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Linux Networking Systems Administration

Notes from debugging OSPF between cisco devices and Linux FRR ospfd configs

When trying to find why my ospf configs were not sending the correct costing from Linux -> Cisco devices, I found some useful commands that I thought I would note down for future reference. Linux – Using vtysh My ospfd.conf looks something like this: You can see the costs on linux using the vtysh command: […]

Categories
Linux Networking Systems Administration

Workaround for SSH error to Cisco switch from Ubuntu 20.04 – no matching key exchange method found

Trying to SSH to a Cisco switch from Ubuntu 20.04 you may get this error: This error is because Ubuntu 20.04 has disabled the SHA1-based key exchange methods after some attacks have been found on SHA1. To work around this issue for Cisco switches you can use the command line argument -oKexAlgorithms=+diffie-hellman-group1-sha1 like this: To […]

Categories
Linux Networking Systems Administration

A script to connect to a Cisco switch and backup the running-config using Python3 and Paramiko

I have been trying to find a way to create a regular backup of my Cisco switch’s running-config, so I can store it in my normal backups. However, after searching online I was able to find some tools that were almost there, but nothing that was quite as flexible as I needed, so I wrote […]