=SYbJe0Tdwqg:iccGY68KL1U:4cEx4HpKnUU"><img src="http://feeds.feedburner.com/~ff/CiscoIosHintsAndTricks?i=SYbJe0Tdwqg:iccGY68KL1U:4cEx4HpKnUU" border="0"></img></a> </div><img src="http://feeds.feedburner.com/~r/CiscoIosHintsAndTricks/~4/SYbJe0Tdwqg" height="1" width="1"/>Ivan Pepelnjakhttp://www.blogger.com/profile/13457151406311272386noreply@blogger.com2http://blog.ioshints.info/2012/01/redundant-dmvpn-designs-part-1-basics.htmltag:blogger.com,1999:blog-23021255.post-30474527353708740132012-01-16T07:32:00.000+01:002012-01-16T07:37:03.676+01:00<p>I got plenty of responses to the <a href="http://blog.ioshints.info/2012/01/how-could-we-filter-extraneous-bgp.html"><em>How could we filter extraneous BGP prefixes post</em></a>, some of them referring to emerging technologies and clean-slate ideas, others describing down-to-earth approaches. Thank you all, you’re fantastic!</p><a href="http://blog.ioshints.info/2012/01/filter-inbound-bgp-prefixes-summary.html#more">Read more ...</a><div class="blogger-post-footer"><img width='1' height='1' src='https://blogger.googleusercontent.com/tracker/23021255-3047452735370874013?l=blog.ioshints.info' alt='' /></div><div class="feedflare"> <a href="http://feeds.feedburner.com/~ff/CiscoIosHintsAndTricks?a=hvB_l4yI2zc:jiWBBjH2ln4:yIl2AUoC8zA"><img src="http://feeds.feedburner.com/~ff/CiscoIosHintsAndTricks?d=yIl2AUoC8zA" border="0"></img></a> <a href="http://feeds.feedburner.com/~ff/CiscoIosHintsAndTricks?a=hvB_l4yI2zc:jiWBBjH2ln4:qj6IDK7rITs"><img src="http://feeds.feedburner.com/~ff/CiscoIosHintsAndTricks?d=qj6IDK7rITs" border="0"></img></a> <a href="http://feeds.feedburner.com/~ff/CiscoIosHintsAndTricks?a=hvB_l4yI2zc:jiWBBjH2ln4:I9og5sOYxJI"><img src="http://feeds.feedburner.com/~ff/CiscoIosHintsAndTricks?d=I9og5sOYxJI" border="0"></img></a> <a href="http://feeds.feedburner.com/~ff/CiscoIosHintsAndTricks?a=hvB_l4yI2zc:jiWBBjH2ln4:F7zBnMyn0Lo"><img src="http://feeds.feedburner.com/~ff/CiscoIosHintsAndTricks?i=hvB_l4yI2zc:jiWBBjH2ln4:F7zBnMyn0Lo" border="0"></img></a> <a href="http://feeds.feedburner.com/~ff/CiscoIosHintsAndTricks?a=hvB_l4yI2zc:jiWBBjH2ln4:V_sGLiPBpWU"><img src="http://feeds.feedburner.com/~ff/CiscoIosHintsAndTricks?i=hvB_l4yI2zc:jiWBBjH2ln4:V_sGLiPBpWU" border="0"></img></a> <a href="http://feeds.feedburner.com/~ff/CiscoIosHintsAndTricks?a=hvB_l4yI2zc:jiWBBjH2ln4:4cEx4HpKnUU"><img src="http://feeds.feedburner.com/~ff/CiscoIosHintsAndTricks?i=hvB_l4yI2zc:jiWBBjH2ln4:4cEx4HpKnUU" border="0"></img></a> </div><img src="http://feeds.feedburner.com/~r/CiscoIosHintsAndTricks/~4/hvB_l4yI2zc" height="1" width="1"/>Ivan Pepelnjakhttp://www.blogger.com/profile/13457151406311272386noreply@blogger.com2http://blog.ioshints.info/2012/01/filter-inbound-bgp-prefixes-summary.htmltag:blogger.com,1999:blog-23021255.post-14437252767741462502012-01-15T11:20:00.000+01:002012-01-15T19:11:01.157+01:00<p>Lots of interesting links accumulated in my <a href="https://www.evernote.com/pub/ioshints/Links">Evernote notebook</a> during the last two weeks. Let&#39;s start with a design masterpiece — <a href="http://thereifixedit.failblog.org/2011/12/22/white-trash-repairs-historical-thursday-the-other-manhattan-project/#more-30347">Historical Thursday: The Other Manhattan Project</a>: Almost as good as stretched clusters ... and almost as useful ;)</p><p>And here are the other links in somewhat random order:</p><a href="http://blog.ioshints.info/2012/01/interesting-links-2012-01-15.html#more">Read more ...</a><div class="blogger-post-footer"><img width='1' height='1' src='https://blogger.googleusercontent.com/tracker/23021255-1443725276774146250?l=blog.ioshints.info' alt='' /></div><div class="feedflare"> <a href="http://feeds.feedburner.com/~ff/CiscoIosHintsAndTricks?a=QRoW8ddrAOw:H03LwTb7zwc:yIl2AUoC8zA"><img src="http://feeds.feedburner.com/~ff/CiscoIosHintsAndTricks?d=yIl2AUoC8zA" border="0"></img></a> <a href="http://feeds.feedburner.com/~ff/CiscoIosHintsAndTricks?a=QRoW8ddrAOw:H03LwTb7zwc:qj6IDK7rITs"><img src="http://feeds.feedburner.com/~ff/CiscoIosHintsAndTricks?d=qj6IDK7rITs" border="0"></img></a> <a href="http://feeds.feedburner.com/~ff/CiscoIosHintsAndTricks?a=QRoW8ddrAOw:H03LwTb7zwc:I9og5sOYxJI"><img src="http://feeds.feedburner.com/~ff/CiscoIosHintsAndTricks?d=I9og5sOYxJI" border="0"></img></a> <a href="http://feeds.feedburner.com/~ff/CiscoIosHintsAndTricks?a=QRoW8ddrAOw:H03LwTb7zwc:F7zBnMyn0Lo"><img src="http://feeds.feedburner.com/~ff/CiscoIosHintsAndTricks?i=QRoW8ddrAOw:H03LwTb7zwc:F7zBnMyn0Lo" border="0"></img></a> <a