Categories
Linux Systems Administration

A tool to take Cisco Umbrella logs and output them to Syslog messages

I wrote a tool recently that allows taking log files from the Cisco-managed S3 bucket, and outputs each log line as a Syslog message, with the content of the log line as a JSON-formatted message. Details of the Cisco-managed S3 bucket are here: https://docs.umbrella.com/deployment-umbrella/docs/cisco-managed-s3-bucket Once logged onto disk, the output of this tool looks like: […]

Categories
Networking

Learn OSPF with Darrell Root’s OSPF tutorial videos

When trying to debug OSPF issues recently I found a set of excellent video tutorials from Darrell Root: https://www.youtube.com/c/DarrellRoot – I believe this is his website: https://networkmom.net/CiscoHandsOnTraining/ He has a playlist of videos called Cisco Hands-On Training: https://www.youtube.com/playlist?list=PLueKg14298FzreJSTGtMFIGdu10GLnT6z I found his videos super helpful, and a very clear explanation of how OSPF works, and how […]

Categories
Linux Networking Systems Administration

A script to bring Cisco Switch VLAN data into phpIPAM

We have recently set up an IPAM at my workplace, the excellent phpIPAM – https://phpipam.net/ I went through our install and added all our subnets into the IPAM, but to make the data much more useful we wanted to have the VLAN information also: However, I didn’t want to go through by hand, adding each […]

Categories
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 or Redhat 8 – no matching key exchange method found

Trying to SSH to a Cisco switch from Ubuntu 20.04 you may get this error. I’ve noticed the same thing from Redhat RHEL 8: 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 […]

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 […]