Solved: Re: Routing issue on WAN - Page 2

Kevin Melton · ‎05-17-2010

I am currently working for a client and helping them redesign part of their network. The client has a pretty nice network scheme in that they have their Headquarters connected to their Disaster Recovery site with an MPLS circuit, and then also a Frame Relay which was the legacy circuit prior to the MPLS.

Last week I configured a new Cisco Switch for them at the Disaster Recover site. We are configuring a new WAN network with IP address 192.168.36.0. I have a management address configured on the new switch of 192.168.36.5. Currently this switch connects to the ASA which has an address of 192.168.36.1. I have eigrp configured on the WAN switch. When I check the ASA it shows that it has the network 192.168.36.0 directly connected. From there is where everything seems strange.

I need for the Headquarters site to use the MPLS circuit to route to the new switch. For whatever reason, the path is taking the Frame Relay network. Eigrp is configured on most devices. In some places, RIP is used. I think EIGRP is distrubuted into RIP at some point. What I do know is that I wish I could stop the network 192.168.36.0 from being advertised over the Frame so It would choose the MPLS circuit on the Headquarters side.

I made one change on the Headquarters side last week thinking that it would have the effect of forcing the route to traverse the MPLS circuit. But instead what happened was the traceroute from headquarters to the 192.168.36.0 network showed the packet hit the Headquarters MPLS router, but instead of taking the MPLS over, the MPLS router then shipped the packet to the Frame router and sent it over the Frame Relay network.

Jon or Guiseppe if you get this I could really use your guys help!

I am including a diagram of the network...

Thanks

Kevin

Kevin Melton · ‎05-18-2010

Jon

here is the "sho ip bgp" from HQ router

GAMPLSRTR01#sho ip bgp
BGP table version is 866, local router ID is 172.31.100.1
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
*> 0.0.0.0          192.168.15.1             0         32768 i
*> 10.254.32.0/24   12.115.94.169                          0 7018 65002 ?
*> 10.254.242.0/24 192.168.15.1            30         32768 ?
*> 10.254.243.0/24 192.168.15.1            30         32768 ?
*> 10.254.252.0/24 192.168.15.1            30         32768 ?
*> 10.254.254.0/24 192.168.15.1            30         32768 ?
*> 12.38.168.0/24   12.115.94.169                          0 7018 2386 i
*> 12.113.82.104/30 12.115.94.169            0             0 7018 ?
*> 12.115.94.164/30 12.115.94.169            0             0 7018 ?
r> 12.115.94.168/30 12.115.94.169            0             0 7018 ?
*> 135.89.152.56/29 12.115.94.169                          0 7018 2386 i
*> 135.89.152.128/28
                    12.115.94.169                          0 7018 2386 i
*> 135.89.154.152/29
                    12.115.94.169                          0 7018 2386 i
*> 135.89.157.160/28
                    12.115.94.169                          0 7018 2386 i
   Network          Next Hop            Metric LocPrf Weight Path
*> 172.16.32.0/24   12.115.94.169                          0 7018 65002 ?
*> 172.16.33.0/24   12.115.94.169                          0 7018 65002 ?
*> 172.16.44.0/24   12.115.94.169                          0 7018 65002 i
*> 172.16.45.0/24   12.115.94.169                          0 7018 65002 i
*> 172.16.47.0/24   12.115.94.169                          0 7018 65002 i
*> 172.16.132.0/29 12.115.94.169                          0 7018 65002 ?
*> 172.16.132.8/30 12.115.94.169                          0 7018 65002 i
*> 172.16.132.12/30 12.115.94.169                          0 7018 65002 ?
*> 172.16.133.0/24 12.115.94.169                          0 7018 65002 ?
*> 172.27.4.32/28   12.115.94.169                          0 7018 65002 ?
*> 172.27.5.32/28   12.115.94.169                          0 7018 65002 i
*> 172.31.100.0/24 0.0.0.0                  0         32768 i
*> 172.31.200.0/24 12.115.94.169                          0 7018 65002 i
*> 192.168.1.0      192.168.15.1            30         32768 ?
*> 192.168.2.0      192.168.15.1            30         32768 ?
*> 192.168.3.0      192.168.15.1            30         32768 ?
*> 192.168.4.0      192.168.15.1            30         32768 ?
*> 192.168.5.0      0.0.0.0                  0         32768 i
*> 192.168.7.0      192.168.15.1            30         32768 ?
*> 192.168.11.0     192.168.15.5            30         32768 ?
*> 192.168.15.0     0.0.0.0                  0         32768 i
*> 192.168.31.0     12.115.94.169                          0 7018 65002 ?
   Network          Next Hop            Metric LocPrf Weight Path
*> 192.168.32.0     12.115.94.169                          0 7018 65002 ?
*> 192.168.33.0     12.115.94.169                          0 7018 65002 ?
*> 192.168.34.0     12.115.94.169                          0 7018 65002 ?
*> 192.168.36.0     12.115.94.169                          0 7018 65002 i
*> 192.168.101.0    12.115.94.169                          0 7018 65002 ?
*> 192.168.102.0    12.115.94.169                          0 7018 65002 ?
*> 192.168.103.0    12.115.94.169                          0 7018 65002 ?
*> 192.168.104.0    12.115.94.169                          0 7018 65002 ?
*> 192.168.105.0    12.115.94.169                          0 7018 65002 i
*> 192.168.154.0    12.115.94.169                          0 7018 65002 ?
*> 192.168.176.0    192.168.15.1            30         32768 ?
*> 192.168.253.5/32 192.168.15.1            30         32768 ?
*> 192.168.254.0    192.168.15.1            30         32768 ?
GAMPLSRTR01#
Here is the bgp config from the DR site router