href="http://feeds.feedburner.com/~ff/CiscoIosHintsAndTricks?a=QRoW8ddrAOw:H03LwTb7zwc:V_sGLiPBpWU"><img src="http://feeds.feedburner.com/~ff/CiscoIosHintsAndTricks?i=QRoW8ddrAOw:H03LwTb7zwc:V_sGLiPBpWU" border="0"></img></a> <a href="http://feeds.feedburner.com/~ff/CiscoIosHintsAndTricks?a=QRoW8ddrAOw:H03LwTb7zwc:4cEx4HpKnUU"><img src="http://feeds.feedburner.com/~ff/CiscoIosHintsAndTricks?i=QRoW8ddrAOw:H03LwTb7zwc:4cEx4HpKnUU" border="0"></img></a> </div><img src="http://feeds.feedburner.com/~r/CiscoIosHintsAndTricks/~4/QRoW8ddrAOw" height="1" width="1"/>Ivan Pepelnjakhttp://www.blogger.com/profile/13457151406311272386noreply@blogger.com2http://blog.ioshints.info/2012/01/interesting-links-2012-01-15.htmltag:blogger.com,1999:blog-23021255.post-5348602798946333022012-01-14T11:32:00.000+01:002012-01-14T11:32:50.639+01:00<p>I’ve been blogging regularly for over five years, accumulating almost 1500 posts. It must be quite tasking and time-consuming to leaf through the older posts (not sure anyone ever did that ;), so I decided to use my <a href="http://blog.ioshints.info/2012/01/best-of-2011.html">brand-new Google Analytics add-on</a> to find out which of the old posts are still attracting some attention.</p><p>In January 2007, I focused on CEF and wrote about <a href="http://blog.ioshints.info/2007/01/cef-punted-packets.html">CEF punted packets</a>, <a href="http://blog.ioshints.info/2007/01/cef-punt-adjancency.html">CEF punt adjacency</a> and <a href="http://blog.ioshints.info/2006/12/per-port-cef-load-sharing.html">Per-port CEF load sharing</a>.</p><p>Hot topics in January 2009 included DHCP (<a href="http://blog.ioshints.info/2009/01/decent-dns-dhcp-and-http-server-on-isr.html">Decent DNS, DHCP and HTTP server on an ISR router</a> and <a href="http://blog.ioshints.info/2009/01/flash-based-dhcp-database.html">Flash-based DHCP database</a>) and load sharing (<a href="http://blog.ioshints.info/2009/01/ebgp-multipath-load-sharing-and-cef.html">EBGP multipath load sharing and CEF</a>).</p><a href="http://blog.ioshints.info/2012/01/3-5-years-ago-january-2012.html#more">Read more ...</a><div class="blogger-post-footer"><img width='1' height='1' src='https://blogger.googleusercontent.com/tracker/23021255-534860279894633302?l=blog.ioshints.info' alt='' /></div><div class="feedflare"> <a href="http://feeds.feedburner.com/~ff/CiscoIosHintsAndTricks?a=ash7aspWzR8:n_wg-ueiVZ8:yIl2AUoC8zA"><img src="http://feeds.feedburner.com/~ff/CiscoIosHintsAndTricks?d=yIl2AUoC8zA" border="0"></img></a> <a href="http://feeds.feedburner.com/~ff/CiscoIosHintsAndTricks?a=ash7aspWzR8:n_wg-ueiVZ8:qj6IDK7rITs"><img src="http://feeds.feedburner.com/~ff/CiscoIosHintsAndTricks?d=qj6IDK7rITs" border="0"></img></a> <a href="http://feeds.feedburner.com/~ff/CiscoIosHintsAndTricks?a=ash7aspWzR8:n_wg-ueiVZ8:I9og5sOYxJI"><img src="http://feeds.feedburner.com/~ff/CiscoIosHintsAndTricks?d=I9og5sOYxJI" border="0"></img></a> <a href="http://feeds.feedburner.com/~ff/CiscoIosHintsAndTricks?a=ash7aspWzR8:n_wg-ueiVZ8:F7zBnMyn0Lo"><img src="http://feeds.feedburner.com/~ff/CiscoIosHintsAndTricks?i=ash7aspWzR8:n_wg-ueiVZ8:F7zBnMyn0Lo" border="0"></img></a> <a href="http://feeds.feedburner.com/~ff/CiscoIosHintsAndTricks?a=ash7aspWzR8:n_wg-ueiVZ8:V_sGLiPBpWU"><img src="http://feeds.feedburner.com/~ff/CiscoIosHintsAndTricks?i=ash7aspWzR8:n_wg-ueiVZ8:V_sGLiPBpWU" border="0"></img></a> <a href="http://feeds.feedburner.com/~ff/CiscoIosHintsAndTricks?a=ash7aspWzR8:n_wg-ueiVZ8:4cEx4HpKnUU"><img src="http://feeds.feedburner.com/~ff/CiscoIosHintsAndTricks?i=ash7aspWzR8:n_wg-ueiVZ8:4cEx4HpKnUU" border="0"></img></a> </div><img src="http://feeds.feedburner.com/~r/CiscoIosHintsAndTricks/~4/ash7aspWzR8" height="1" width="1"/>Ivan Pepelnjakhttp://www.blogger.com/profile/13457151406311272386noreply@blogger.com0http://blog.ioshints.info/2012/01/3-5-years-ago-january-2012.htmltag:blogger.com,1999:blog-23021255.post-43094751343018976012012-01-13T14:14:00.000+01:002012-01-13T14:14:48.956+01:00<p>Every so often I get a question along the lines of “<em>could I see a sample of your webinars before I buy them?</em>” To answer the question, I <a href="http://demo.ipspace.net/bin/start">created a new web site</a> that includes the videos I previously <a href="http://www.youtube.com/user/IvanPx">published on YouTube</a>, as well as plenty of information on what exactly you get when you <a href="http://www.ipspace.net/Recordings">buy a recording</a> or the <a href="http://www.ipspace.net/Subscription">yearly subscription</a>. Your feedback on site outline/design and its contents is highly appreciated!