Archive for August, 2007

Minimize Fragmentation!

Wednesday, August 15th, 2007

I came across this article on Cisco’s site:

http://www.cisco.com/warp/public/105/pmtud_ipfrag.html

It’s a great read, and covers a lot of information that will help you minimize fragmentation issues across your network.  It’s great for understanding when routers fragment packets and how to configure Path-MTU-Discovery.  It’s also helpful if you have GRE or IPsec tunnels in your network.

One thing that stands out is to remember that Path-MTU-Discovery relies heavily on certain ICMP messages.  Routers reply with “fragmentation needed and DF set” and you won’t hear about it if your firewall is blocking ICMP.

 

Best CCNP Lab? Part I

Tuesday, August 7th, 2007

After recently teaching the latest CCNP exam changes, I figured everyone could benefit in knowing any new hardware requirements. The CCNP program has changed quite a bit from the previous tests. I have taken both the old and new tests and can attest to the fact that the new CCNP changes are great. For the first part of this series, I will focus on the BCMSN (aka switching) changes. For the most part, the core competencies for this haven’t changed much at all.


Take a look at the exam objectives here

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