Cisco FlexLink Configuration Examples
Here you can find some configuration examples for the Cisco Flexlink. This example shows how to configure an interface with a backup interface and to verify the configuration: Switch# configure...
View ArticleBug in Cisco Catalyst 2960S
I found a new bug in the IOS 12.2(55) on our c2960s where we had a high cpu usage and lot of traceback syslog messages. Here is the info from the Cisco TAC about the problem: Symptom: C2960S switch...
View ArticleCisco Catalyst SPAN and Remote SPAN Configuration
To analyze network traffic passing through ports or VLANs you can configure SPAN or remote SPAN to mirror the traffic to another port on the switch or on another switch that has been connected to a...
View ArticleCisco Catalyst static CAM table entries
That’s maybe not interesting for everybody but when you use Windows Network Load Balancing in your network you should definitively configure static CAM table entries otherwise your VLAN will be flood...
View ArticleCisco ASA EtherChannel Interfaces
With the ASA version 8.4 Cisco introduced port-channels (ASA5510 or higher) what is a really nice feature because you can share the load over more interfaces. When it comes to a physical interface the...
View ArticleAnsible Interface Playbook (ios_config): Cisco interface config
Here an Ansible Playbook with three different examples how to configure Cisco router interfaces: 1. Static IP address configuration in playbook 2. Configuration comes out of Jinja2 template, can be run...
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Data centre network redesign
Over the last month I was busy working on an data centre redesign for my company which I finished this weekend in one of the three data centre’s. The old network design was very outdated and bad choice...
View ArticleCumulus Networks (Open Networking)
In my recent data centre network redesign project I used Cumulus Linux on Open Networking switches from Dell (S3048-ON and S4048-ON). I heard from Cumulus Networks around 2 1/2 years ago and did some...
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Ansible Playbook for Cumulus Linux (Layer 3 Fabric)
Like promised, here a basic Ansible Playbook for a Cumulus Linux Layer 3 Fabric running BGP which you see in large scale data centre deployments. You push the layer 2 network as close as possible to...
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New Cumulus Linux leaf-switches
Just added another pair of Cumulus Linux leaf (top of rack) switches and more VMware compute nodes to our production system. We use a Layer 2 network fabric, see my recent post about an example:...
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Cumulus Networks NetQ telemetry-based validation system
I had some time to play around with the new NetQ tool from Cumulus which checks your Cumulus Linux switch fabric. I did some testing with my Cumulus Layer 2 Fabric example: Ansible Playbook for Cumulus...
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Cumulus Linux Lab using Vagrant
I was using GNS3 for quite some time but it was not very flexible if you quickly wanted to test something and even more complicated if you used a different computer or shared your projects. I spend...
View ArticleCumulus Linux non-disruptive upgrade procedure on MLAG pairs
I thought it would be useful to know the exact procedure for non-disruptive upgrade on Cumulus Linux MLAG – CLAG pairs. I find the online documentation Upgrading Cumulus Linux a bit short when it comes...
View ArticleCumulus Linux Ethernet link-state monitoring using ifplugd
This blog post is about link-state monitoring under Cumulus Linux. Cumulus has no own builtin tool for this and recommends using ifplugd. The tool has some similarities to Cisco’s IP SLA which can...
View ArticleCumulus Linux Snapshot Rollback
After my first post about Cumulus Linux non-disruptive upgrade procedure on MLAG pairs here the rollback procedure which is good to know in case you need to revert a snapshot after an unsuccessful...
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Ansible Playbook for Arista vEOS BGP IP-Fabric
Over the Christmas holidays, I was working just for fun on an Arista vEOS Vagrant topology and Ansible Playbook. I reused my Ansible Playbook from my previous post about an Ansible Playbook for Cumulus...
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BGP EVPN and VXLAN with Cumulus Linux
I did some updates on my Cumulus Linux Vagrant topology and added new functions to my post about an Ansible Playbook for the Cumulus Linux BGP IP-Fabric. To the Vagrant topology, I added 6x servers and...
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