</p><p style="text-align: right;">Visit <a href="http://demo.ipspace.net/bin/start">demo.ipSpace.net</a></p><div class="blogger-post-footer"><img width='1' height='1' src='https://blogger.googleusercontent.com/tracker/23021255-4309475134301897601?l=blog.ioshints.info' alt='' /></div><div class="feedflare"> <a href="http://feeds.feedburner.com/~ff/CiscoIosHintsAndTricks?a=VwUSsw73WTw:JMI2H7RiDNM:yIl2AUoC8zA"><img src="http://feeds.feedburner.com/~ff/CiscoIosHintsAndTricks?d=yIl2AUoC8zA" border="0"></img></a> <a href="http://feeds.feedburner.com/~ff/CiscoIosHintsAndTricks?a=VwUSsw73WTw:JMI2H7RiDNM:qj6IDK7rITs"><img src="http://feeds.feedburner.com/~ff/CiscoIosHintsAndTricks?d=qj6IDK7rITs" border="0"></img></a> <a href="http://feeds.feedburner.com/~ff/CiscoIosHintsAndTricks?a=VwUSsw73WTw:JMI2H7RiDNM:I9og5sOYxJI"><img src="http://feeds.feedburner.com/~ff/CiscoIosHintsAndTricks?d=I9og5sOYxJI" border="0"></img></a> <a href="http://feeds.feedburner.com/~ff/CiscoIosHintsAndTricks?a=VwUSsw73WTw:JMI2H7RiDNM:F7zBnMyn0Lo"><img src="http://feeds.feedburner.com/~ff/CiscoIosHintsAndTricks?i=VwUSsw73WTw:JMI2H7RiDNM:F7zBnMyn0Lo" border="0"></img></a> <a href="http://feeds.feedburner.com/~ff/CiscoIosHintsAndTricks?a=VwUSsw73WTw:JMI2H7RiDNM:V_sGLiPBpWU"><img src="http://feeds.feedburner.com/~ff/CiscoIosHintsAndTricks?i=VwUSsw73WTw:JMI2H7RiDNM:V_sGLiPBpWU" border="0"></img></a> <a href="http://feeds.feedburner.com/~ff/CiscoIosHintsAndTricks?a=VwUSsw73WTw:JMI2H7RiDNM:4cEx4HpKnUU"><img src="http://feeds.feedburner.com/~ff/CiscoIosHintsAndTricks?i=VwUSsw73WTw:JMI2H7RiDNM:4cEx4HpKnUU" border="0"></img></a> </div><img src="http://feeds.feedburner.com/~r/CiscoIosHintsAndTricks/~4/VwUSsw73WTw" height="1" width="1"/>Ivan Pepelnjakhttp://www.blogger.com/profile/13457151406311272386noreply@blogger.com2http://blog.ioshints.info/2012/01/ipspace-webinars-peek-before-you-buy.htmltag:blogger.com,1999:blog-23021255.post-29733413187997777302012-01-12T06:57:00.000+01:002012-01-12T06:57:00.565+01:00<p>Did you know that <a href="http://www.cidr-report.org/as2.0/#Gains">approximately 40% of BGP prefixes polluting your RIB and FIB</a> are not needed, as they could be either aggregated or suppressed (because an aggregate is already announced)? We definitely need “<a href="http://www.renesys.com/blog/2009/02/the-flap-heard-around-the-worl.shtml">driver’s license for the Internet</a>”, but that’s not likely to happen, and in the meantime everyone has to keep buying larger boxes to cope with people who cannot configure their BGP routing correctly.</p><a href="http://blog.ioshints.info/2012/01/how-could-we-filter-extraneous-bgp.html#more">Read more ...</a><div class="blogger-post-footer"><img width='1' height='1' src='https://blogger.googleusercontent.com/tracker/23021255-2973341318799777730?l=blog.ioshints.info' alt='' /></div><div class="feedflare"> <a href="http://feeds.feedburner.com/~ff/CiscoIosHintsAndTricks?a=3JNsdozOr4A:I24IBtE0LbI:yIl2AUoC8zA"><img src="http://feeds.feedburner.com/~ff/CiscoIosHintsAndTricks?d=yIl2AUoC8zA" border="0"></img></a> <a href="http://feeds.feedburner.com/~ff/CiscoIosHintsAndTricks?a=3JNsdozOr4A:I24IBtE0LbI:qj6IDK7rITs"><img src="http://feeds.feedburner.com/~ff/CiscoIosHintsAndTricks?d=qj6IDK7rITs" border="0"></img></a> <a href="http://feeds.feedburner.com/~ff/CiscoIosHintsAndTricks?a=3JNsdozOr4A:I24IBtE0LbI:I9og5sOYxJI"><img src="http://feeds.feedburner.com/~ff/CiscoIosHintsAndTricks?d=I9og5sOYxJI" border="0"></img></a> <a href="http://feeds.feedburner.com/~ff/CiscoIosHintsAndTricks?a=3JNsdozOr4A:I24IBtE0LbI:F7zBnMyn0Lo"><img src="http://feeds.feedburner.com/~ff/CiscoIosHintsAndTricks?i=3JNsdozOr4A:I24IBtE0LbI:F7zBnMyn0Lo" border="0"></img></a> <a href="http://feeds.feedburner.com/~ff/CiscoIosHintsAndTricks?a=3JNsdozOr4A:I24IBtE0LbI:V_sGLiPBpWU"><img src="http://feeds.feedburner.com/~ff/CiscoIosHintsAndTricks?i=3JNsdozOr4A:I24IBtE0LbI:V_sGLiPBpWU" border="0"></img></a> <a href="http://feeds.feedburner.com/~ff/CiscoIosHintsAndTricks?a=3JNsdozOr4A:I24IBtE0LbI:4cEx4HpKnUU"><img src="http://feeds.feedburner.com/~ff/CiscoIosHintsAndTricks?i=3JNsdozOr4A:I24IBtE0LbI:4cEx4HpKnUU" border="0"></img></a> </div><img src="http://feeds.feedburner.com/~r/CiscoIosHintsAndTricks/~4/3JNsdozOr4A" height="1" width="1"/>Ivan Pepelnjakhttp://www.blogger.com/profile/13457151406311272386noreply@blogger.com12http://blog.ioshints.info/2012/01/how-could-we-filter-extraneous-bgp.htmltag:blogger.com,1999:blog-23021255.post-60130871285449498802012-01-11T07:04:00.000+01:002012-01-11T07:04:01.339+01:00<p>I got a follow-up question to the <a href="http://blog.ioshints.info/2012/01/should-i-use-6pe-or-native-ipv6.html"><em>Should I use 6PE or native IPv6</em></a> post: “<em>Am I remembering correctly that if you run IPv6 native throughout the network you need to enable BGP on all routers, even P routers? Why is that?