Even after waiting for the peer to fail, the routes were still in there with a next hop of 110.99.50.5 (yeah that's the peer address). Even after restarting the BGP process... and being so confused I rebooted the router... still there..
Now, in the light of day, I'm realizing that R7 was iBGP'ed to R8 and was probably learning those routes from R7, but R8 shouldn't, then readvertise them to R7 right? Split-horizon? I guess if something was going on with split-horizon... that in conjunction with my 'received/advertised' confusion (Thanks Ralph) could explain it... not sure... any more thoughts? Jason Morris _____ From: Scott Morris [mailto:[EMAIL PROTECTED] Sent: Monday, April 21, 2008 1:18 PM To: Morris, Jason L.; [email protected] Subject: RE: [OSL | CCIE_RS] Lab 22 BGP config I don't have the lab in front of me, so forgive the off-the-wall questions. Is 110.99.50.5 the ethernet address to the peer you're talking with? And you're saying the routes don't disapear right away! Remember, it's a TCP session. And there are keepalives. And like most things you have a miss a few keepalives in a row to detect the down state. And the database walker works every 60 seconds. So things aren't always immediate. Look at things like "fallover" and "graceful-restart" and other NSF-related commands if you want quicker reaction. Otherwise, you're correct all routes to an eBGP (NON-Confederation) peer should have their own IP as next hop unless there's a route-map manipulating that information. Confederation peers, even though technically eBGP, play by iBGP-'ish rules. HTH, Scott Morris, CCIE4 (R&S/ISP-Dial/Security/Service Provider) #4713, JNCIE-M #153, JNCIS-ER, CISSP, et al. CCSI/JNCI-M/JNCI-ER VP - Technical Training - IPexpert, Inc. IPexpert Sr. Technical Instructor [EMAIL PROTECTED] Telephone: +1.810.326.1444 Fax: +1.810.454.0130 http://www.ipexpert.com _____ From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Morris, Jason L. Sent: Monday, April 21, 2008 10:50 AM To: [email protected] Subject: [OSL | CCIE_RS] Lab 22 BGP config Ok maybe I'm missing something, having a brain fart or just plain don't know what I'm looking at but I'm getting some 'unexpected' output from R7 in Lab 22 when I do a 'sho ip bgp'. I've pasted the output below. If I do a 'sho ip bgp nei neighbor adv' (I believe) I should see all routes advertised to me from that neighbor, right? And if that neighbor is an eBGP peer all the 'next hop' information should be the neighbor's address, right? I found this because if I go in and shut R5's Ethernet interface I still have routes with a next hop of 110.99.50.5 (sorry I guess you'd have to be familiar with the lab to answer the question) I have the config at the time of this output saved for all routers so if you need to see something I can paste it in. Any help or clarification would be greatly appreciated. R7(config)# do sho ip bgp BGP table version is 26, local router ID is 110.90.7.7 Status codes: s suppressed, d damped, h history, * valid, > best, i - internal, r RIB-failure, S Stale Origin codes: i - IGP, e - EGP, ? - incomplete Network Next Hop Metric LocPrf Weight Path * 110.90.1.1/32 110.99.50.5 0 112 111 i *> 110.99.50.5 0 112 111 i * 110.90.2.2/32 110.99.50.6 0 112 i *> 110.99.50.5 0 