Kevin Dorrell, CCIE #20765

24 Apr 2008

Background process

Filed under: General — dorreke @ 15:39

I’ve not blogged for a few days, so I thought I had better do so, even if only to set something on the record. Actually, I have written some journal, but for one reason or another I had to mark the entries as “Private”.  Sorry guys!  I do this blog as much to keep my own journal as for the benefit of others.

NMC Lab 17 

It’s week 17, and I should be doing NMC Lab 17. Unfortunately, as I was preparing my file for the week I caught sight of some of my old notes from the first time I did this lab, which kind of spoilt it. There are three features of Lab 17 that I might have stumbled over, but now I have seen the solutions I shall have to do it as an exercise in speed rather than in puzzle solving.

Cryptically, so as not to spoil it for anyone else, the stumbling blocks would have been:

  • 17.1.4 – how to arrange the FR topology
  • 17.8.6 – how to decide which router in AS 10 is the route reflector
  • 17.8.12 – how to arrange the filtering without looking at the prefixes or the AS-PATH

EIGRP Troubleshooting

I have been watching the NetWorkers OnLine presentation about EIGRP troubleshooting, and very good it is too.  NWOL is excellent all round.  Fortunately, I get it included in the price of my attendance at Barcelona back in January, but you can subscribe even if you didn’t go to the live event.  I can thoroughly recommend it.

One trick I learned is ping  I hadn’t realised that would provoke a response from every potential EIGRP neighbor.  This is a good way of quickly finding out whether a neighbor is listening to the EIGRP multicast, even if it has not yet successfully set up a neighbor relationship.  I am still looking into this: for example, I want to find out what happens if the neighbor has a static neighbor configured.  Will that stop it from responding to ping ?

Security stuff

My two weakest points are definitely QoS and Security.  I spent some time today reading some aspects of security that I am insecure about, but which do crop up in the NMC labs:

  • dot1x authentication
  • aaa authentication in general
  • lock-and-key access lists
  • reflexive access lists


Lab 17 involves IRDP.  I just wrote a seperate posting for this section.

Next lab date

Getting worryingly close.  But I’m not telling!



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