router bgp 65002
bgp log-neighbor-changes
neighbor 12.115.94.165 remote-as 7018
neighbor 12.115.94.165 timers 60 180
!
address-family ipv4
redistribute eigrp 13 metric 100 route-map eigrp-bgp-rm
neighbor 12.115.94.165 activate
no auto-summary
no synchronization
network 172.16.132.8 mask 255.255.255.252
network 172.31.200.0 mask 255.255.255.0
network 192.168.36.0
network 192.168.38.1 mask 255.255.255.255
network 192.168.105.0
exit-address-family

Perhaps you didnt see it but i had posted a couple of posts ago that I have at least "band-aided" the issue by adding the 192.168.36.0 network to the "address-family ipv4 subheading under the bgp configuration. Prior to adding the network there it was not being advertised across the MPLS from DR to HQ. Once the 36 network was added there it showed up, and now routes properly. I am still having trouble with the Loopback network though (192.168.38.1/32) configured on the new switch at DR site.

Thanks!

Jon Marshall · ‎05-18-2010

Kevin

Thanks for this. Yes i missed that from your previous post and was actually thinking along those lines ie. it had not been advertised from the DR site under the BGP config.

The config is a bit confusing and i need to lab something up to test. I looked at the DR config and noticed there is no network statement under EIGRP for 192.168.36.0 hence when you redsitribute EIGRP into BGP it won't add that one. But then for some reason there is also a network statement under the address-family for 172.16.132.0/30 even though there is a network statement under EIGRP for that. Bit confusing.

However your solution is valid, it's just that with EIGRP redistribution you shouldn't need that network statement under the address-family. However if you didn't want EIGRP to start on that interface so it wasn't advertised out, possibly via the frame-relay network then your solution is a better one.

As for the loopback, how does the loopback appear in the routing table ie. if you do a "sh ip route" on the DR MPLS router does it show

192.168.38.1 255.255.255.255

or

192.168.38.0 255.255.255.0

Whatever it shows in the routing table must match your network statement so if it says 192.168.38.0 255.255.255.0 in the routing table the network statement needs to be -

network 192.168.38.0 mask 255.255.255.0

Jon

Kevin Melton · ‎05-19-2010

Jon

Regarding the loopback address, you were correct about the network statement. I had formerly used 192.168.38.1/32, but the DR router had it in its routing table as 192.168.38.0/24. So I changed the statement in the bgp config under "address family ipv4" to be 192.168.38.0 vs. 192.168.38.1/32. Once this change was made, then the MPLS router at HQ was receiving the update.

Funny thing is, at least on the network I am using at HQ, if I do a traceroute from a workstation at 192.168.7.0 (this network is the user network off of our Core Sw at HQ), the traceroute still takes me over the frame. I will have to look at this a little closer.

Thanks and hope you are well

Kevin

Jon Marshall · ‎05-19-2010

Kevin

Funny thing is, at least on the network I am using at HQ, if I do a traceroute from a workstation at 192.168.7.0 (this network is the user network off of our Core Sw at HQ), the traceroute still takes me over the frame. I will have to look at this a little closer.

It will if you are advertising the same DR network both over the MPLS network and over the frame-relay network. Only on the MPLS HQ router will the BGP route take preference. Once the route has been redistributed into EIGRP it will have an AD of 170. This is fine but if the same route is advertised over the frame-relay network it will have AD of 90 because there is no redistribution going on.

This is what i meant when i said if you advertise the same DR route via MPLS and frame-relay it will always take the frame-relay route.

Jon