112 i * 110.90.4.4/32 110.99.50.6 0 112 i *> 110.99.50.5 0 112 i * 110.90.5.5/32 110.99.50.5 0 112 i *> 110.99.50.5 0 0 112 i * 110.90.6.6/32 110.99.50.6 0 0 112 i *> 110.99.50.6 0 112 i *> 110.90.7.7/32 0.0.0.0 0 32768 i r>i110.90.8.8/32 110.90.8.8 0 100 0 i * 110.99.1.0/27 110.99.50.6 0 112 i *> 110.99.50.5 0 112 i * 110.99.1.32/27 110.99.50.5 0 112 i *> 110.99.50.5 0 0 112 i * 110.99.1.64/27 110.99.50.6 0 0 112 i Network Next Hop Metric LocPrf Weight Path *> 110.99.50.6 0 112 i r>i110.99.4.0/24 110.90.8.8 0 100 0 i * 110.99.12.0/24 110.99.50.5 0 112 111 i *> 110.99.50.5 0 112 111 i * 110.99.25.0/26 110.99.50.5 0 112 i *> 110.99.50.5 0 0 112 i * 110.99.40.0/24 110.99.50.6 0 112 i *> 110.99.50.5 0 112 i *> 110.99.50.0/24 0.0.0.0 0 32768 i * 110.99.50.6 0 0 112 i * 110.99.50.5 0 0 112 i * 110.99.69.0/30 110.99.50.6 0 0 112 i *> 110.99.50.6 0 112 i *> 110.99.78.0/24 0.0.0.0 0 32768 i * i 110.90.8.8 0 100 0 i * 150.50.200.0/24 110.99.50.5 0 112 111 i *> 110.99.50.5 0 112 111 i * 172.16.4.0/24 110.99.50.5 0 112 111 i *> 110.99.50.5 0 112 111 i R7(config)#do sho ip bgp nei 110.99.50.6 adv BGP table version is 26, local router ID is 110.90.7.7 Status codes: s suppressed, d damped, h history, * valid, > best, i - internal, r RIB-failure, S Stale Origin codes: i - IGP, e - EGP, ? - incomplete Network Next Hop Metric LocPrf Weight Path *> 110.90.1.1/32 110.99.50.5 0 112 111 i *> 110.90.2.2/32 110.99.50.5 0 112 i *> 110.90.4.4/32 110.99.50.5 0 112 i *> 110.90.5.5/32 110.99.50.5 0 0 112 i *> 110.90.6.6/32 110.99.50.6 0 112 i *> 110.90.7.7/32 0.0.0.0 0 32768 i r>i110.90.8.8/32 110.90.8.8 0 100 0 i *> 110.99.1.0/27 110.99.50.5 0 112 i *> 110.99.1.32/27 110.99.50.5 0 0 112 i *> 110.99.1.64/27 110.99.50.6 0 112 i r>i110.99.4.0/24 110.90.8.8 0 100 0 i *> 110.99.12.0/24 110.99.50.5 0 112 111 i *> 110.99.25.0/26 110.99.50.5 0 0 112 i *> 110.99.40.0/24 110.99.50.5 0 112 i *> 110.99.50.0/24 0.0.0.0 0 32768 i *> 110.99.69.0/30 110.99.50.6 0 112 i *> 110.99.78.0/24 0.0.0.0 0 32768 i Network Next Hop Metric LocPrf Weight Path *> 150.50.200.0/24 110.99.50.5 0 112 111 i *> 172.16.4.0/24 110.99.50.5 0 112 111 i Total number of prefixes 19 R7(config)#do sho ip bgp nei 110.99.50.5 adv BGP table version is 26, local router ID is 110.90.7.7 Status codes: s suppressed, d damped, h history, * valid, > best, i - internal, r RIB-failure, S Stale Origin codes: i - IGP, e - EGP, ? - incomplete Network Next Hop Metric LocPrf Weight Path *> 110.90.1.1/32 110.99.50.5 0 112 111 i *> 110.90.2.2/32 110.99.50.5 0 112 i *> 110.90.4.4/32 110.99.50.5 0 112 i *> 110.90.5.5/32 110.99.50.5 0 0 112 i *> 110.90.6.6/32 110.99.50.6 0 112 i *> 110.90.7.7/32 0.0.0.0 0 32768 i r>i110.90.8.8/32 110.90.8.8 0 100 0 i *> 110.99.1.0/27 110.99.50.5 0 112 i *> 110.99.1.32/27 110.99.50.5 0 0 112 i *> 110.99.1.64/27 110.99.50.6 0 112 i r>i110.99.4.0/24 110.90.8.8 0 100 0 i *> 110.99.12.0/24 110.99.50.5 0 112 111 i *> 110.99.25.0/26 110.99.50.5 0 0 112 i *> 110.99.40.0/24 110.99.50.5 0 112 i *> 110.99.50.0/24 0.0.0.0 0 32768 i *> 110.99.69.0/30 110.99.50.6 0 112 i *> 110.99.78.0/24 0.0.0.0 0 32768 i Network Next Hop Metric LocPrf Weight Path *> 150.50.200.0/24 110.99.50.5 0 112 111 i *> 172.16.4.0/24 110.99.50.5 0 112 111 i Total number of prefixes 19 Jason Morris