</em>” I <a href="http://blog.ioshints.info/2008/03/use-mpls-to-scale-your-internet.html">wrote about BGP-free core before</a>, but evidently wasn’t clear enough, so I’ll try to fix that error.</p><a href="http://blog.ioshints.info/2012/01/bgp-free-service-provider-core-in.html#more">Read more ...</a><div class="blogger-post-footer"><img width='1' height='1' src='https://blogger.googleusercontent.com/tracker/23021255-6013087128544949880?l=blog.ioshints.info' alt='' /></div><div class="feedflare"> <a href="http://feeds.feedburner.com/~ff/CiscoIosHintsAndTricks?a=KLPI0O47roQ:lOTvLV9_2AM:yIl2AUoC8zA"><img src="http://feeds.feedburner.com/~ff/CiscoIosHintsAndTricks?d=yIl2AUoC8zA" border="0"></img></a> <a href="http://feeds.feedburner.com/~ff/CiscoIosHintsAndTricks?a=KLPI0O47roQ:lOTvLV9_2AM:qj6IDK7rITs"><img src="http://feeds.feedburner.com/~ff/CiscoIosHintsAndTricks?d=qj6IDK7rITs" border="0"></img></a> <a href="http://feeds.feedburner.com/~ff/CiscoIosHintsAndTricks?a=KLPI0O47roQ:lOTvLV9_2AM:I9og5sOYxJI"><img src="http://feeds.feedburner.com/~ff/CiscoIosHintsAndTricks?d=I9og5sOYxJI" border="0"></img></a> <a href="http://feeds.feedburner.com/~ff/CiscoIosHintsAndTricks?a=KLPI0O47roQ:lOTvLV9_2AM:F7zBnMyn0Lo"><img src="http://feeds.feedburner.com/~ff/CiscoIosHintsAndTricks?i=KLPI0O47roQ:lOTvLV9_2AM:F7zBnMyn0Lo" border="0"></img></a> <a href="http://feeds.feedburner.com/~ff/CiscoIosHintsAndTricks?a=KLPI0O47roQ:lOTvLV9_2AM:V_sGLiPBpWU"><img src="http://feeds.feedburner.com/~ff/CiscoIosHintsAndTricks?i=KLPI0O47roQ:lOTvLV9_2AM:V_sGLiPBpWU" border="0"></img></a> <a href="http://feeds.feedburner.com/~ff/CiscoIosHintsAndTricks?a=KLPI0O47roQ:lOTvLV9_2AM:4cEx4HpKnUU"><img src="http://feeds.feedburner.com/~ff/CiscoIosHintsAndTricks?i=KLPI0O47roQ:lOTvLV9_2AM:4cEx4HpKnUU" border="0"></img></a> </div><img src="http://feeds.feedburner.com/~r/CiscoIosHintsAndTricks/~4/KLPI0O47roQ" height="1" width="1"/>Ivan Pepelnjakhttp://www.blogger.com/profile/13457151406311272386noreply@blogger.com5http://blog.ioshints.info/2012/01/bgp-free-service-provider-core-in.htmltag:blogger.com,1999:blog-23021255.post-86621753795699546532012-01-10T08:56:00.000+01:002012-01-10T16:22:49.695+01:00<p>Brad Hedlund wrote a <a href="http://bradhedlund.com/2011/12/22/on-optimizing-traffic-for-network-virtualization/">thought-provoking article</a> a few weeks ago, claiming that the <a href="http://blog.scottlowe.org/2011/12/07/revisiting-vxlan-and-layer-3-connectivity/">horseshoes</a> (or <a href="http://blog.ioshints.info/2011/02/traffic-trombone-what-it-is-and-how-you.html">trombones</a>) and <a href="http://blog.ioshints.info/2011/10/vxlan-termination-on-physical-devices.html">spaghetti</a> created by virtual workloads and appliances deployed anywhere in the network don’t matter much with new data center designs that behave like distributed switches. In theory, he’s right. In practice, less so.</p><a href="http://blog.ioshints.info/2012/01/can-we-really-ignore-spaghetti-and.html#more">Read more ...</a><div class="blogger-post-footer"><img width='1' height='1' src='https://blogger.googleusercontent.com/tracker/23021255-8662175379569954653?l=blog.ioshints.info' alt='' /></div><div class="feedflare"> <a href="http://feeds.feedburner.com/~ff/CiscoIosHintsAndTricks?a=6RLwg-Epzco:yFL84jdSCLI:yIl2AUoC8zA"><img src="http://feeds.feedburner.com/~ff/CiscoIosHintsAndTricks?d=yIl2AUoC8zA" border="0"></img></a> <a href="http://feeds.feedburner.com/~ff/CiscoIosHintsAndTricks?a=6RLwg-Epzco:yFL84jdSCLI:qj6IDK7rITs"><img src="http://feeds.feedburner.com/~ff/CiscoIosHintsAndTricks?d=qj6IDK7rITs" border="0"></img></a> <a href="http://feeds.feedburner.com/~ff/CiscoIosHintsAndTricks?a=6RLwg-Epzco:yFL84jdSCLI:I9og5sOYxJI"><img src="http://feeds.feedburner.com/~ff/CiscoIosHintsAndTricks?d=I9og5sOYxJI" border="0"></img></a> <a href="http://feeds.feedburner.com/~ff/CiscoIosHintsAndTricks?a=6RLwg-Epzco:yFL84jdSCLI:F7zBnMyn0Lo"><img src="http://feeds.feedburner.com/~ff/CiscoIosHintsAndTricks?i=6RLwg-Epzco:yFL84jdSCLI:F7zBnMyn0Lo" border="0"></img></a> <a href="http://feeds.feedburner.com/~ff/CiscoIosHintsAndTricks?a=6RLwg-Epzco:yFL84jdSCLI:V_sGLiPBpWU"><img src="http://feeds.feedburner.com/~ff/CiscoIosHintsAndTricks?i=6RLwg-Epzco:yFL84jdSCLI:V_sGLiPBpWU" border="0"></img></a> <a