04-04-2018 11:35 PM - edited 03-05-2019 10:13 AM
Hi there!
I am experiencing a problem which I suspect involves an issue with route advertisement.
The setup is as follows:
Device A 10.0.154.2/25
gateway 10.0.154.1
Router A interface 1 10.0.154.1/25 interface 2 10.0.154.250/29
interface 1 is connected to network with Device A, interface 2 is connected to network with router B
EIGRP
Router B interface 1 10.0.154.249/29 interface 2 10.0.155.234/29
interface 1 is connected to network with router A, interface 2 is connected to network with router C
BGP neighbor 10.0.155.233 (router C)
EIGRP (redistribute into BGP)
Router C interface 10.0.155.233/29
has routes to devices on 192.168.1.64/27 and 192.168.3.64/27
exact configuration unknown, but assumed to be correct
The ultimate requirement is that Device A is able to reach devices on 192.168.1.64/27 and vice versa. Only the routes required to reach this device are required to be advertised into the BGP table on 10.0.155.233.
Both device A and router A successfully connect to 10.0.155.234 (router B), but can't connect to 10.0.155.233 (router C) or further. Traceroute hops to 10.0.155.1, then 10.0.155.249 and stops here.
Router B reaches 10.0.155.233 (router C), and traceroute follows the router there as received over BGP.
Relevant config on router B:
router eigrp 100 network 10.0.0.0 network 192.168.0.0 redistribute bgp 3000 router bgp 3000 neighbor 10.0.155.233 remote-as 5000 address-family ipv4 network 10.0.152.0 network 10.0.153.0 network 10.0.154.0 redistribute connected redistribute static redistribute eigrp 100 neighbor 10.0.155.233 activate neighbor 10.0.155.233 route-map net1 out route-map net1 permit 10 match ip address 1 access-list 1 permit 10.0.154.0 0.0.0.255 #show ip bgp neighbor 10.0.155.233 advertised-routes BGP table version is 97, local router ID is 172.16.186.250 Status codes: s suppressed, d damped, h history, * valid, > best, i - internal, r RIB-failure, S Stale, m multipath, b backup-path, f RT-Filter, x best-external, a additional-path, c RIB-compressed, Origin codes: i - IGP, e - EGP, ? - incomplete RPKI validation codes: V valid, I invalid, N Not found Network Next Hop Metric LocPrf Weight Path *> 10.0.154.0/25 10.0.154.250 26882560 32768 ? *> 10.0.154.248/29 0.0.0.0 0 32768 ? Total number of prefixes 2 #show ip bgp neighbor 10.0.155.233 routes BGP table version is 97, local router ID is 172.16.186.250 Status codes: s suppressed, d damped, h history, * valid, > best, i - internal, r RIB-failure, S Stale, m multipath, b backup-path, f RT-Filter, x best-external, a additional-path, c RIB-compressed, Origin codes: i - IGP, e - EGP, ? - incomplete RPKI validation codes: V valid, I invalid, N Not found Network Next Hop Metric LocPrf Weight Path *> 192.168.1.64/27 10.0.155.233 0 5000 i *> 192.168.3.64/27 10.0.155.233 0 5000 i Total number of prefixes 2
Config on router A:
router eigrp 100 network 10.0.0.0 network 192.168.186.0 network 192.168.17.0 no auto-summary router eigrp 200 redistribute static redistribute eigrp 100 -- unrelated internal networks -- no auto-summary ip route 0.0.0.0 0.0.0.0 192.168.4.137 ip route 172.16.154.80 255.255.255.248 10.0.154.249 -- more unrelated routes -- #show ip route Codes: C - connected, S - static, R - RIP, M - mobile, B - BGP D - EIGRP, EX - EIGRP external, O - OSPF, IA - OSPF inter area N1 - OSPF NSSA external type 1, N2 - OSPF NSSA external type 2 E1 - OSPF external type 1, E2 - OSPF external type 2 i - IS-IS, su - IS-IS summary, L1 - IS-IS level-1, L2 - IS-IS level-2 ia - IS-IS inter area, * - candidate default, U - per-user static route o - ODR, P - periodic downloaded static route Gateway of last resort is 192.168.4.137 to network 0.0.0.0 10.0.0.0/16 is variably subnetted, 5 subnets, 2 masks C 10.0.154.0/25 is directly connected, FastEthernet0/1.21 D 10.0.155.240/29 [90/297244672] via 10.0.154.249, 18:33:46, Tunnel0 D 10.0.155.248/29 [90/297244672] via 10.0.154.249, 18:33:46, Tunnel0 C 10.0.154.248/29 is directly connected, Tunnel0 D 10.0.155.232/29 [90/297244672] via 10.0.154.249, 18:33:46, Tunnel0 -- lots of unrelated routes removed -- 172.16.0.0/29 is subnetted, 1 subnets S 172.16.154.80 [1/0] via 10.0.154.249 S* 0.0.0.0/0 [1/0] via 192.168.4.137
Can some genius shed some light on what's going wrong?
Thanks in advance!
Solved! Go to Solution.
04-05-2018 01:21 AM
You're missing default-metric in EIGRP config. EIGRP does not redistribute BGP routes on R2. You need to set it in either of 3 ways:
redistribute command with route-map
redistribute command with default-metric
"standalone" default-metric EIGRP command
04-04-2018 11:53 PM
There is another issue here as well:
Router A is not receiving the routes to 192.168.1.64/27 and 192.168.3.64/27 from router B over EIGRP, even though redistribute bgp is enabled on router B.
This would not explain why 10.0.155.233 is inaccessible though.
04-05-2018 01:21 AM
You're missing default-metric in EIGRP config. EIGRP does not redistribute BGP routes on R2. You need to set it in either of 3 ways:
redistribute command with route-map
redistribute command with default-metric
"standalone" default-metric EIGRP command
04-05-2018 02:32 AM
Thank you, Michal! The problem is now partially resolved.
I can confirm that adding a default-metric solved the route redistribution problem.
I'm receiving all the BGP entries over EIGRP now, but I'm still unable to reach 10.0.155.233.
I suspect that this issue, which is the big problem, is related to the BGP configuration itself. The route to it is advertised over EIGRP because I can see it in the routing table (and I can reach the router on 10.0.155.234).
I think that the router at 10.0.155.233 doesn't have a route back to the rest of the network, yet it shows in the advertised-routes table. Unfortunately, I have no access to that router, so I cannot look at the tables there. I can only troubleshoot it from the other end.
04-05-2018 06:19 AM
04-05-2018 10:18 AM
10.0.155.233 is a router sitting in front of 192.168.1.64/27, so my reasoning was that if I can't reach that, I won't go further.
"show ip route" gives thousands of pages worth of output. There are about 650k entries in the BGP table :-).
Somehow this has starting working though. I think the problem was on the other end at all, so the only problem here appears to be the metric issue you brought up earlier.
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