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”
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 “Allowing UNI or protected ports on Cisco switch to reach each other using IP”
Using reverse telnet and ssh
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”
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.
Continue reading “Editing Cisco ACLs Inline”