Earlier today I was needing to verify two pieces of configured equipment were using the correct 802.q trunks by using a packet capture. Continue reading “Mirroring 802.1q trunk interfaces while preserving the tags”
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 “Mercurial for Tracking Cisco Configs”
I worked recently to add a Calix E7 to a network to do GPON Fiber for Ethernet customers. The customers would need to get a dhcp address for a dhcp server, and I needed to add DHCP Option 82 logging for record keeping purposes. Continue reading “Using an ASR9000 with Calix E7 gear”
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 “Allowing UNI or protected ports on Cisco switch to reach each other using IP”
Sometimes I find a need to use a console cable remotely, but getting someone to set up a PC or laptop with a serial connection for remote access can be quite a hassle. I have used the following configurations to get remote serial access using only an onsite router. Continue reading “Using reverse telnet and ssh”
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.
Continue reading “Editing Cisco ACLs Inline”
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 “Setting up 802.q and switch ports in an ASR9000”
After not having time to write an article for a while, here is the article I promised in the last post. We will take our basic network from our other article on source based routing, and expand it. This solution involves a dual-homed network with redundant gateways. Continue reading “Source Based Routing for Multiple Networks”
When you are transitioning from one carrier to another using provider allocated IP space there is a neat little trick you can use to route outbound traffic through the correct carrier. While there are some carrier’s that do not filter their ingress traffic, there are many others who do.
Continue reading “Source Based Routing with Cisco”
I’ve been working with a lot of PPPoE deployments in the past few weeks, and decided to post a short template of the Cisco side of things. Note that I will not be blogging on how to set up a radius server in this post or how to set up the AV-Pairs to rate-limit etc…