Best Practice: Don’t use bandwidth statement

It’s considered a best practice to not configure the ‘bandwidth’ statement on physical router interfaces. This is because the routing protocol will throttle updates propagated through this interface. The one case where you’ll need to consider configuring the bandwidth statement is on Tunnel interfaces. This is because the default bandwidth of a Tunnel interface isContinue reading “Best Practice: Don’t use bandwidth statement”

A note on versions

Greg over at networkgremlins hand an interesting insight into the features in IOS versions. It’s primarily concerned with the SP lab, but will apply to any CCDE lab they set up as well… depending on the IOS version. Check it out here.

Installing VMWARE Server 1.0.5 on Ubuntu 8.04 – 64 bit editionapt-get install build-essentialapt-get install ia32-libsapt-get install xinetdapt-get install kernel-packagesudo touch /etc/vmware/ssl/rui.key sudo touch /etc/vmware/ssl/rui.crtdownload http://vmkernelnewbies.googlegroups.com/web/vmware-any-any-update-116.tgzunzip/untar & run runme.plsudo cp /lib/libgcc_s.so.1 /usr/lib/vmware/lib/libgcc_s.so.1/sudo cp /usr/lib/libpng12.so.0 /usr/lib/vmware/lib/libpng12.so.0/

Fast Convergence Techniques

In reading the SRND on router access layer there are a few key takeaways.On page 5 it says: “Cisco recommends a routed network core in all cases.” Let’s examine the reasoning behind this statement. First of all, what’s the alternative? You can have a layer-2 core where your devices simply switch frames at layer-2. ThinkContinue reading “Fast Convergence Techniques”

Aggregation and Suboptimal Routing

This is a continuation from the last topic: route aggregation. When you advertise an aggregate, you effectively ‘hide’ topological information and can cause suboptimal routing. If you have 10.1.0.0/16 and 10.2.0.0/16 summarized into 10.0.0.0/8 and advertised via two links, one of the links may be the ‘best’ path for the traffic to take, but sinceContinue reading “Aggregation and Suboptimal Routing”

IP Routing: Aggregation Concepts and Techniques

Purpose of route aggregation Scalability and fault isolation How to Aggregate What is the purpose of route aggregation? We aggregate routes to decrease the sizes of our routing tables, hide information, and decrease convergence times. The boundary device – ASBR / ABR / whatever – will use a route summarization technique to aggregate prefixes towardsContinue reading “IP Routing: Aggregation Concepts and Techniques”