More IIUC notes.  As always, feel free to correct as needed.

To match inbound calls to a dial peer, CME (and CUCM?) uses the following steps.

1. Match DNIS (the dialed number) with the incoming called-address config in the dial peer
2. Match the ANI (the calling number or caller ID) with the answer-address config in the dial peer
3. Match the ANI with the destination-pattern config in the dial peer
4. Match an incoming POTS call to the port config in the dial peer
5. Match dial peer 0

Matching dial peer 0 is bad, and it took me an inquiry on Twitter and a buddy to realize why.  Here are a few highlights as to why.  I believe the full scope of the badness of dial peer 0 is really beyond the IIUC exam.

As always, feel free to correct anything that needs correcting or add anything that needs adding.  There is a lot more to the full definition of wildcards, but these are the basics.  Note to *nix guys:  This isn’t regex as you understand it.  Yes, the use of curly braces would be nice, but we don’t get that here.

T:  Represents anywhere from 0 to 32 digits

destination-patter 9T  <- matches a 9 followed by 0 - 32 other digits

Here are some packet overhead numbers for a few popular protocols to help with doing bandwidth requirement calculations.  This may be another add-as-we-go post, so please comment with additions or corrections.

Ethernet : 20 bytes
Frame Relay : 4 - 6 bytes
PPP : 6 bytes
MLPPP: 10 bytes
MPLS : 4 bytes

IP : 20 bytes

TCP : 20+ bytes
UDP : 8 bytes
GRE:  4 - 20+ bytes

Remember a few weeks back when I had a bad day?  I was actually at HQ that day to do some work for a project, but that got put off due to the extenuating circumstances.  When we finally got back around to do the work, we wound up adding a switch in the data center to extend a VLAN over to a rack.

How did 2010 turn out?  Not as well as I would have liked.

We’re an Avaya voice shop (for now if I have my way) and have Avaya systems of various sizes and shapes all around the Enterprise.  I was at one of our remote locations a few weeks back and helped the guys there replace a non-PoE switch so they could get the old power injector panel out of their rack.  When we moved stuff around, the phones didn’t come back and had the dreaded DHCP Ack Error.

EIGRP allows you to tag external routes.  That is, any route redistributed into EIGRP can be tagged with a numeric descriptor from 0 to 4294967295.

It looks like Cisco is trying to crack down on illegal distribution of their software.  I can’t really blame them since it’s their property.

I was exploring commands on the ASA a while back and discovered that you can run commands on the standby unit from the active.

A buddy asked for some help on configuring a pair of ASAs in active/passive mode, and, by pure coincidence, my newest project is to set up the same.  I’ve done it many time, but it’s one of those things that you don’t really do every day (unless you’re a VAR or something).  These things always get covered in rust very quickly in my head, but, once I get one or two details back to the surface, it all comes flooding back. I better take the time to jot down the details.