Author Archives: Brian Christopher Raaen

Mercurial for Tracking Cisco Configs

As I have been working with different routers I have squired a small repository of configuration files that I use for examples, backups, and ways of remembering the way the network was set up before a change. At the start I maintained each config as a separate file, usually containing the date (i.e. router1-071012.cfg). While that worked for a while it got cumbersome when I wanted to track more than one legacy version of a config file. Continue reading

Allowing UNI or protected ports on Cisco switch to reach each other using IP

When deploying Metro Ethernet service and Colocated services, best practice it to put the ports in protected mode or uni. This is to prevent customers from causing interference to each other with layer2 protocols. It also allows the user of service provider traffic filtering. The downside is without additional configuration, customer traffic to another customer is blackholed when they exist in the same subnet. Continue reading

Editing Cisco ACLs Inline

Are you annoyed at having to copy an ACL to a text editor to add a line?   After that, you have to either remove the ACL entirely or add the new version with a different name and update all the interfaces to use the new name.  I have been using the following trick recently to edit ACLs inline without having the complete remove or rewrite the ACL.
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Setting up 802.q and switch ports in an ASR9000

IOS-XR has a structure that is very different than standard IOS. I would recomend checking the different documentation at Cisco.com this post is not going to explain things like having to commit a config before it is applied… etc, but rather I am going to assume you have read the getting started guide.

The project that lead to me being exposed to an ASR9000 is a network migration that is replacing a pair of 7200 routers and a 3750 switch (which is only being used for layer2 features) with a single ASR9000 with Redundant RSPs. The ASR has a 40 port gig module and a 4 port 10 gig module. To replace the switch I need to add ports to a “vlan” and trunk those vlans to downstream switches at other pops. Continue reading

Formating Mac addresses using python

I have a large set of shell script that I had written in shell, which I have been converting to python based scripts.  I found using python I could better extend my scripts and reuse code.  I also appreciate that python is a full object oriented programming language, with a very powerful set of standard libraries and many optional third party libraries.
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