Advertising a default route in BGP

There are four ways to distribute a default route in BGP. Three of them, the network, the default-information originate and redistribution from another routing protocol, are all similar in the resulting effect: they will inject the default route into BGP RIB and it will be advertised to all BGP neighbors. The difference is inContinue reading “Advertising a default route in BGP”

MP-eBGP Configuration

Some information on how to configure multiprotocol extended Border Gateway Protocol (MP-EBGP). Extended BGP allows for the transport of routing information for multiple network layer protocols IPv6, VPNv4, and others. MP-BGP allows you to have a unicast routing topology different from a multicast routing topology, which helps to control the network and resources. In this example, theContinue reading “MP-eBGP Configuration”

More BGP next-hop-self

From the below you can see the next hop for network is which is outsite of 65000 AS, and router jazz doesn’t have a route to it.  BGP will not put into routing table because it doesn’t know how to reach next hop, you can see this below: By adding the next-hop-self commandContinue reading “More BGP next-hop-self”

eBGP Configuration with a Loopback Address

You can also configure eBGP using a loopback address (or any other operational interface) as shown in this section. Loopback interfaces are used in this manner to guarantee reachability in networks with multiple paths as shown in the Load Sharing Using the Loopback Address as a BGP Neighbor section of Load Sharing with BGP in SingleContinue reading “eBGP Configuration with a Loopback Address”

Basic eBGP Configuration

In this configuration, the router owen is in AS 300 and Router jazz is in AS 400. Peers must be directly connected when using eBGP.  If they are not directly connected, the neighbor ebgp-multihop command must be used and a path through an IGP or static route to reach the peer must exist in order forContinue reading “Basic eBGP Configuration”