From: Anh P Tran (anhtran81@optusnet.com.au)
Date: Mon Sep 05 2005 - 03:51:07 GMT-3
Hi groups,
My diagram is below which is lab 14 in IE workbook
Eth0/0----R4--------S0/0-----------------S1/1----R3
|
|
ETH0/0
----------------- FA0/0------R6-----------Dialer1 PPPoA ------------------
BB1
R3, R4, R6 is IBGP within AS 100
R3 is the Route reflector for R4 and R6
R6 has EBGP peer with BB1 which in AS 54
When R4 originate the its Eth0/0 route 167.1.4.0 to BGP, R6 received this
route via R3 and advertise to BB1 as EBGP routes.
I believed the BGP RFC states that when you advertise routes to EBGP peer,
the next hop should be set to the peering address which in this case should
be the dialer 1 ip .
However, this is not the case with my lab as R6 tried to advertise the route
and keep the next-hop as from R4 to BB1.
BB1 rejected the route as it complained the route is EBGP and NEXT-HOP
should be directly connected.
Is it the IOS bugs or I have done something wrong. I had included all the
relevant configuration and debug.
Thanks guys
Anh Tran
*************** R4 config ***************
Rack1R4#show run int eth0/0
Building configuration...
Current configuration : 78 bytes
!
interface Ethernet0/0
ip address 167.1.4.4 255.255.255.0
half-duplex
end
interface Serial0/0
description *** PVC TO R3 ***
bandwidth 64
ip address 167.1.34.4 255.255.255.0
ip router isis
encapsulation frame-relay
backup interface BRI0/0
backup load 20 10
load-interval 30
isis network point-to-point
frame-relay map clns 413 broadcast
frame-relay map ip 167.1.34.3 413 broadcast
frame-relay map ip 167.1.34.4 413
no frame-relay inverse-arp
router bgp 100
no synchronization
bgp router-id 150.1.4.4
bgp log-neighbor-changes
network 167.1.4.0 mask 255.255.255.0
neighbor 150.1.3.3 remote-as 100
neighbor 150.1.3.3 update-source Loopback0
Rack1R4#show ip bgp regexp ^$
BGP table version is 60, local router ID is 150.1.4.4
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
*> 167.1.4.0/24 0.0.0.0 0 32768 i
****** R3 CONFIG ******
interface Serial1/1
description *** PVC TO R4 ***
bandwidth 64
ip address 167.1.34.3 255.255.255.0
encapsulation frame-relay
load-interval 30
serial restart_delay 0
no frame-relay inverse-arp
interface Ethernet0/0
description *** CONNECT TO R6 ***
ip address 204.12.1.3 255.255.255.0
ip router isis
half-duplex
router bgp 100
no synchronization
bgp router-id 150.1.3.3
bgp log-neighbor-changes
neighbor IBGP peer-group
neighbor IBGP remote-as 100
neighbor IBGP update-source Loopback0
neighbor IBGP route-reflector-client
neighbor IBGP send-community
neighbor 150.1.4.4 peer-group IBGP
neighbor 150.1.6.6 peer-group IBGP
Rack1R3#show ip bgp regexp ^$
BGP table version is 68, local router ID is 150.1.3.3
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
*>i167.1.4.0/24 150.1.4.4 0 100 0 i
******* R6 CONFIG ******
interface Dialer1
description *** CONNECT TO BB1 ***
ip address 54.1.8.6 255.255.255.0
ip router isis
encapsulation ppp
dialer pool 1
dialer-group 1
ppp chap refuse
ppp pap sent-username ROUTER6 password 0 CISCO
isis circuit-type level-1
interface FastEthernet0/0
description *** CONNECT TO R3 ***
ip address 204.12.1.6 255.255.255.0
ip router isis
duplex half
isis circuit-type level-2-only
router bgp 100
no synchronization
bgp router-id 150.1.6.6
bgp log-neighbor-changes
neighbor 54.1.8.254 remote-as 54
neighbor 150.1.3.3 remote-as 100
neighbor 150.1.3.3 update-source Loopback0
Rack1R6#show ip bgp summary
BGP router identifier 150.1.6.6, local AS number 100
BGP table version is 26, main routing table version 26
15 network entries using 1515 bytes of memory
17 path entries using 816 bytes of memory
6 BGP path attribute entries using 360 bytes of memory
2 BGP rrinfo entries using 48 bytes of memory
3 BGP AS-PATH entries using 72 bytes of memory
1 BGP community entries using 24 bytes of memory
0 BGP route-map cache entries using 0 bytes of memory
0 BGP filter-list cache entries using 0 bytes of memory
BGP using 2835 total bytes of memory
