From: Joseph Brunner (joe@affirmedsystems.com)
Date: Sat Jul 05 2008 - 20:41:07 ART
no its dynamips... ;)
I was wondering if this was a code issue or some secret squirrel feature I'm
not aware of... redistributing ALL BGP table stuff into eigrp with the
"redistribute bgp" under router eigrp 10. We wouldn't want to miss anything
right?
Lower admin than eigrp, huh? let me try... with AD 54 static routes to null0
as you suggested...
very nice, Luan! seems to have went away, but does explain my original
issue... ;( why do routes slip from the BGP table, not the routing table
into EIGRP...
NYCORPHQ1#show ip bgp
BGP table version is 8, local router ID is 10.74.74.11
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 66.66.1.1 0 0 11401 i
*> 66.55.5.0/25 0.0.0.0 0 32768 i
*> 66.55.5.128/25 0.0.0.0 0 32768 i
NYCORPHQ2#show ip bgp
BGP table version is 4, local router ID is 10.74.74.12
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 66.66.2.1 0 0 11401 i
*> 66.55.5.0/25 0.0.0.0 0 32768 i
*> 66.55.5.128/25 0.0.0.0 0 32768 i
-Joe
-----Original Message-----
From: nobody@groupstudy.com [mailto:nobody@groupstudy.com] On Behalf Of Luan
Nguyen
Sent: Saturday, July 05, 2008 7:18 PM
To: Joseph Brunner
Cc: Cisco certification
Subject: Re: Interesting BGP/EIGRP interaction
I assume you can't do debug stuffs since it's production routers?
I could put this in my lab later tonight and look...it seems very
interesting.
But in the mean time, while not route to null0 at a lower admin than EIGRP
and see what happen? who cares if it's 254 or 54 right?
-Luan
On Sat, Jul 5, 2008 at 6:20 PM, Joseph Brunner <joe@affirmedsystems.com>
wrote:
> Good afternoon,
>
>
>
> Perhaps someone can shed some light on this strange, vexing issue.
>
>
>
> Normally we are lead to believe that the "redistribute" command
> redistributes routes that are in the routing table using the protocol
> referenced by the redistribute command. However I have a situation where
> I'm
> running EBGP between two edge routers and the isp routers. These router DO
> NOT run IBGP between them. They DO run EIGRP between them. Eigrp is
> configured to redistribute bgp learned routes, so that the default route
> learned from the isp and redistributed to EIGRP learned internally.
>
>
>
> However the following is happening;
>
>
>
> 1. Eigrp is automatically redistributing the bgp holddown routes
> static
> to null0 (used to keep the routes in the bgp table permanently). Each Edge
> router is configured with identical static routes to null for the
netblocks
> advertised into bgp.
> 2. The edge router with the the superior metric configured for the
> bgp-> eigrp redistribute command is becoming the router advertising these
> static routes into eigrp as external routes. So while eigrp is only
> configured with "redistribute bgp" they are indeed redistributing static
> routes (the hold down routes to null0), as IF THE "REDISTRIBUTE STATIC"
> command had been configured under router eigrp.
> 3. This is causing the "show ip bgp" output on the egde router
picking
> up the eigrp static routes to list the other router's eigrp neighbor
> address
> as the "next hop" while is should be 0.0.0.0 (originated on this router).
> The EDGE router with the inferior metric in the "redistribute bgp" command
> under router eigrp see's this.
> 4. How is this possible?????!?!?! Why is "redistribute bgp 65000"
> under
> router eigrp matching the bgp table, not the routes know via bgp!
>
>
>
> Please check the below.