href="http://feeds.feedburner.com/~ff/CiscoIosHintsAndTricks?a=6RLwg-Epzco:yFL84jdSCLI:4cEx4HpKnUU"><img src="http://feeds.feedburner.com/~ff/CiscoIosHintsAndTricks?i=6RLwg-Epzco:yFL84jdSCLI:4cEx4HpKnUU" border="0"></img></a> </div><img src="http://feeds.feedburner.com/~r/CiscoIosHintsAndTricks/~4/6RLwg-Epzco" height="1" width="1"/>Ivan Pepelnjakhttp://www.blogger.com/profile/13457151406311272386noreply@blogger.com0http://blog.ioshints.info/2012/01/can-we-really-ignore-spaghetti-and.htmltag:blogger.com,1999:blog-23021255.post-26291077785873398162012-01-09T06:41:00.000+01:002012-01-09T06:41:01.428+01:00<p>A few weeks ago I <a href="http://blog.ioshints.info/2011/12/help-me-plan-new-webinars-in-2012.html">asked you to help me plan the new webinars in 2012</a>. More than a 100 readers responded – a huge thank you (there’s a small present waiting in your Inbox if you left your e-mail address)!</p><p>I expected some of the results, others totally surprised me. Here are the winners (you can also <a href="http://www.ipspace.net/files/Webinars_2012P.pdf">download the full report</a>).</p><a href="http://blog.ioshints.info/2012/01/webinars-in-2012-survey-results.html#more">Read more ...</a><div class="blogger-post-footer"><img width='1' height='1' src='https://blogger.googleusercontent.com/tracker/23021255-2629107778587339816?l=blog.ioshints.info' alt='' /></div><div class="feedflare"> <a href="http://feeds.feedburner.com/~ff/CiscoIosHintsAndTricks?a=jsqrzKCTmhA:B1ujKF-plE0:yIl2AUoC8zA"><img src="http://feeds.feedburner.com/~ff/CiscoIosHintsAndTricks?d=yIl2AUoC8zA" border="0"></img></a> <a href="http://feeds.feedburner.com/~ff/CiscoIosHintsAndTricks?a=jsqrzKCTmhA:B1ujKF-plE0:qj6IDK7rITs"><img src="http://feeds.feedburner.com/~ff/CiscoIosHintsAndTricks?d=qj6IDK7rITs" border="0"></img></a> <a href="http://feeds.feedburner.com/~ff/CiscoIosHintsAndTricks?a=jsqrzKCTmhA:B1ujKF-plE0:I9og5sOYxJI"><img src="http://feeds.feedburner.com/~ff/CiscoIosHintsAndTricks?d=I9og5sOYxJI" border="0"></img></a> <a href="http://feeds.feedburner.com/~ff/CiscoIosHintsAndTricks?a=jsqrzKCTmhA:B1ujKF-plE0:F7zBnMyn0Lo"><img src="http://feeds.feedburner.com/~ff/CiscoIosHintsAndTricks?i=jsqrzKCTmhA:B1ujKF-plE0:F7zBnMyn0Lo" border="0"></img></a> <a href="http://feeds.feedburner.com/~ff/CiscoIosHintsAndTricks?a=jsqrzKCTmhA:B1ujKF-plE0:V_sGLiPBpWU"><img src="http://feeds.feedburner.com/~ff/CiscoIosHintsAndTricks?i=jsqrzKCTmhA:B1ujKF-plE0:V_sGLiPBpWU" border="0"></img></a> <a href="http://feeds.feedburner.com/~ff/CiscoIosHintsAndTricks?a=jsqrzKCTmhA:B1ujKF-plE0:4cEx4HpKnUU"><img src="http://feeds.feedburner.com/~ff/CiscoIosHintsAndTricks?i=jsqrzKCTmhA:B1ujKF-plE0:4cEx4HpKnUU" border="0"></img></a> </div><img src="http://feeds.feedburner.com/~r/CiscoIosHintsAndTricks/~4/jsqrzKCTmhA" height="1" width="1"/>Ivan Pepelnjakhttp://www.blogger.com/profile/13457151406311272386noreply@blogger.com1http://blog.ioshints.info/2012/01/webinars-in-2012-survey-results.htmltag:blogger.com,1999:blog-23021255.post-92065321612257537052012-01-05T10:01:00.001+01:002012-01-06T05:55:33.643+01:00<p>One of my students was watching the <a href="http://www.ipspace.net/Building_IPv6_Service_Provider_Core"><em>Building IPv6 Service Provider Core</em></a> webinar and wondered whether he should use 6PE or native IPv6 transport:</p><blockquote class="cite">Could you explain further why it is better to choose 6PE over running IPv6 in the core? I have to implement IPv6 where I work (a small ISP) and need to fully understand why I should choose a certain implementation.</blockquote><p>Here’s a short decision tree that should help you make that decision:</p><a href="http://blog.ioshints.info/2012/01/should-i-use-6pe-or-native-ipv6.html#more">Read more ...</a><div class="blogger-post-footer"><img width='1' height='1' src='https://blogger.googleusercontent.com/tracker/23021255-9206532161225753705?l=blog.ioshints.info' alt='' /></div><div class="feedflare"> <a href="http://feeds.feedburner.com/~ff/CiscoIosHintsAndTricks?a=YOa_YERC0dE:zbt-m3yMwBo:yIl2AUoC8zA"><img src="http://feeds.feedburner.com/~ff/CiscoIosHintsAndTricks?d=yIl2AUoC8zA" border="0"></img></a> <a href="http://feeds.feedburner.com/~ff/CiscoIosHintsAndTricks?a=YOa_YERC0dE:zbt-m3yMwBo:qj6IDK7rITs"><img src="http://feeds.feedburner.com/~ff/CiscoIosHintsAndTricks?d=qj6IDK7rITs" border="0"></img></a> <a href="http://feeds.feedburner.com/~ff/CiscoIosHintsAndTricks?a=YOa_YERC0dE:zbt-m3yMwBo:I9og5sOYxJI"><img