Tips & tricks

wireshark ssh remote connect on linux server

2020-10-07T01:38:00.006+02:00

First, install the optional component from Tools section of Wireshark installer

Then, select config gear of the SSH remote capture from the welcome screen

Configure the following information:

Server ip/hostname and port

Remote user name and private rsa key in OpenSSH format (use puttygen > conversions > export openssh key)

(user and password should work too)

You shouldn't have to change anything in Capture tab

If you get an error linked to Kex algos:

Error by extcap pipe:

** (sshdump.exe:8216): WARNING **: Error creating connection.

** (sshdump.exe:8216): WARNING **: Connection error: kex error : no match for method kex algos: server [curve25519-sha256,curve25519-sha256@libssh.org,ecdh-sha2-nistp256,ecdh-sha2-nistp384,ecdh-sha2-nistp521,diffie-hellman-group-exchange-sha256,diffie-hellman-group16-sha512,diffie-hellman-group18-sha512,diffie-hellman-group14-sha256], client [diffie-hellman-group14-sha1,diffie-hellman-group1-sha1]

You have to add the requested algorithms to the server or client.

I've handled it adding this line to /etc/ssh/sshd_config on the server:

KexAlgorithms +diffie-hellman-group1-sha1

Then reload the ssh server

ubuntu 20.04 / netplan / change mac address and static ip

2020-08-11T22:28:00.004+02:00

I wasn't able to set together a virtual mac address and a static IP using netplan: either the mac address didn't change, or IP was not set.
I finally got the trick using a fake nic definition that matches the new virtual mac address I've set.

network:
renderer: networkd
ethernets:
    ens160:
      match:
        macaddress: 00:0c:29:5a:69:00
      macaddress: 00:50:56:0c:de:a6
    ens160_2:
      match:
        macaddress: 00:50:56:0c:de:a6
      addresses: [ 139.99.5.72/32 ]
      nameservers:
        addresses: [ 8.8.8.8 ]
      routes:
      - to: 0.0.0.0/0
        via: 139.99.5.254
        on-link: true
    ens192:
      addresses: [192.168.103.14/24]
      #dhcp4: true
version: 2

rpi ubuntu 18.04 arm64 - fix bluetooth not working

2019-03-25T22:40:00.004+01:00

apt install bluez
hciattach /dev/ttyAMA0 bcm43xx 921600
systemctl restart bluetooth

Run AspNet Core 2.2 on Raspberry PI 64bits (ubuntu 18.04 arm64)

2019-03-14T00:20:00.000+01:00

As Ubuntu does officially support Raspberry PI 3 (arm64 and armhf) starting with 18.04.2, I gave a try to the 64 bit version to be able using dotnet core with MongoDB as the later is discontinued in 32 bits architecture.

I've downloaded and extracted the 32bits version of aspnet core as the arm64 is not yet supported.
But I've quickly found myself ending with an issue when trying to run the armhf dotnet app:

-bash: /opt/dotnet/dotnet: No such file or directory

Even if all the dotnet prerequisites were met.

A few Googling hours later, I've figured out that, by default, no 32 bits (armhf) libraries are installed.

Thought that can be done simply.
First allow the armhf repository to be used in addition of arm64:

dpkg --add-architecture armhf

apt update

Then add the armhf flavor of the dotnet prerequisites:

apt install libunwind8:armhf gettext:armhf libc6:armhf libssl1.0-dev:armhf

You can now enjoy running aspnet core 2.2 apps on a arm64 ubuntu 18.04 :-)

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Install node.js and java package on raspbian (raspberry pi)

2019-01-22T18:03:00.001+01:00

apt install openjdk-8-jdk
apt install nodejs
ln -s /usr/lib/jvm/java-8-openjdk-armhf/jre/lib/arm/client/libjvm.so

Fix broken LibreElec on Raspberry Pi after auto-update (could not mount /flash/SYSTEM)

2017-05-30T00:19:00.001+02:00

Mount the SD card on Windows or Linux.
Grab the latest LibreElec image file from https://libreelec.tv/downloads/
Extract the kernel.img and the SYSTEM files from the downloaded file.
Replace the existing kernel.img and SYSTEM files on the SD card with those two files.

Put back the SD card in the RPi and all should be fine.

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Zabbix : use external ip in simple checks

2017-05-19T12:45:00.000+02:00

In Zabbix, simple checks are done by the Zabbix Server or Proxy on the default agent IP address, usually the internal one.
If you would like to monitor some services like SSH or SMTP using the external IP address, simply add another Agent Interface with the external IP.

Then choose the external interface in the item configuration:

Shortcut to open the focused Window's menu when Launchy has been registered to ALT+SPACE hotkey

2017-03-17T12:02:00.001+01:00

Simply press WINDOWS KEY+ALT+SPACE

:-)

Resolve "Cannot download packages whilst offline" issue in Deja-Dup backup software

2017-02-03T16:06:00.002+01:00

If you got the error message "Cannot download packages whilst offline" but your internet connection is active, this is probably because you've managed the network configuration yourself and the network manager is reporting an offline status even if it's not correct.

