How would you configure BGP in a simple way?

Configuring BGP is really pretty simple if you understand what you are doing. However, because there are many different BGP designs, some BGP configurations can be complex. Let’s look at a common configuration: you want to multi-home your network to two Internet service providers. That way, if one provider goes down, your inbound and outbound Internet traffic won’t miss a beat. Here is the basic configuration to do this:

router bgp 123456 – this statement is the first statement you use to enter BGP router configuration mode. The 123456 represents your AS number that you obtained from ARIN.

no synchronization – this command tells BGP that to advertise routes to BGP neighbors, those routes don’t have to exist in the routing table.

neighbor X.X.X.X – the neighbor statements are used to configure your connections to your BGP neighbors. The X.X.X.X is the IP address for your neighbor. The “remote-as” statement is the remote AS number for that neighbor. You can see the optional description statement to help you identify that neighbor. In this example, we have two neighbors.

no auto-summary - tells BGP not to summarize IP addresses that you are advertising to neighbors as classful IP address boundaries.

The most common BGP commands used to look at BGP status are show ip bgp summary and show ip bgp. The show ip bgp summary command shows the status of BGP. The show ip bgp command shows the BGP routing table.