I was doing an HSRP lab the other day, and a project from the past popped into my head. A customer had a host on a network that was separated from the rest of the network by a 1700 with a couple of …
Have I talked about the Cisco Firewall Services Module (FWSM) before? It’s a firewall on a module for the 6500 and is based on the PIX firewall. The term “based on” is important …
In my billion years in the industry, when I’ve asked for network diagrams, I’ve inevitably received a physical diagram – a diagram that shows where stuff is plugged in. This is fine …
Here’s a scenario I ran into long ago. We had several sites that had a frame relay link back to headquarters and a DSL line. Each link was terminated into a different router on a flat LAN with …
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 …
If you’re running iBGP, you may have run across this. What if you had three routers – R0, R1, R2 – that were running BGP under the same ASN, but R1 and R2 weren’t peered? Any …
VLAN Trunk Protocol (VTP) is a little gem on Cisco switches that allows you configure VLANs in one place and have them appear on all of your switches. This is great for large enterprises with 8457839 …
A lot of IOS commands give you a lot of information. Most of the time, though, it’s way too much information, and it sure would be nice to do some grep-like stuff on the output, right? Well, …
I realized the other day that I haven’t mentioned EIGRP once. As a Cisco guy, I think I’m required to do at least one article on it, so here it goes. Enhanced Interior Gateway Routing …
We just talked about tagging traffic and policing traffic, but we haven’t talked about prioritizing traffic. Tagging just sets a value in the header. Policing sets a “bandwidth …