>
>
>
> NYCORPHQ1#show ip bgp
>
> BGP table version is 4, local router ID is 10.74.74.11
>
> 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 66.66.1.1 0 0 11401 i
>
> *> 66.55.5.0/25 0.0.0.0 0 32768 i
>
> *> 66.55.5.128/25 0.0.0.0 0 32768 i
>
>
>
> NYCORPHQ1#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 66.66.1.1 to network 0.0.0.0
>
>
>
> 66.0.0.0/8 is variably subnetted, 3 subnets, 2 masks
>
> C 66.66.1.0/30 is directly connected, Serial0/0
>
> S 66.55.5.0/25 is directly connected, Null0
>
> S 66.55.5.128/25 is directly connected, Null0
>
> C 192.168.5.0/24 is directly connected, FastEthernet0/1
>
> 10.0.0.0/8 is variably subnetted, 7 subnets, 3 masks
>
> C 10.74.74.11/32 is directly connected, Loopback1
>
> D 10.74.74.12/32 [90/156160] via 10.10.10.2, 00:07:03,
> FastEthernet1/0
>
> C 10.10.10.0/24 is directly connected, FastEthernet1/0
>
> C 10.1.1.0/30 is directly connected, FastEthernet0/0
>
> D 10.74.74.1/32 [90/409600] via 10.1.1.2, 00:07:03, FastEthernet0/0
>
> D 10.1.1.4/30 [90/284160] via 10.10.10.2, 00:07:04, FastEthernet1/0
>
> D 10.254.0.0/24 [90/284160] via 10.1.1.2, 00:07:04, FastEthernet0/0
>
> B* 0.0.0.0/0 [20/0] via 66.66.1.1, 00:08:51
>
>
>
>
>
> NYCORPHQ2#show ip bgp
>
> BGP table version is 4, local router ID is 10.74.74.12
>
> 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 66.66.2.1 0 0 11401 i
>
> *> 66.55.5.0/25 10.10.10.1 307200 32768 i
>
> *> 66.55.5.128/25 10.10.10.1 307200 32768 i
>
>
>
> NYCORPHQ2#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 66.66.2.1 to network 0.0.0.0
>
>
>
> 66.0.0.0/8 is variably subnetted, 3 subnets, 2 masks
>
> C 66.66.2.0/30 is directly connected, Serial1/0
>
> D EX 66.55.5.0/25 [170/307200] via 10.10.10.1, 00:06:35, Ethernet0/1
>
> D EX 66.55.5.128/25 [170/307200] via 10.10.10.1, 00:06:35, Ethernet0/1
>
> 10.0.0.0/8 is variably subnetted, 7 subnets, 3 masks
>
> D 10.74.74.11/32 [90/409600] via 10.10.10.1, 00:06:35, Ethernet0/1
>
> C 10.74.74.12/32 is directly connected, Loopback1
>
> C 10.10.10.0/24 is directly connected, Ethernet0/1
>
> D 10.1.1.0/30 [90/307200] via 10.10.10.1, 00:06:35, Ethernet0/1
>
> [90/307200] via 10.1.1.6, 00:06:35, Ethernet0/0
>
> D 10.74.74.1/32 [90/409600] via 10.1.1.6, 00:06:35, Ethernet0/0
>
> C 10.1.1.4/30 is directly connected, Ethernet0/0
>
> D 10.254.0.0/24 [90/284160] via 10.1.1.6, 00:06:35, Ethernet0/0
>
> B* 0.0.0.0/0 [20/0] via 66.66.2.1, 00:07:41
>
>
>
>
>
> NYCORPHQ1#show run
>
> interface FastEthernet0/0
>
> ip address 10.1.1.1 255.255.255.252
>
> duplex auto
>
> speed auto
>
> !
>
> interface Serial0/0
>
> ip address 66.66.1.2 255.255.255.252
>
> ip virtual-reassembly
>
> clock rate 2000000
>
> !
>
> interface FastEthernet1/0
>
> ip address 10.10.10.1 255.255.255.0
>
> ip virtual-reassembly
>
> speed 10
>
> full-duplex
>
> !
>
> router eigrp 10
>
> redistribute bgp 65000 metric 10000 100 255 1 1500
>
> network 10.0.0.0
>
> no auto-summary
>
> !