src="http://feeds.feedburner.com/~ff/CiscoIosHintsAndTricks?d=I9og5sOYxJI" border="0"></img></a> <a href="http://feeds.feedburner.com/~ff/CiscoIosHintsAndTricks?a=YOa_YERC0dE:zbt-m3yMwBo:F7zBnMyn0Lo"><img src="http://feeds.feedburner.com/~ff/CiscoIosHintsAndTricks?i=YOa_YERC0dE:zbt-m3yMwBo:F7zBnMyn0Lo" border="0"></img></a> <a href="http://feeds.feedburner.com/~ff/CiscoIosHintsAndTricks?a=YOa_YERC0dE:zbt-m3yMwBo:V_sGLiPBpWU"><img src="http://feeds.feedburner.com/~ff/CiscoIosHintsAndTricks?i=YOa_YERC0dE:zbt-m3yMwBo:V_sGLiPBpWU" border="0"></img></a> <a href="http://feeds.feedburner.com/~ff/CiscoIosHintsAndTricks?a=YOa_YERC0dE:zbt-m3yMwBo:4cEx4HpKnUU"><img src="http://feeds.feedburner.com/~ff/CiscoIosHintsAndTricks?i=YOa_YERC0dE:zbt-m3yMwBo:4cEx4HpKnUU" border="0"></img></a> </div><img src="http://feeds.feedburner.com/~r/CiscoIosHintsAndTricks/~4/YOa_YERC0dE" height="1" width="1"/>Ivan Pepelnjakhttp://www.blogger.com/profile/13457151406311272386noreply@blogger.com12http://blog.ioshints.info/2012/01/should-i-use-6pe-or-native-ipv6.htmltag:blogger.com,1999:blog-23021255.post-85109394118162688742012-01-04T08:21:00.003+01:002012-01-04T08:21:40.244+01:00<p>Anton sent me an interesting question:</p><blockquote class="cite">Most IP phones have a network facing port and a port for user to connect the PC. Today a user plugged in both of these ports into the switch. It looks like phone filters out BPDUs, so the switch did not catch this loop. Do you know of a feature or design that would be able to catch/prevent this type of event?</blockquote><p>My answer would be “no, there’s nothing you can do if you have a broken device that acts like a STP-less switch” but you know I’m not a switching or IP telephony guru. Any ideas?</p><div class="blogger-post-footer"><img width='1' height='1' src='https://blogger.googleusercontent.com/tracker/23021255-8510939411816268874?l=blog.ioshints.info' alt='' /></div><div class="feedflare"> <a href="http://feeds.feedburner.com/~ff/CiscoIosHintsAndTricks?a=Duh1xsZo74k:_tHQzUq9IDY:yIl2AUoC8zA"><img src="http://feeds.feedburner.com/~ff/CiscoIosHintsAndTricks?d=yIl2AUoC8zA" border="0"></img></a> <a href="http://feeds.feedburner.com/~ff/CiscoIosHintsAndTricks?a=Duh1xsZo74k:_tHQzUq9IDY:qj6IDK7rITs"><img src="http://feeds.feedburner.com/~ff/CiscoIosHintsAndTricks?d=qj6IDK7rITs" border="0"></img></a> <a href="http://feeds.feedburner.com/~ff/CiscoIosHintsAndTricks?a=Duh1xsZo74k:_tHQzUq9IDY:I9og5sOYxJI"><img src="http://feeds.feedburner.com/~ff/CiscoIosHintsAndTricks?d=I9og5sOYxJI" border="0"></img></a> <a href="http://feeds.feedburner.com/~ff/CiscoIosHintsAndTricks?a=Duh1xsZo74k:_tHQzUq9IDY:F7zBnMyn0Lo"><img src="http://feeds.feedburner.com/~ff/CiscoIosHintsAndTricks?i=Duh1xsZo74k:_tHQzUq9IDY:F7zBnMyn0Lo" border="0"></img></a> <a href="http://feeds.feedburner.com/~ff/CiscoIosHintsAndTricks?a=Duh1xsZo74k:_tHQzUq9IDY:V_sGLiPBpWU"><img src="http://feeds.feedburner.com/~ff/CiscoIosHintsAndTricks?i=Duh1xsZo74k:_tHQzUq9IDY:V_sGLiPBpWU" border="0"></img></a> <a href="http://feeds.feedburner.com/~ff/CiscoIosHintsAndTricks?a=Duh1xsZo74k:_tHQzUq9IDY:4cEx4HpKnUU"><img src="http://feeds.feedburner.com/~ff/CiscoIosHintsAndTricks?i=Duh1xsZo74k:_tHQzUq9IDY:4cEx4HpKnUU" border="0"></img></a> </div><img src="http://feeds.feedburner.com/~r/CiscoIosHintsAndTricks/~4/Duh1xsZo74k" height="1" width="1"/>Ivan Pepelnjakhttp://www.blogger.com/profile/13457151406311272386noreply@blogger.com23http://blog.ioshints.info/2012/01/prevent-bridging-loops-without-bpdus.htmltag:blogger.com,1999:blog-23021255.post-46059606645424523382012-01-03T06:32:00.000+01:002012-01-06T05:55:43.611+01:00<p>Aleksej sent me an intriguing question: “<em>Can the /48 PI block that a global company is assigned be attached to any region, or it is region-specific?</em>”, or, more specifically:</p><blockquote class="cite">Imagine a company with major DC with public services in EMEA. Centralized internet break-out in Europe fails and this DC must be reachable from Asia or America - but with the same IPv6 address? That would require Asia or America&#39;s ISPs to accept injection of this same subnet in their region. Do they do that?</blockquote><p>In theory, the answer is <em>yes</em>. In practice, some global organizations are hedging their bets.</p><a href="http://blog.ioshints.info/2012/01/are-provider-independent-ipv6-prefixes.html#more">Read more ...