093 - Large Scale BGP Route Reflectors with Clusters

Tasks

Configure EBGP for R6 R4 and R5 and R3

• Configure R1 and R3 as RR for cluster 1 and router 5 as route reflector for cluster 2

• Configure SW3, SW1 and R6 as RR clint for both R1 and R3

• Configure the 

  • Configure R1 and R3 for same cluster ID

EBGP

R4

router bgp 100

neighbor 204.12.1.254 remote-as 54

R6

router bgp 100

 neighbor 54.1.1.254 remote-as 54

Router 2

router bgp 200

 bgp log-neighbor-changes

 aggregate-address 155.1.0.0 255.255.0.0

 redistribute connected

 neighbor 150.1.3.3 remote-as 100

 neighbor 150.1.3.3 ebgp-multihop 2

 neighbor 150.1.3.3 update-source Loopback0

 neighbor 150.1.5.5 remote-as 100

 neighbor 150.1.5.5 ebgp-multihop 2

 neighbor 150.1.5.5 update-source Loopback0

 neighbor 192.10.1.254 remote-as 254

 neighbor 192.10.1.254 password CISCO

 neighbor 192.10.1.254 update-source Ethernet0/0

Router 5 and 3

Router bgp 100

 neighbor 150.1.2.2 remote-as 200

 neighbor 150.1.2.2 ebgp-multihop 2

 neighbor 150.1.2.2 update-source Loopback0

R1

router bgp 100

 bgp log-neighbor-changes

 neighbor CLUSTERCLIENT peer-group

 neighbor CLUSTERCLIENT remote-as 100

 neighbor CLUSTERCLIENT update-source Loopback0

 neighbor CLUSTERCLIENT route-reflector-client

 neighbor 150.1.3.3 remote-as 100

 neighbor 150.1.3.3 update-source Loopback0

 neighbor 150.1.5.5 remote-as 100

 neighbor 150.1.5.5 update-source Loopback0

 neighbor 150.1.6.6 peer-group CLUSTERCLIENT

 neighbor 150.1.7.7 peer-group CLUSTERCLIENT

 neighbor 150.1.9.9 peer-group CLUSTERCLIENT

R3

router bgp 100

 bgp log-neighbor-changes

 neighbor CLUSTERCLIENT peer-group

 neighbor CLUSTERCLIENT remote-as 100

 neighbor CLUSTERCLIENT update-source Loopback0

 neighbor CLUSTERCLIENT route-reflector-client

 neighbor 150.1.1.1 remote-as 100

 neighbor 150.1.1.1 update-source Loopback0

 neighbor 150.1.5.5 remote-as 100

 neighbor 150.1.5.5 update-source Loopback0

 neighbor 150.1.6.6 peer-group CLUSTERCLIENT

 neighbor 150.1.7.7 peer-group CLUSTERCLIENT

 neighbor 150.1.9.9 peer-group CLUSTERCLIENT

Clients R6,SW1,SW3

Ct

router bgp 100

 neighbor 150.1.1.1 remote-as 100

 neighbor 150.1.1.1 update-source Loopback0

 neighbor 150.1.3.3 remote-as 100

 neighbor 150.1.3.3 update-source Loopback0

R5

router bgp 100

 bgp log-neighbor-changes

 neighbor CLUSTERCLIENT peer-group

 neighbor CLUSTERCLIENT remote-as 100

 neighbor CLUSTERCLIENT update-source Loopback0

 neighbor CLUSTERCLIENT route-reflector-client

 neighbor 150.1.1.1 remote-as 100

 neighbor 150.1.1.1 update-source Loopback0

 neighbor 150.1.3.3 remote-as 100

 neighbor 150.1.3.3 update-source Loopback0

 neighbor 150.1.4.4 peer-group CLUSTERCLIENT

 neighbor 150.1.8.8 peer-group CLUSTERCLIENT

 neighbor 150.1.10.10 peer-group CLUSTERCLIENT

R4 SW4 SW2

ct

router bgp 100

neighbor 150.1.5.5 remote-as 100

 neighbor 150.1.5.5 update-source Loopback0

ISSUE

Rack1R1#sib 28.119.16.0

BGP routing table entry for 28.119.16.0/24, version 131

Paths: (3 available, best #1, table default)

  Advertised to update-groups:

     2

  Refresh Epoch 1

  54

    204.12.1.254 (metric 307200) from 150.1.5.5 (150.1.5.5)

      Origin IGP, metric 0, localpref 100, valid, internal, best

      Originator: 150.1.4.4, Cluster list: 150.1.5.5

  Refresh Epoch 1

  54

    54.1.1.254 (metric 2195456) from 150.1.3.3 (150.1.3.3)

      Origin IGP, metric 0, localpref 100, valid, internal

      Originator: 150.1.6.6, Cluster list: 150.1.3.3

  Refresh Epoch 2

  54, (Received from a RR-client)

    54.1.1.254 (metric 2195456) from 150.1.6.6 (150.1.6.6)

      Origin IGP, metric 0, localpref 100, valid, internal

Router 1 is detecting three paths for a singl route

SOLUTION

Cluster ID for R3 and R1

R1 and R3

Router bgp 100

bgp cluster-id 1.2.3.4

No it has only two routes

Rack1R1#sib 28.119.16.0

BGP routing table entry for 28.119.16.0/24, version 257

Paths: (2 available, best #1, table default)

  Advertised to update-groups:

     4

  Refresh Epoch 1

  54

    204.12.1.254 (metric 307200) from 150.1.5.5 (150.1.5.5)

      Origin IGP, metric 0, localpref 100, valid, internal, best

      Originator: 150.1.4.4, Cluster list: 150.1.5.5

  Refresh Epoch 2

  54, (Received from a RR-client)

    54.1.1.254 (metric 2195456) from 150.1.6.6 (150.1.6.6)

      Origin IGP, metric 0, localpref 100, valid, internal

ISSUE 2

R1 and R3 are choosing different best paths for the same path

R3

Rack1R3#sib 28.119.16.0

BGP routing table entry for 28.119.16.0/24, version 182

Paths: (1 available, best #1, table default)

  Advertised to update-groups:

     12         13

  Refresh Epoch 2

  54, (Received from a RR-client)

    54.1.1.254 (metric 2195712) from 150.1.6.6 (150.1.6.6)

      Origin IGP, metric 0, localpref 100, valid, internal, best

R1

Rack1R1#sib 28.119.16.0

BGP routing table entry for 28.119.16.0/24, version 257

Paths: (2 available, best #1, table default)

  Advertised to update-groups:

     4

  Refresh Epoch 1

  54

    204.12.1.254 (metric 307200) from 150.1.5.5 (150.1.5.5)

      Origin IGP, metric 0, localpref 100, valid, internal, best

      Originator: 150.1.4.4, Cluster list: 150.1.5.5

  Refresh Epoch 2

  54, (Received from a RR-client)

    54.1.1.254 (metric 2195456) from 150.1.6.6 (150.1.6.6)

      Origin IGP, metric 0, localpref 100, valid, internal

Solution

Configure Lacal preferance on R4 highr then R6