>
> router bgp 65000
>
> no synchronization
>
> bgp log-neighbor-changes
>
> network 66.55.5.0 mask 255.255.255.128
>
> network 66.55.5.128 mask 255.255.255.128
>
> neighbor 66.66.1.1 remote-as 11401
>
> neighbor 66.66.1.1 route-map nycorphq1 out
>
> no auto-summary
>
> !
>
> ip forward-protocol nd
>
> ip route 66.55.5.0 255.255.255.128 Null0 254
>
> ip route 66.55.5.128 255.255.255.128 Null0 254
>
> !
>
> !
>
> no ip http server
>
> no ip http secure-server
>
> !
>
> !
>
> ip prefix-list 66.55.5.0-25 seq 5 permit 66.55.5.0/25
>
> !
>
> ip prefix-list 66.55.5.128-25 seq 5 permit 66.55.5.128/25
>
> !
>
> route-map nycorphq1 permit 10
>
> match ip address prefix-list 66.55.5.0-25
>
> set metric 50
>
> !
>
> route-map nycorphq1 permit 20
>
> match ip address prefix-list 66.55.5.128-25
>
> set metric 500
>
> !
>
> !
>
> !
>
> !
>
> control-plane
>
> !
>
>
>
> NYCORPHQ2#show run
>
>
>
> !
>
> interface Ethernet0/0
>
> ip address 10.1.1.5 255.255.255.252
>
> half-duplex
>
> !
>
> interface Ethernet0/1
>
> ip address 10.10.10.2 255.255.255.0
>
> ip virtual-reassembly
>
> full-duplex
>
> !
>
> interface Ethernet0/2
>
> no ip address
>
> shutdown
>
> half-duplex
>
> !
>
> interface Ethernet0/3
>
> no ip address
>
> shutdown
>
> half-duplex
>
> !
>
> interface Serial1/0
>
> ip address 66.66.2.2 255.255.255.252
>
> ip virtual-reassembly
>
> serial restart-delay 0
>
> clock rate 2016000
>
> !
>
> interface Serial1/1
>
> no ip address
>
> shutdown
>
> serial restart-delay 0
>
> !
>
> interface Serial1/2
>
> no ip address
>
> shutdown
>
> serial restart-delay 0
>
> !
>
> interface Serial1/3
>
> no ip address
>
> shutdown
>
> serial restart-delay 0
>
> !
>
> router eigrp 10
>
> redistribute bgp 65000 metric 1500 100 255 1 1500
>
> network 10.0.0.0
>
> no auto-summary
>
> !
>
> router bgp 65000
>
> no synchronization
>
> bgp log-neighbor-changes
>
> network 66.55.5.0 mask 255.255.255.128
>
> network 66.55.5.128 mask 255.255.255.128
>
> neighbor 66.66.2.1 remote-as 11401
>
> neighbor 66.66.2.1 route-map nycorphq2 out
>
> no auto-summary
>
> !
>
> no ip http server
>
> no ip http secure-server
>
> !
>
> ip forward-protocol nd
>
> ip route 66.55.5.0 255.255.255.128 Null0 254
>
> ip route 66.55.5.128 255.255.255.128 Null0 254
>
> !
>
> !
>
> !
>
> ip prefix-list 66.55.5.0-25 seq 5 permit 66.55.5.0/25
>
> !
>
> ip prefix-list 66.55.5.128-25 seq 5 permit 66.55.5.128/25
>
> !
>
> route-map nycorphq2 permit 10
>
> match ip address prefix-list 66.55.5.128-25
>
> set metric 50
>
> !
>
> route-map nycorphq2 permit 20
>
> match ip address prefix-list 66.55.5.0-25
>
> set metric 500
>
> !
>
> !
>
> !
>
> control-plane
>
> !
>
> !
>
> !
>
> !
>
>
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