</a><div class="blogger-post-footer"><img width='1' height='1' src='https://blogger.googleusercontent.com/tracker/23021255-4605960664542452338?l=blog.ioshints.info' alt='' /></div><div class="feedflare"> <a href="http://feeds.feedburner.com/~ff/CiscoIosHintsAndTricks?a=q1ZEfgQ6N48:xjkYOKVqHOg:yIl2AUoC8zA"><img src="http://feeds.feedburner.com/~ff/CiscoIosHintsAndTricks?d=yIl2AUoC8zA" border="0"></img></a> <a href="http://feeds.feedburner.com/~ff/CiscoIosHintsAndTricks?a=q1ZEfgQ6N48:xjkYOKVqHOg:qj6IDK7rITs"><img src="http://feeds.feedburner.com/~ff/CiscoIosHintsAndTricks?d=qj6IDK7rITs" border="0"></img></a> <a href="http://feeds.feedburner.com/~ff/CiscoIosHintsAndTricks?a=q1ZEfgQ6N48:xjkYOKVqHOg:I9og5sOYxJI"><img src="http://feeds.feedburner.com/~ff/CiscoIosHintsAndTricks?d=I9og5sOYxJI" border="0"></img></a> <a href="http://feeds.feedburner.com/~ff/CiscoIosHintsAndTricks?a=q1ZEfgQ6N48:xjkYOKVqHOg:F7zBnMyn0Lo"><img src="http://feeds.feedburner.com/~ff/CiscoIosHintsAndTricks?i=q1ZEfgQ6N48:xjkYOKVqHOg:F7zBnMyn0Lo" border="0"></img></a> <a href="http://feeds.feedburner.com/~ff/CiscoIosHintsAndTricks?a=q1ZEfgQ6N48:xjkYOKVqHOg:V_sGLiPBpWU"><img src="http://feeds.feedburner.com/~ff/CiscoIosHintsAndTricks?i=q1ZEfgQ6N48:xjkYOKVqHOg:V_sGLiPBpWU" border="0"></img></a> <a href="http://feeds.feedburner.com/~ff/CiscoIosHintsAndTricks?a=q1ZEfgQ6N48:xjkYOKVqHOg:4cEx4HpKnUU"><img src="http://feeds.feedburner.com/~ff/CiscoIosHintsAndTricks?i=q1ZEfgQ6N48:xjkYOKVqHOg:4cEx4HpKnUU" border="0"></img></a> </div><img src="http://feeds.feedburner.com/~r/CiscoIosHintsAndTricks/~4/q1ZEfgQ6N48" height="1" width="1"/>Ivan Pepelnjakhttp://www.blogger.com/profile/13457151406311272386noreply@blogger.com6http://blog.ioshints.info/2012/01/are-provider-independent-ipv6-prefixes.htmltag:blogger.com,1999:blog-23021255.post-48702547621625841312012-01-01T09:00:00.000+01:002012-01-01T09:00:05.269+01:00<p>Having nothing better to do in the last few days of 2011, I wrote a simple application that extracts data from Google Analytics. Here are the results for my blog:</p><h4>Most visited blog posts in 2011</h4><p>Not surprisingly, the most-popular blog posts were written years ago:</p><a href="http://blog.ioshints.info/2012/01/best-of-2011.html#more">Read more ...</a><div class="blogger-post-footer"><img width='1' height='1' src='https://blogger.googleusercontent.com/tracker/23021255-4870254762162584131?l=blog.ioshints.info' alt='' /></div><div class="feedflare"> <a href="http://feeds.feedburner.com/~ff/CiscoIosHintsAndTricks?a=z1q1Z0Q1TIQ:GxTv0puh3UI:yIl2AUoC8zA"><img src="http://feeds.feedburner.com/~ff/CiscoIosHintsAndTricks?d=yIl2AUoC8zA" border="0"></img></a> <a href="http://feeds.feedburner.com/~ff/CiscoIosHintsAndTricks?a=z1q1Z0Q1TIQ:GxTv0puh3UI:qj6IDK7rITs"><img src="http://feeds.feedburner.com/~ff/CiscoIosHintsAndTricks?d=qj6IDK7rITs" border="0"></img></a> <a href="http://feeds.feedburner.com/~ff/CiscoIosHintsAndTricks?a=z1q1Z0Q1TIQ:GxTv0puh3UI:I9og5sOYxJI"><img src="http://feeds.feedburner.com/~ff/CiscoIosHintsAndTricks?d=I9og5sOYxJI" border="0"></img></a> <a href="http://feeds.feedburner.com/~ff/CiscoIosHintsAndTricks?a=z1q1Z0Q1TIQ:GxTv0puh3UI:F7zBnMyn0Lo"><img src="http://feeds.feedburner.com/~ff/CiscoIosHintsAndTricks?i=z1q1Z0Q1TIQ:GxTv0puh3UI:F7zBnMyn0Lo" border="0"></img></a> <a href="http://feeds.feedburner.com/~ff/CiscoIosHintsAndTricks?a=z1q1Z0Q1TIQ:GxTv0puh3UI:V_sGLiPBpWU"><img src="http://feeds.feedburner.com/~ff/CiscoIosHintsAndTricks?i=z1q1Z0Q1TIQ:GxTv0puh3UI:V_sGLiPBpWU" border="0"></img></a> <a href="http://feeds.feedburner.com/~ff/CiscoIosHintsAndTricks?a=z1q1Z0Q1TIQ:GxTv0puh3UI:4cEx4HpKnUU"><img src="http://feeds.feedburner.com/~ff/CiscoIosHintsAndTricks?i=z1q1Z0Q1TIQ:GxTv0puh3UI:4cEx4HpKnUU" border="0"></img></a> </div><img src="http://feeds.feedburner.com/~r/CiscoIosHintsAndTricks/~4/z1q1Z0Q1TIQ" height="1" width="1"/>Ivan Pepelnjakhttp://www.blogger.com/profile/13457151406311272386noreply@blogger.com3http://blog.ioshints.info/2012/01/best-of-2011.htmltag:blogger.com,1999:blog-23021255.post-9112367730162594522011-12-31T09:37:00.000+01:002011-12-31T09:37:00.249+01:00<p>Last batch of interesting links collected in 2011 ... starting with <a href="http://www.fragmentationneeded.net/2011/12/pricing-and-trading-networks-down-is-up.html">Pricing and Trading Networks: Down is Up, Left is Right</a>: A fantastic post from Chris Marget explaining the behavior of trading floor networks. For me, it was an amazing view into a parallel universe with a completely different set of physical laws.</p><a href="http://blog.ioshints.info/2011/12/interesting-links-2011-12-31.html#more">Read more ...