BGP Dynamic Neighbors are a way to bring up BGP neighbors without specifically defining the neighbors remote IP address. Using the BGP Listen Range command you specify a range of IP addresses … [Read more...] about BGP Listen Range Command
Routing Protocols Tutorial - OSPF, BGP, EIGRP, RIP
All the articles on my site relating to routing protocols
The BGP weight attribute is the first on the list in the BGP best path algorithm Prefer the path with the highest WEIGHT. Note: WEIGHT is a Cisco-specific parameter. It is local to the router … [Read more...] about BGP Weight Attribute – Configuration Tutorial
As your network grows bigger and your internet traffic grows, it starts to make sense to peer directly with other networks rather than simply pay an ISP to deliver all that traffic. Peering is one of … [Read more...] about Peering with Route Servers
There are three types of OSPF authentication. Type 1 - no authentication Type 2 - clear text Type 3 - cryptographic (MD5 or SHA) Lets explore each type in a lot more detail and then look at the … [Read more...] about OSPF Authentication Types – Part 1
You may have heard that you should not run OSPF over DMVPN but do you actually know why? There is actually no technical reason why you cannot run OSPF over DMVPN but it does not scale very well. So … [Read more...] about Should you run OSPF over DMVPN?
When working with MPLs Layer 3 VPN a lot of people get stuck with the verification, simply because they don't know the bgp vpnv4 troubleshooting commands. This post will step through some of the … [Read more...] about BGP VPNv4 Troubleshooting Commands
When configuring BGP with a remote peer you might get the error message BGP peer in wrong AS [crayon-5bf4501f8b800746677318/] [crayon-5bf4501f8b829741222220/] This means that you have mis-matched … [Read more...] about BGP Peer in wrong AS
So, what is local preference in BGP? The BGP Local Preference attribute or local-pref is used to influence the outbound routing decision of a router running BGP. The local preference has to be … [Read more...] about BGP Local Preference
To achieve a full mesh of iBGP peerings between more than a few devices becomes quite an administrative challenge. To overcome this you have two tools at your disposal. BGP Confederation and Route … [Read more...] about BGP Confederation vs Route Reflector
A BGP router with synchronization enabled does not install iBGP learned routes into its routing table if it is not able to validate those routes in its IGP. The BGP syncronization rule states that … [Read more...] about What is BGP Syncronization?