CCIP

BGP – Remove Private AS

The video below shows how to remove a private AS from BGP as-path list.
Consider the topology below.
AS65300 peers eBGP with R1.  R1 then peers eBGP with R2.
R1 is then configured to remove all private ASs in the as-path when it advertises BGP routes to R2.
Watch the video below or download and watch it on your [...]

eBGP multihop

eBGP multihop can be used to loadshare traffic across multiple links between eBGP peers.
Consider the topology below.

By default eBGP sessions can only be established between directly connected interfaces.  If you want to connect to a non-connected interface or to a non-connected neighbor, you have to use the eBGP-multihop feature.
For this to work, you need to [...]

BGP – Prefix aggregation using a static route

My previous post on BGP prefix aggregation used the bgp “aggregate-address” command.  Another way to generate an aggregate is by using a static route.
Consider the toplology below.
Watch the video below to see how to configure a BGP aggregate using a static route.  Alternatively down the video here and watch it on your iPod.
The commands used [...]

Prefix Lists

IP Prefix lists can be used with BGP to permit or deny specific prefixes from being advertised or learnt to or from a neighbor.
Consider the topology below.

We will carry out three exercises.

configure a prefix list to match 192.168.1.0/24
configure a prefix list to match 192.168.1.0/24, 192.168.1.0/25, 192.168.1.0/26.
configure a prefix list to match 192.168.1.0/25 and 192.168.1.0/26

Exercise 1
We [...]

New Cisco Certifications Logo

I came across this link recently.  It suggests that Cisco Certification Logos are changing.
Follow the link to see the new logos.

BGP Route Aggregation

There are times when it is required to aggregate a set of prefixes.  There are a number of reasons why you would want to do this such as, your peering transit edge may not accept certain size prefixes, you may want to reduce the size of the routing table in some part of your network [...]