There are however some rules to shorten it and it’s a way to remove zeros.

Rule 1: Suppress leading zeros

Remove all leading zeros, the left side zeros, in every 16 bits field.

For example:

2001:0db8:0000:0000:0000:0000:000:0001

will be simplified to

2001:db8:0:0:0:0:0:1

Of course 0000 becomes 0.

Rules 2: The larger sequence of :0:0: can be reduced to ::

You can compact a sequence of zeros to the symbol ::.

Applying the rule to 2001:db8:0:0:0:0:0:1 would get us 2001:db8::1.

• You can’t compact just one :0: – only a sequence.
• If there is more than one sequence of :0: you can only compact the large one. If they have the same length compact the first one.

2001:db8::1:1:1:1:1 is not correct. It must be 2001:db8:0:1:1:1:1:1.

2001:0:0:1:0:0:0:1 will become 2001:0:0:1::1.

2001:db8:0:0:1:0:0:1 will become 2001:db8::1:0:0:1.

That’s it.

I must create a simple script to check how many days are left and install it as a cron job.

After some search I found that curl and date could do it.

$ curl https://thejoyofstick.com -vI --stderr - | grep "expire date:" | cut -d: -f 2-
Jun 25 17:26:52 2022 GMT

$ date --date='Jun 25 17:26:52 2022 GMT' '+%s'
1656178012

$ date '+%s'
1649805603

$ echo '(1656178012-1649805603)/86400' | bc
73

We now have a way to calculate how many days are left.
You can build a bash script with these and, after checking for a countdown days threshold, send yourself a proper alert email.

For myself I’m using a perl script based on this one

#!/usr/bin/env perl

use strictures 2;
use IO::Socket::SSL;
use Net::SSLeay;
use Date::Simple ( 'date', 'today' );

my $site = shift || 'example.com';

my $client = IO::Socket::SSL->new("$site:443")
  or die "error=$!, ssl_error=$SSL_ERROR";
my $cert = $client->peer_certificate();
my $time = Net::SSLeay::X509_get_notAfter($cert);
my $asn_t = Net::SSLeay::P_ASN1_TIME_get_isotime($time);
my ($date) = split /T/, $asn_t;
my $diff = date($date) - today;
my $warning_time = 15;

print "Expire date: $date\n";
print "How many days left: $diff\n";
print "Warning before $warning_time days\n";

Added a personal email module to send a message if $diff is less than $warning_time and then cron with it.

Enjoy!

Where are the MIB files ?

I’m in the middle of upgrading old servers and I found Ubuntu starting on 12.04 didn’t install the MIB files. Even if you install the SNMP applications. It was really strange to launch tkmib and just see a couple of nodes.

The explanation is simple. Just check the preamble of /etc/snmp/snmp.conf

#
# As the snmp packages come without MIB files due to license reasons, loading
# of MIBs is disabled by default. If you added the MIBs you can reenable
# loaging them by commenting out the following line.
mibs :

Sure, but how can I install them ?

Fortunately there is a package to deal with that.

$ sudo apt-get install snmp-mibs-downloader

It will download the IETF MIB files and install them under the usual /usr/share/mibs/

If for any reason you don’t see it happen force it with

 $ sudo download-mibs

You can repeat this command later to update any new MIB file.

Let’s rock’n’roll

Well, almost. At this time your tools still won’t work correctly. Just remember the text on /etc/snmp/snmp.conf. You have to comment out the mibs : line! Now everything is by the book. Enjoy!

Install HP Support Software in your Ubuntu server

Reading package lists... Done                      
E: Repository 'http://dl.google.com/linux/chrome/deb stable Release' changed its 'Origin' value from 'Google, Inc.' to 'Google LLC'
N: This must be accepted explicitly before updates for this repository can be applied. See apt-secure(8) manpage for details.

The solution is fast. Just run

sudo apt update

Note that’s apt and not apt-get. And just accept the change.

Do you want to accept these changes and continue updating from this repository? [y/N]

Done!

Then just use again sudo apt-get update and sudo apt-get upgrade

The problem should be with me or my script as I knew it was all ok on some of the files.

However after bouncing my head several times I found the issue.

Some of the configuration has trailing spaces at the end of the line!

At first I thought it was may be a problem with RANCID. But it was not.