</a><div class="blogger-post-footer"><img width='1' height='1' src='https://blogger.googleusercontent.com/tracker/23021255-911236773016259452?l=blog.ioshints.info' alt='' /></div><div class="feedflare"> <a href="http://feeds.feedburner.com/~ff/CiscoIosHintsAndTricks?a=NhYMH2C5gCk:HNyb-MzSKbU:yIl2AUoC8zA"><img src="http://feeds.feedburner.com/~ff/CiscoIosHintsAndTricks?d=yIl2AUoC8zA" border="0"></img></a> <a href="http://feeds.feedburner.com/~ff/CiscoIosHintsAndTricks?a=NhYMH2C5gCk:HNyb-MzSKbU:qj6IDK7rITs"><img src="http://feeds.feedburner.com/~ff/CiscoIosHintsAndTricks?d=qj6IDK7rITs" border="0"></img></a> <a href="http://feeds.feedburner.com/~ff/CiscoIosHintsAndTricks?a=NhYMH2C5gCk:HNyb-MzSKbU:I9og5sOYxJI"><img src="http://feeds.feedburner.com/~ff/CiscoIosHintsAndTricks?d=I9og5sOYxJI" border="0"></img></a> <a href="http://feeds.feedburner.com/~ff/CiscoIosHintsAndTricks?a=NhYMH2C5gCk:HNyb-MzSKbU:F7zBnMyn0Lo"><img src="http://feeds.feedburner.com/~ff/CiscoIosHintsAndTricks?i=NhYMH2C5gCk:HNyb-MzSKbU:F7zBnMyn0Lo" border="0"></img></a> <a href="http://feeds.feedburner.com/~ff/CiscoIosHintsAndTricks?a=NhYMH2C5gCk:HNyb-MzSKbU:V_sGLiPBpWU"><img src="http://feeds.feedburner.com/~ff/CiscoIosHintsAndTricks?i=NhYMH2C5gCk:HNyb-MzSKbU:V_sGLiPBpWU" border="0"></img></a> <a href="http://feeds.feedburner.com/~ff/CiscoIosHintsAndTricks?a=NhYMH2C5gCk:HNyb-MzSKbU:4cEx4HpKnUU"><img src="http://feeds.feedburner.com/~ff/CiscoIosHintsAndTricks?i=NhYMH2C5gCk:HNyb-MzSKbU:4cEx4HpKnUU" border="0"></img></a> </div><img src="http://feeds.feedburner.com/~r/CiscoIosHintsAndTricks/~4/NhYMH2C5gCk" height="1" width="1"/>Ivan Pepelnjakhttp://www.blogger.com/profile/13457151406311272386noreply@blogger.com0http://blog.ioshints.info/2011/12/interesting-links-2011-12-31.htmltag:blogger.com,1999:blog-23021255.post-23640694520275478362011-12-23T13:27:00.000+01:002011-12-23T13:27:01.237+01:00<p>2011 was a fantastic year for a networking geek, and youwere awesome – helping me figure out the intricacies of new technologies,fixing my errors, and asking so many great questions that prompted me to divedeeper into the rabbit holes. I owe you a huge Thank you!</p><p>I hope you’ll be able to shut down your smartphones andpagers in the next few days and spend a few relaxing moments with your families …and I wish you great networking in 2012!</p><div class="separator" style="clear: both; text-align: center;"><a href="http://3.bp.blogspot.com/-_7ph1m6HogE/TvMgUAjNBsI/AAAAAAAAEok/FMyN3d6Topw/s1600/611100main_snow-angel-hubble1600_1024-768.jpg" imageanchor="1" style="margin-left:1em; margin-right:1em"><img border="0" height="300" width="400" src="http://3.bp.blogspot.com/-_7ph1m6HogE/TvMgUAjNBsI/AAAAAAAAEok/FMyN3d6Topw/s400/611100main_snow-angel-hubble1600_1024-768.jpg" /></a><br />To keep the geeky spirit: snow angel as <a href="http://www.nasa.gov/multimedia/imagegallery/image_feature_2131.html">seen by Hubble</a></div><div class="blogger-post-footer"><img width='1' height='1' src='https://blogger.googleusercontent.com/tracker/23021255-2364069452027547836?l=blog.ioshints.info' alt='' /></div><div class="feedflare"> <a href="http://feeds.feedburner.com/~ff/CiscoIosHintsAndTricks?a=78e5KktTucY:NEhGfeXaR1s:yIl2AUoC8zA"><img src="http://feeds.feedburner.com/~ff/CiscoIosHintsAndTricks?d=yIl2AUoC8zA" border="0"></img></a> <a href="http://feeds.feedburner.com/~ff/CiscoIosHintsAndTricks?a=78e5KktTucY:NEhGfeXaR1s:qj6IDK7rITs"><img src="http://feeds.feedburner.com/~ff/CiscoIosHintsAndTricks?d=qj6IDK7rITs" border="0"></img></a> <a href="http://feeds.feedburner.com/~ff/CiscoIosHintsAndTricks?a=78e5KktTucY:NEhGfeXaR1s:I9og5sOYxJI"><img src="http://feeds.feedburner.com/~ff/CiscoIosHintsAndTricks?d=I9og5sOYxJI" border="0"></img></a> <a href="http://feeds.feedburner.com/~ff/CiscoIosHintsAndTricks?a=78e5KktTucY:NEhGfeXaR1s:F7zBnMyn0Lo"><img src="http://feeds.feedburner.com/~ff/CiscoIosHintsAndTricks?i=78e5KktTucY:NEhGfeXaR1s:F7zBnMyn0Lo" border="0"></img></a> <a href="http://feeds.feedburner.com/~ff/CiscoIosHintsAndTricks?a=78e5KktTucY:NEhGfeXaR1s:V_sGLiPBpWU"><img src="http://feeds.feedburner.com/~ff/CiscoIosHintsAndTricks?i=78e5KktTucY:NEhGfeXaR1s:V_sGLiPBpWU" border="0"></img></a> <a href="http://feeds.feedburner.com/~ff/CiscoIosHintsAndTricks?a=78e5KktTucY:NEhGfeXaR1s:4cEx4HpKnUU"><img src="http://feeds.feedburner.com/~ff/CiscoIosHintsAndTricks?i=78e5KktTucY:NEhGfeXaR1s:4cEx4HpKnUU" border="0"></img></a> </div><img src="http://feeds.feedburner.com/~r/CiscoIosHintsAndTricks/~4/78e5KktTucY" height="1" width="1"/>Ivan Pepelnjakhttp://www.blogger.com/profile/13457151406311272386noreply@blogger.com7http://blog.ioshints.info/2011/12/thats-it-for-2011.html