To fix this issue, simply edit the file /etc/NetworkManager/NetworkManager.conf and change the following configuration to be inline with:

[ifupdown]
managed=true

Then restart the Network Manager :

sudo service NetworkManager restart

Using TeamViewer on headless (without monitor) ubuntu machine

2017-01-13T16:02:00.001+01:00

In order to get TeamViewer running smoothly (without lag, or simply cannot install) when no monitors are connected, you need to emulate one.

This is done by creating (or editing) this file :

/usr/share/X11/xorg.conf.d/xorg.conf

And add the following content :

Section "Device"
    Identifier  "Configured Video Device"
    Driver      "dummy"
EndSection

Section "Monitor"
    Identifier  "Configured Monitor"
    HorizSync 31.5-48.5
    VertRefresh 50-70
EndSection

Section "Screen"
    Identifier  "Default Screen"
    Monitor     "Configured Monitor"
    Device      "Configured Video Device"
    DefaultDepth 24
    SubSection "Display"
    Depth 24
    Modes "1024x800"
    EndSubSection
EndSection

Reboot the computer

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Windows 10 Pro English UI : Fix the keyboard layout always switching to UK/US when it has been set to Belgian French

2016-06-15T10:32:00.003+02:00

Simply install the french language pack, even if it's not set as the OS's UI language:

How to send large backup on Hubic using Synology Hyper Backup when you get connection issues for the first synchronization

2016-06-15T10:16:00.002+02:00

In your backup task, simply drill down in the folder tree to select only a few folders amongst the whole set of folders you would like to backup in order to keep the backup size and time reasonable.

When the backup task succeeds, edit the task and add a few folders more.

Then relaunch the backup task.

The Synology Hyper Backup service will only backup the freshly added folders and data that has changed from the last succeeded backup task.

Reapeat that operation untill all the folders are backuped.

Workaround for tp-link tl-wa854re Access Point wifi extender network issue

2015-12-13T22:54:00.001+01:00

For an unknown reason, my tp-link Wifi extender has suddenly stopped working.

In fact, it didn't find anymore the DHCP server, even connected to the root Wireless network.

In the network interface of a device connected to the AP I saw the following parameters obviously set by the AP as this was not in my home network range:

DHCP server : 192.168.0.254
DNS server : 192.168.0.254
Gateway : 192.168.0.254

So I've simply entered this ip address in a browser from a client device of the AP, using admin/admin as user and password and set a static ip address to the AP (in Network > LAN) and disabled the embedded DHCP server (in Network > DHCP settings).

Can't connect to VMWare Server using vSphere client

2015-11-13T11:09:00.000+01:00

If you are not able to connect to your VMWare Server using the vSphere client but you are sure that the VMWare server is up and running, try this :

If you have enabled the ssh service connect to the SSH console of the server and type :

services.sh restart

This will restart the services without stopping the virtual machines

Use Internet Explorer on Windows 10

2015-11-12T23:27:00.001+01:00

Simply launch the Execute dialog hitting the Windows + R keys at the same time and type:

iexplore

Then click on OK or push on ENTER

c# : programatically disable IIS AppPool Recycling

2015-08-28T11:49:00.001+02:00

using System;

using System.Text;

using Microsoft.Web.Administration;

using System.Linq;

internal static class Sample

{

private static void Main(string[] args)

{

using (ServerManager serverManager = new ServerManager())

{

foreach (var ap in serverManager.ApplicationPools)

{

ap.Recycling.PeriodicRestart.Time = TimeSpan.Zero;

}

serverManager.CommitChanges();

}

Get access on your synology nas having ssh disabled without reset when you cannot bypass the Two-Factor Authentication

2015-07-30T01:28:00.000+02:00

Few days ago, I couldn't connect to my synology backup NAS because I've reset my phone and therefore lost my Google Authenticator's data.
When I've tried to click the "Lost my phone" link, I got a message :

you have exceeded your emergency code limit

As this is a backup NAS, I've enabled only few services, i.e. not SSH.
And there is only one administrator account on this NAS.

I didn't wanted to reset my NAS and reconfigure all parameters.

Hopefully for me, rsync was enabled and I had another nas available with 2FA enabled also. So I've simply overriden the google_authenticator file using rsync.
That also lets me now to connect to my both NAS using the same code :)

Here is the command line :

rsync -avzh /usr/syno/etc/preference/admin/google_authenticator root@192.168.1.2:/usr/syno/etc/preference/admin/

192.168.1.2 is the ip address of the NAS I wanted to get access
you have to use 'root' user, not 'admin'. And the password is the one set for 'admin' user

You can also simply get the google_authenticator file on your local computer using rsync the same way :

rsync -avzh root@192.168.1.2:/usr/syno/etc/preference/admin/google_authenticator .