To make this visible I just issued something like this at the router prompt

sh run | b ^class-map match-any CORE-VOICE

And copy-pasted some lines to vim that gave me this

The red squares show that there are spaces at the end of two lines!

It’s a nice feature to have active on vim. Just add these two lines to your ~/.vimrc

highlight ExtraWhitespace ctermbg=red guibg=red
match ExtraWhitespace /\s\+$/

So, next time you have to chew some IOS-XR configurations files don’t forget to right trim all those lines!

In the Pike Place Market in Seattle, you can still find the first Starbucks. There’s something wrong with it, though. It’s not quite right, not quite a Starbucks . The logo is different; the layout is different.

 

It turns out that the original Starbucks didn’t sell coffee.

 

They sold coffee beans and tea leaves and even herbs. But except for a sip or a taste of coffee brewed from a particular bean (drip, no espresso!), there was no cup of coffee to be had.

 

Starbucks was wrong. Jerry Baldwin, one of the founders, made a mistake. He thought the beans were the point, not the coffee. Left to Jerry’s vision of the future, Starbucks would certainly have failed. It took Howard Schultz, a trip to Italy, and an obsession with espresso to turn Starbucks into Starbucks. And Howard gets a lot of credit for making that happen.

 

But what if the “wrong” Starbucks had never been built? What if Jerry and his partners had said, “Well, we’re not sure if this bean thing is going to work, so let’s do nothing”? Without Jerry Baldwin and his flawed idea for a coffee bean store, there’d be no Frappuccino. One led to the other by the usual route, which is never a straight line.

 

The original Starship Enterprise was conceived by Matt Jefferies. It looked like a cross between a Frisbee and a can opener. Clearly wrong.

 

But Matt had the drive to deliver. He took the wrong start and revised and improved and innovated until the Enterprise we know and love came to be. The hardest part, it seems to me, was the first one, the wrong one.

 

Poking doesn’t mean right. In means action.

 

As an example let’s connect to a Western Digital My Cloud that has the default name WDMyCloud.

How to mount it

After launching the Finder you may see it at the Shared section

and just click it and connect with the share you want.

If it’s not visible just select from the Finder’s Menu Go / Connect to Server...

At the Server Address: type

cifs://wdmycloud.local

You may change wdmycloud.local with the IP address of your NAS or remote share. Choose the type of connection and then just choose a share. It will show up like this

Auto mounting the share

Select from the top menu Apple / System Preferences... / Users & Groups / Login Items

Click the + button and now select your remote device from the left list under Shared.

Make the connection and select the share you want.

It’s done! Now every time you enter your Mac it will try to mount that share immediately.

A little note…

Apple guys like to be funny. See what would show up if you used smb: instead of cifs:

You may be interested in Using an SMB share from Mac OS X in Linux

RewriteEngine On
RewriteBase /blog/
RewriteRule ^index\.php$ - [L]
RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FILENAME} !-d
RewriteRule . /blog/index.php [L]

There are two reasons for this to happen. The mod_rewrite is not enabled by default and your configuration may not allow the use of .htaccess

Enabling mod_rewrite

As I usually don’t mess with Apache I often forget it has a command to enable modules. It’s just like this.

sudo a2enmod rewrite

Enabling .htaccess files

Edit your site configuration file under /etc/apache2/sites-available/. At the Directory entry for your site files you need to allow the reading of directives in .htaccess files.

If you were editing the default site

        
                Options Indexes FollowSymLinks MultiViews
                AllowOverride None
                Order allow,deny
                allow from all
        

you would have to use AllowOverride FileInfo or even AllowOverride All. It’s your choice.

Get it to work

Finally you have to restart the Apache server to activate the changes

sudo service apache2 restart

That’s it!

I’m assuming you only want IPv4 :-)

The straightforward solution is just to disable IPv6 on your machine.

How to disable ipv6 in MacOS X

If you have Leopard or Snow Leopard (10.5 or 10.6) click Apple / System Preferences / Network. Choose Ethernet or Airport and then Advanced / TCP/IP. Choose off on Configure IPv6.

For Lion or Mountain Lion (10.7 or 10.8) first open a Terminal. To know the name of the network interface you want to edit type

$ networksetup -listallnetworkservices

And then disable IPv6 like this, for example,

$ networksetup -setv6off Wi-Fi

Want to get back ?

