Catalyst

Using Probes on the CSM

·4 min read

There are three different ways that a CSM checks for the health of the servers – active probes, inband health checking, and inband HTTP monitoring. Let’s talk about active probes. Active …

Using MAC Access-lists

·3 min read

We ran into this today, and, though I knew it existed, I never actually saw it in the wild. I’m talking about MAC access-lists. In the example setup, we have a DMZ off of a firewall that …

Configuring Fault Tolerance on the CSM

·4 min read

Like (nearly) everything in the Cisco world, you can set up your CSM to fail over to another module when the primary dies a horrible death. You can have two in the same chassis or even have them in …

Storm Control

·4 min read

We run a large number of LANs all over the country that are “controlled” by the particular business unit. We manage the gear, but, since they have the money and have to pay for anything we …

Getting Started with EtherChannel

·3 min read

In my professional life at some point, I came across someone who had a stack of Catalyst 2950 switches all trunked together with their Internet routers connected to the top of the stack. This was all …

Trunking on a Catalyst Switch

·3 min read

If you didn’t now already, trunks are connections between switches that carry traffic for all VLANs. It allows you to have, say, VLAN 10 and VLAN 20 on two switches appear as the same network. …