R5#sh run | sec bgp
router bgp 101
bgp asnotation dot
bgp log-neighbor-changes
network 55.5.5.5 mask 255.255.255.255
neighbor 2.2.2.2 remote-as 101
neighbor 2.2.2.2 update-source Loopback0
neighbor 6.6.6.6 remote-as 1.301
neighbor 6.6.6.6 disable-connected-check
router bgp 101
bgp asnotation dot
bgp log-neighbor-changes
network 11.11.1.1 mask 255.255.255.255
neighbor 2.2.2.2 remote-as 101
neighbor 2.2.2.2 shutdown
neighbor 2.2.2.2 update-source Loopback0
neighbor 3.3.3.3 remote-as 101
neighbor 3.3.3.3 update-source Loopback0
neighbor 5.5.5.5 remote-as 101
neighbor 5.5.5.5 update-source Loopback0
R2#sh run | sec bgp
router bgp 101
bgp log-neighbor-changes
net 22.22.2.2 mask 255.255.255.255
neighbor 1.1.1.1 remote-as 101
neighbor 1.1.1.1 shutdown
neighbor 1.1.1.1 update-source Loopback0
neighbor 3.3.3.3 remote-as 101
neighbor 3.3.3.3 update-source Loopback0
neighbor 5.5.5.5 remote-as 101
neighbor 5.5.5.5 update-source Loopback0
R2#
R3#sh run | sec bgp
router bgp 101
bgp log-neighbor-changes
network 33.3.3.3 mask 255.255.255.255
neighbor 1.1.1.1 remote-as 101
neighbor 1.1.1.1 update-source Loopback0
neighbor 2.2.2.2 remote-as 101
neighbor 2.2.2.2 update-source Loopback0
neighbor 4.4.4.4 remote-as 201
neighbor 4.4.4.4 ebgp-multihop 255
neighbor 4.4.4.4 update-source Loopback0
Problem area-----
R1 Neighbor
3.3.3.3 4 101 13 14 89 0 0 00:05:13 25.5.5.5 4 101 21 18 89 0 0 00:10:55 2
Network Next Hop Metric LocPrf Weight Path
*> 11.11.1.1/32 0.0.0.0 0 32768 i
*>i 33.3.3.3/32 3.3.3.3 0 100 0 i Route from R3 (iBGP)
* i 44.4.4.4/32 4.4.4.4 0 100 0 201 i
*>i 55.5.5.5/32 5.5.5.5 0 100 0 i From R5 (iBGP)
* i 66.6.6.6/32 6.6.6.6 0 100 0 1.301 i
R1#
Same in R2
Network Next Hop Metric LocPrf Weight Path
*> 22.22.2.2/32 0.0.0.0 0 32768 i
*>i 33.3.3.3/32 3.3.3.3 0 100 0 i
* i 44.4.4.4/32 4.4.4.4 0 100 0 201 i
*>i 55.5.5.5/32 5.5.5.5 0 100 0 i
* i 66.6.6.6/32 6.6.6.6 0 100 0 65837 i
R2#
in R3
Network Next Hop Metric LocPrf Weight Path
*>i 11.11.1.1/32 1.1.1.1 0 100 0 i
*>i 22.22.2.2/32 2.2.2.2 0 100 0 i
*> 33.3.3.3/32 0.0.0.0 0 32768 i
*> 44.4.4.4/32 4.4.4.4 0 0 201 i
R3#
in rule, iBGP never forward prefix coming from iBGP peer to any iBGP peer, but this will be forward to EBGP peer.
see in R6.
R6 and R5 EBGP.
R6#sh ip bgp
Network Next Hop Metric LocPrf Weight Path
*> 11.11.1.1/32 5.5.5.5 0 101 i
*> 22.22.2.2/32 5.5.5.5 0 101 i
*> 55.5.5.5/32 5.5.5.5 0 0 101 i
*> 66.6.6.6/32 0.0.0.0 0 32768 i
R6#
*> 22.22.2.2/32 (R2 Prefix) is coming from R5 where R5-R2 has iBGP peering.
but no prefix from R3 & R4.
----Router reflector ---
To make prefix visible in all router Route reflector is the sloution.
In Route reflector,A route reflector can have three types of peers:
EBGP peers,
client peers,
nonclient peers
route reflector has the following three rules:
1. Routes learned from EBGP peers can be sent to other EBGP peers, clients, and nonclients.
2. Routes learned from client peers can be sent to EBGP peers, other client peers, and
non-clients.
3. Routes learned from non-client peers can be sent to EBGP peers, and client peers,
but not other non-clients..
Solution..
making R5 as Route reflector.