$ networksetup -setv6automatic Wi-Fi

How to disable IPv6 in Linux

Let’s suppose you were using WiFi

$ ifconfig wlan0
wlan0     Link encap:Ethernet  HWaddr 00:1e:65:f6:84:f4  
          inet addr:192.168.1.9  Bcast:192.168.1.255  Mask:255.255.255.0
          inet6 addr: fe80::21e:65ff:fef6:84f4/64 Scope:Link
          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
          RX packets:34340 errors:0 dropped:0 overruns:0 frame:0
          TX packets:29814 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:1000 
          RX bytes:25657649 (25.6 MB)  TX bytes:7569224 (7.5 MB)

You can see your interface also is using IPv6.

$  sudo sysctl net.ipv6.conf.wlan0.disable_ipv6=1
[sudo] password for biafra: 
net.ipv6.conf.wlan0.disable_ipv6 = 1

$ ifconfig wlan0
wlan0     Link encap:Ethernet  HWaddr 00:1e:65:f6:84:f4  
          inet addr:192.168.1.9  Bcast:192.168.1.255  Mask:255.255.255.0
          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
          RX packets:34507 errors:0 dropped:0 overruns:0 frame:0
          TX packets:29977 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:1000 
          RX bytes:25677902 (25.6 MB)  TX bytes:7597685 (7.5 MB)

You can disable it between reboots on /etc/sysctl.conf with this line:

net.ipv6.conf.wlan0.disable_ipv6 = 1

The network problems continue

Really ? Then maybe it’s not an IPv6 issue! :-)

Preparation

Start connecting a Cisco console cable (cross over cable) from the console port of the router (routerc) to the auxiliary port of the helpful router (routerh).

After remotely accessing routerh configure it’s aux line

routerh#conf t
Enter configuration commands, one per line.  End with CNTL/Z.
routerh(config)#line aux 0
routerh(config-line)# transport input telnet
routerh(config-line)#^Z
routerh#

Using the console

We need to know the line number of the AUX port and the IP address of this routerh

routerh#sh line
   Tty Typ     Tx/Rx    A Modem  Roty AccO AccI   Uses   Noise  Overruns   Int
      0 CTY              -    -      -    -    -      0       0     0/0       -
      1 AUX   9600/9600  -    -      -    -    -     13      21     0/0       -
*     2 VTY              -    -      -    -    5    202       0     0/0       -
      3 VTY              -    -      -    -    5      1       0     0/0       -
      4 VTY              -    -      -    -    5   4358       0     0/0       -
      5 VTY              -    -      -    -    5    125       0     0/0       -
      6 VTY              -    -      -    -    5      1       0     0/0       -

routerh#

It shows the aux port is on line 1. Our IP address is 192.168.1.1

To access the console you have to telnet your local IP address at port 2000 plus the line number:

routerh#telnet 192.168.1.1 2001
Trying 192.168.1.1, 2001 ... Open

routerh line 1 


User Access Verification

Username: biafra
Password: 
[ENTER]

routerc line 1 


User Access Verification

Username: biafra
Password: 

routerc#

And you are now using the console of routerc. Please note that you may have no console access restrictions as it’s shown here because of AAA.

Suspending and Disconnecting

You can get back to routerh with ctrl-6 x (or ctrl-shift-6 x).

routerh#sh users
    Line       User       Host(s)              Idle       Location
   1 aux 0     biafra     idle                 00:00:13 192.168.1.1
*  2 vty 0     biafra     192.168.1.1          00:00:09 10.0.0.10

  Interface    User               Mode         Idle     Peer Address

routerh#

Just hitting enter or entering the session number you are connected again to the remote console.

To disconnect just check the aux line with sh users and

routerh#clear line 1
[confirm]
 [OK]
routerh#
[Resuming connection 1 to 192.168.1.1 ... ]

[Connection to 192.168.1.1 closed by foreign host]
routerh#

routerh#sh users
    Line       User       Host(s)              Idle       Location
*  2 vty 0     biafra     192.168.1.1          00:00:14 10.0.0.10

  Interface    User               Mode         Idle     Peer Address

routerh#

To remember

Configure the aux port and suspend the console with ctrl-6 x.