From: ccie_sp@hotmail.com
Date: Thu Feb 01 2007 - 07:56:25 ART
Hi,
I'm having a hard time with my remote triggered BGP blackhole config
Router4 should change the next-hop to 192.0.2.1 instead of 4.4.4.4 (it's
loopback), But I do not see that behaviour.
I have 2 routers with the following config:
ROUTER4:
========================
router bgp 345 bgp router-id 4.4.4.4 no bgp default ipv4-unicast no bgp
default route-target filter bgp log-neighbor-changes neighbor 5.5.5.5
remote-as 345 neighbor 5.5.5.5 update-source Loopback0 ! address-family ipv4
redistribute static metric 1 route-map black <---- route-map for BGP
blackhole neighbor 5.5.5.5 activate neighbor 5.5.5.5 next-hop-self neighbor
5.5.5.5 send-community neighbor 5.5.5.5 soft-reconfiguration inbound neighbor
5.5.5.5 send-label no auto-summary no synchronization network 4.4.4.4 mask
255.255.255.255 exit-address-family !
route-map black permit 10 match tag 99 set ip next-hop 192.0.2.1 set origin
igp set community no-export!ip route 44.44.44.44 255.255.255.255 Null0 tag
99ip route 192.0.2.0 255.255.255.0 Null0
SHOW OUTPUT:
R4#show ip bgp | inc 44.44*> 44.44.44.44/32 192.0.2.1 1
32768 iR4#show ip route 44.44.44.44Routing entry for 44.44.44.44/32 Known via
"static", distance 1, metric 0 (connected) Tag 99 Redistributing via bgp 345
Advertised by bgp 345 metric 1 route-map black Routing Descriptor Blocks: *
directly connected, via Null0 Route metric is 0, traffic share count is 1
Route tag 99
Looks fine....
BUT!!
ROUTER5:
=============
ip route 192.0.2.0 255.255.255.0 Null0
router bgp 345 bgp router-id 5.5.5.5 no bgp default ipv4-unicast no bgp
default route-target filter bgp log-neighbor-changes neighbor IBGP peer-group
neighbor IBGP remote-as 345 neighbor IBGP update-source Loopback0 neighbor
4.4.4.4 remote-as 345 neighbor 4.4.4.4 peer-group IBGP neighbor 4.4.4.4
update-source Loopback0 ! address-family ipv4 neighbor IBGP activate neighbor
IBGP route-reflector-client neighbor IBGP next-hop-self neighbor IBGP
send-community neighbor IBGP route-map path out neighbor IBGP send-label
neighbor 4.4.4.4 peer-group IBGP no auto-summary no synchronization network
5.5.5.5 mask 255.255.255.255 exit-address-family
============
R5#show ip route 192.0.2.1Routing entry for 192.0.2.0/24 Known via "static",
distance 1, metric 0 (connected) Routing Descriptor Blocks: * directly
connected, via Null0 Route metric is 0, traffic share count is 1
R5#show ip rout 44.44.44.44Routing entry for 44.44.44.44/32 Known via "bgp
345", distance 200, metric 1, type internal Last update from 4.4.4.4 00:09:06
ago Routing Descriptor Blocks: * 4.4.4.4, from 4.4.4.4, 00:09:06 ago
Route metric is 1, traffic share count is 1 AS Hops 0R5#show ip bgp | inc
44.44*>i44.44.44.44/32 4.4.4.4 1 100 0 iR5#show ip
bgp neighbors 4.4.4.4 received-routesBGP table version is 17, local router ID
is 5.5.5.5Status codes: s suppressed, d damped, h history, * valid, > best, i
- internal, S StaleOrigin codes: i - IGP, e - EGP, ? -
incomplete
Network Next Hop Metric LocPrf Weight Path*>i4.4.4.4/32
4.4.4.4 0 100 0 i*>i44.44.44.44/32 4.4.4.4
1 100 0 i <<=== SO ROUTER4 (lo0: 4.4.4.4) is not changing the
next-hop to 192.0.2.1???
ROUTER4
========
R4#show ip bgp neighbors 5.5.5.5 advertised-routesBGP table version is 233,
local router ID is 4.4.4.4Status codes: s suppressed, d damped, h history, *
valid, > best, i - internal, S StaleOrigin codes: i - IGP, e -
EGP, ? - incomplete
Network Next Hop Metric LocPrf Weight Path*> 4.4.4.4/32
0.0.0.0 0 32768 i*> 44.44.44.44/32 192.0.2.1
1 32768 i <====== Huh... it's changing the next-hop to 192.0.2.1.
I do not get it..
When redistributing the static route into BGP (on R4) it should match the tag
99, and change the next-hop to "192.0.2.1", then R5 should drop the packet
locally to Null0, since it has a static route for 192.0.2.0/24 pointing to
Null0...
What's wrong with my config!
Thanks guys and girls
This archive was generated by hypermail 2.1.4 : Thu Mar 01 2007 - 07:38:45 ART