You can then manually add an account in Google Authenticator.

If you want to delete the file on the NAS in order to be able to connect without 2FA:

download the whole directory (/usr/syno/etc/preference/admin/) on your local computer using rsync
delete the google_authenticator file on your local computer
upload the directory back on the server using the flag --delete on rsync

Allow ALT+CTRL+DEL on Windows Logon Screen with LogMeIn on servers protected by Eset File Security

2015-07-13T22:52:00.003+02:00

The HIPS module does not allow LogMeIn to use ALT+CTRL+DEL on the Windows Logon Screen on the server version of Eset Antivirus (called Eset File Security).

You may simply disable the HIPS functionality but that requires a server reboot and that let your server with a weaker protection. Or you can follow those steps :

VPN site to site between Sophos and Watchguard : error ignoring informational payload, type INVALID_EXCHANGE_TYPE

2015-06-29T17:31:00.000+02:00

On the watchguard firewall, check that the Gateway Phase 1 mode is set to "Main" and not "Aggressive" :

Resolve bad gateway error on nginx configured as reverse proxy with HTTPs support (front and back end)

2015-06-12T15:33:00.000+02:00

If you get the message "502 Bad Gateway" from your nginx reverse proxy but you've checked that your IIS server is reachable and the website is working fine, check that at least one of the websites binded on IIS with HTTPS support is NOT configured with SNI, even if this is not one website that should be accessible from your proxy.

Long story short : the following command should return SSL certificate information, even if it is not from the certificate you expect to get in order to get nginx connection to IIS to work:

openssl s_client -connect myserver.mynetwork.local:443

Add a new tap adapter for OpenVPN on Windows 8.1 to allow multiple connections

2015-05-16T14:54:00.000+02:00

Simply run the utility located at

"C:\Program Files\TAP-Windows\bin\addtap.bat"

as administrator

Connect the Xiaomi Yi Ants Cam to your Synology Surveillance Station

2015-03-29T21:29:00.003+02:00

1) Ensure the current firmware of your cam allows you to see the steam without authentication.
You can check this using vlc and connecting to

rtsp://192.168.1.128:554/ch0_0.h264

If you are able to see the stream, you can go to the next point. Otherwise you have to downgrade the firmware of your cam :
Simply place this file on the root of an SD card, insert the SD card in the cam and reset it (a reboot may be sufficient)

2) Create the following file on your synology using putty /volumeX/@appstore/SurveillanceStation/device_pack/camera_support/Xiaomi.conf
with this content:

[Xiaomi*Ants]
api = custom
resolution_h264 = 1280x720
default_resolution_h264 = 1280x720
fps_h264_640x480 = 5,10,15,20,25,30
fps_h264_1280x720 = 5,10,15,20,25,30
default_fps_h264_1280x720 = 10
default_image-quality = 5

h264 = rtsp
mpeg4 = rtsp
mjpeg = rtsp
motion = h264,mpeg4,mjpeg

motion_param = sensitivity,threshold
rtsp_keepalive = none
rtsp_protocol = auto,udp,tcp

3) In the surveillance station, add the new Xiaomi Ants camera, using the ip of your cam and port 554

4) Export the configuration

5) Edit the exported configuration using putty or the Text Editor in your File Station :
Browse where you saved the configuration, search the file ".ExpCam" and edit "path" and "live_path" parameters like this:

path = '/ch0_0.h264'
live_path = '/ch0_0.h264'

6) Delete the camera in the Surveillance Station

7) Import back the configuration

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Synology : Fix double-factor authentication issue linked to time desynchronization

2015-03-03T15:37:00.002+01:00

It could be linked to the fact that your synology is not time-synchronized anymore.

Connect through ssh and execute the following command :

ntpdate -u pool.ntp.org

the -u switch allow to use another port if the ntp deamon is already running.

Install Russian or French Languages in Xiaomi Redmi 2 (Or other EU languages)

2015-02-20T11:48:00.000+01:00

On my Xiaomi Redmi 2 bought on TinyDeal, the only available stock languages were Chinese and English.
But I wanted to switch to Russian or French language.

Sadly, there is no possibility to install a single package for the language you want (at least I didn't find any information about it)
But you can find some ROMs including multi-languages support.
The only drawback is that the only ROM working I've found does not come with the latest version of MIUI but that's not a big deal.

You can download the ROM HERE.
Install it using the Updater application (can be found in the settings > About > Update)
Screenshots and procedure to install can be found HERE

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Install Google Play Store and Google applications on Xiaomi Redmi 2

2015-02-20T11:46:00.001+01:00

Some users told it's possible to download an application called "Google Installer" from the Xiaomi's Mi Market, but I was unable to find it.
Downloading the Play Store APK directly wasn't better.

Hopefully I've found the APK of the Google Installer HERE and from this package I was able to install the Play Store and my favourite applications.

BACKUP LINK

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