BGP activity 16/1 prefixes, 18/1 paths, scan interval 60 secs
Neighbor V AS MsgRcvd MsgSent TblVer InQ OutQ Up/Down
State/PfxRcd
54.1.8.254 4 54 34 45 26 0 0 00:27:12 8
150.1.3.3 4 100 48 45 26 0 0 00:27:13 7
Rack1R6#show ip bgp regexp ^$
BGP table version is 26, local router ID is 150.1.6.6
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
*>i167.1.4.0/24 150.1.4.4 0 100 0 i
Debug on the BB1 router
BB1#show ip bgp summary | ex Active
BGP router identifier 212.18.3.1, local AS number 54
BGP table version is 25, main routing table version 25
8 network entries using 808 bytes of memory
8 path entries using 384 bytes of memory
2 BGP path attribute entries using 120 bytes of memory
1 BGP community entries using 24 bytes of memory
2 BGP route-map cache entries using 40 bytes of memory
0 BGP filter-list cache entries using 0 bytes of memory
BGP using 1376 total bytes of memory
BGP activity 22/10 prefixes, 25/13 paths, scan interval 60 secs
Neighbor V AS MsgRcvd MsgSent TblVer InQ OutQ Up/Down
State/PfxRcd
54.1.8.6 4 100 145 112 25 0 0 00:29:34 0
BB1#debug ip bgp updates in
BGP updates debugging is on (inbound)
BB1#
Sep 4 23:28:25.021: BGP(0): 54.1.8.6 send UPDATE (format) 112.0.0.0/8, next
54.1.8.254, metric 0, path
Sep 4 23:28:25.021: BGP(0): 54.1.8.6 send UPDATE (prepend, chgflags: 0x0)
113.0.0.0/8, next 54.1.8.254, metric 0, path
Sep 4 23:28:25.021: BGP(0): 54.1.8.6 send UPDATE (format) 114.0.0.0/8, next
54.1.8.254, metric 0, path
Sep 4 23:28:25.021: BGP(0): 54.1.8.6 send UPDATE (prepend, chgflags: 0x0)
115.0.0.0/8, next 54.1.8.254, metric 0, path
Sep 4 23:28:25.021: BGP(0): 54.1.8.6 send UPDATE (format) 116.0.0.0/8, next
54.1.8.254, metric 0, path
Sep 4 23:28:25.025: BGP(0): 54.1.8.6 send UPDATE (prepend, chgflags: 0x0)
117.0.0.0/8, next 54.1.8.254, metric 0, path
Sep 4 23:28:25.025: BGP(0): 54.1.8.6 send UPDATE (prepend, chgflags: 0x0)
118.0.0.0/8, next 54.1.8.254, metric 0, path
Sep 4 23:28:25.025: BGP(0): 54.1.8.6 send UPDATE (prepend, chgflags: 0x0)
119.0.0.0/8, next 54.1.8.254, metric 0, path
Sep 4 23:28:25.025: BGP: 54.1.8.6 Advertised Nexthop 204.12.1.254: N
on-local or Nexthop and peer Not on same interface
Sep 4 23:28:25.025: BGP(0): 54.1.8.6 rcv UPDATE w/ attr: nexthop
204.12.1.254, origin i, originator 0.0.0.0, path 100 54, community ,
extended community
Sep 4 23:28:25.029: BGP(0): 54.1.8.6 rcv UPDATE about 28.119.16.0/24 --
DENIED due to: AS-PATH contains our own AS; non-connected NEXTHOP;
Sep 4 23:28:25.029: BGP(0): 54.1.8.6 rcv UPDATE about 28.119.17.0/24 --
DENIED due to: AS-PATH contains our own AS; non-connected NEXTHOP;
Sep 4 23:28:25.029: BGP: 54.1.8.6 Advertised Nexthop 192.10.1.254:
Non-local or Nexthop and peer Not on same interface
Sep 4 23:28:25.029: BGP(0): 54.1.8.6 rcv UPDATE w/ attr: nexthop
192.10.1.254, origin ?, originator 0.0.0.0, path 100 254, community ,
extended community
Sep 4 23:28:25.029: BGP(0): 54.1.8.6 rcv UPDATE about 205.90.31.0/24 --
DENIED due to: non-connected NEXTHOP;
Sep 4 23:28:25.029: BGP(0): 54.1.8.6 rcv UPDATE about 220.20.3.0/24 --
DENIED due to: non-connected NEXTHOP;
Sep 4 23:28:25.029: BGP(0): 54.1.8.6 rcv UPDATE about 222.22.2.0/24 --
DENIED due to: non-connected NEXTHOP;
Sep 4 23:28:25.029: BGP: 54.1.8.6 Advertised Nexthop 150.1.5.5: Non-local
or Nexthop and peer Not on same interface
Sep 4 23:28:25.029: BGP(0): 54.1.8.6 rcv UPDATE w/ attr: nexthop 150.1.5.5,
origin i, metric 10, originator 0.0.0.0, path 100, community , extended
community
Sep 4 23:28:25.029: BGP(0): 54.1.8.6 rcv UPDATE about 167.1.5.0/24 --
DENIED due to: non-connected NEXTHOP;
Sep 4 23:28:25.029: BGP: 54.1.8.6 Advertised Nexthop 150.1.4.4: Non-local
or Nexthop and peer Not on same interface <<<
Sep 4 23:28:25.029: BGP(0): 54.1.8.6 rcv UPDATE w/ attr: nexthop 150.1.4.4,
origin i, metric 10, originator 0.0.0.0, path 100, community , extended
community
Sep 4 23:28:25.029: BGP(0): 54.1.8.6 rcv UPDATE about 167.1.4.0/24 --
DENIED due to: non-connected NEXTHOP; <<<<<< This is got me confuse
BB1#
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