BROCADE IP PRIMER

Chapter 13: Border Gateway Protocol (BGP)specified that each router is “2” hops away from each other (the firewall is onehop; the destination is the second hop). Notice that this must be configured onboth ends. Also, notice that this function is only available with eBGP. There isnot a function for this in iBGP.BGP show CommandsWhen configuring a routing protocol, it always helps to be able to see how theprotocol is doing (and also to make sure you configured it correctly). Here aresome handy show commands that will help you do just that:• show ip route — You know by now that this command is not unique to onespecific routing protocol, but it's awfully handy (and often forgotten) whentroubleshooting routing protocols, including BGP; as a reminder, this commanddisplays the contents of your router's routing table; this shows allroutes learned, regardless of the protocol; warning: If you are receivingfull Internet routes from an ISP via BGP, you may want to specify a specificnetwork or IP address when using this command (e.g., show ip route10.0.0.0); we all have better things to do than page through over 200,000routes• show ip bgp route — Displays only routes learned through BGP; this commandincludes the AS Path, next hop, and other details of each route; thiscommand will also display all routes learned; for example, if you were multihoming,you would likely receive at least two different routes (one fromeach provider) for any given network; the show ip route command will onlyshow you the route that has been chosen as “best”; the show ip bgp routecommand will show you all the routes it has learned for each network, andwill show you which route it has chosen as “best”; warning: the same ruleapplies with show ip bgp route, although here, it's worse; you'll have over200,000 routes per ISP; once again, use show ip bgp route • show ip bgp neighbor — Displays information on all of your BGP neighbors(peers); this will tell you the neighbor's state; whether its eBGP or iBGP,BGP messages sent, all kinds of good information• show ip bgp summary — This one gets used all the time; it's a quick anddirty display of all of your neighbors (peers), what state they're in, howmany routes they've sent and received, how long the session's been up,and more; all in a nifty little table• show ip bgp config — Just like the OSPF command, this is one of the handiestever, especially if you've got a switch with a very large config; this willshow you just the section of the config pertaining to BGP284 Brocade IP Primer