R1 & R2 are RR client
router bgp 101
neighbor 1.1.1.1 route-reflector-client
neighbor 2.2.2.2 route-reflector-client
Now in R1
R1#sh ip bgp
Network Next Hop Metric LocPrf Weight Path
*> 11.11.1.1/32 0.0.0.0 0 32768 i
*>i 22.22.2.2/32 2.2.2.2 0 100 0 i
*>i 33.3.3.3/32 3.3.3.3 0 100 0 i
* i 44.4.4.4/32 4.4.4.4 0 100 0 201 i
*>i 55.5.5.5/32 5.5.5.5 0 100 0 i
* i 66.6.6.6/32 6.6.6.6 0 100 0 1.301 i
in R5
Network Next Hop Metric LocPrf Weight Path
*>i 11.11.1.1/32 1.1.1.1 0 100 0 i
*>i 22.22.2.2/32 2.2.2.2 0 100 0 i
*> 55.5.5.5/32 0.0.0.0 0 32768 i
*> 66.6.6.6/32 6.6.6.6 0 0 1.301 i
R5#
R5#sh ip bgp 22.22.2.2
BGP routing table entry for 22.22.2.2/32, version 245
Paths: (2 available, best #2, table default)
Advertised to update-groups:
37 48 49
Refresh Epoch 1
Local, (Received from a RR-client)
2.2.2.2 (metric 156160) from 3.3.3.3 (33.3.3.3)
Origin IGP, metric 0, localpref 100, valid, internal
Originator: 2.2.2.2, Cluster list: 33.3.3.3
rx pathid: 0, tx pathid: 0
Refresh Epoch 2
Local, (Received from a RR-client)
2.2.2.2 (metric 156160) from 2.2.2.2 (2.2.2.2)
Origin IGP, metric 0, localpref 100, valid, internal, best
rx pathid: 0, tx pathid: 0x0
R5#sh ip bgp sum
neighbor 3.3.3.3 remote-as 101
neighbor 3.3.3.3 update-source Loopback0
neighbor 3.3.3.3 route-reflector-client
Now in R5
Network Next Hop Metric LocPrf Weight Path
*>i 11.11.1.1/32 1.1.1.1 0 100 0 i
* i 22.22.2.2/32 2.2.2.2 0 100 0 i
*>i 2.2.2.2 0 100 0 i
*>i 33.3.3.3/32 3.3.3.3 0 100 0 i
* i 44.4.4.4/32 4.4.4.4 0 100 0 201 i
*> 55.5.5.5/32 0.0.0.0 0 32768 i
*> 66.6.6.6/32 6.6.6.6 0 0 1.301 i
R5#
in R3
Network Next Hop Metric LocPrf Weight Path
* i 11.11.1.1/32 1.1.1.1 0 100 0 i
*>i 1.1.1.1 0 100 0 i
* i 22.22.2.2/32 2.2.2.2 0 100 0 i
*>i 2.2.2.2 0 100 0 i
*> 33.3.3.3/32 0.0.0.0 0 32768 i
*> 44.4.4.4/32 4.4.4.4 0 0 201 i
*>i 55.5.5.5/32 5.5.5.5 0 100 0 i
* i 66.6.6.6/32 6.6.6.6 0 100 0 65837 i
R3#
Network Next Hop Metric LocPrf Weight Path
* i 11.11.1.1/32 1.1.1.1 0 100 0 i
*>i 1.1.1.1 0 100 0 i
*> 22.22.2.2/32 0.0.0.0 0 32768 i
* i 33.3.3.3/32 3.3.3.3 0 100 0 i
*>i 3.3.3.3 0 100 0 i
* i 44.4.4.4/32 4.4.4.4 0 100 0 201 i
* i 55.5.5.5/32 5.5.5.5 0 100 0 i
*>i 5.5.5.5 0 100 0 i
* i 66.6.6.6/32 6.6.6.6 0 100 0 65837 i
R2#
R6#
Network Next Hop Metric LocPrf Weight Path
*> 11.11.1.1/32 5.5.5.5 0 101 i
*> 22.22.2.2/32 5.5.5.5 0 101 i
*> 33.3.3.3/32 5.5.5.5 0 101 i
*> 55.5.5.5/32 5.5.5.5 0 0 101 i
*> 66.6.6.6/32 0.0.0.0 0 32768 i
R6#
in R6 we still don't have route from R4
R4#
Network Next Hop Metric LocPrf Weight Path
*> 11.11.1.1/32 3.3.3.3 0 101 i
*> 22.22.2.2/32 3.3.3.3 0 101 i
*> 33.3.3.3/32 3.3.3.3 0 0 101 i
*> 44.4.4.4/32 0.0.0.0 0 32768 i
*> 55.5.5.5/32 3.3.3.3 0 101 i
R4#
in R4 we still don't have route from R6
Note ---Route reflector does not change path attribute like Next Hop
to solve above problem see BGP -Next hop Self
No comments:
Post a Comment