vpnv4 prefix dynamic update on export-map changes

[dfauluchi]

Hi guys,

I have a 76k running 12.2(33)SRE9a with this vrf configuration:

ip vrf B

rd 2:2

export map RM-R3

route-target import 2:2

route-map RM-R3 permit 10

match ip address prefix-list PL-R3

set extcommunity rt 4:4  2:2  additive

!

route-map RM-R3 permit 15

set extcommunity rt 2:2

!

ip prefix-list PL-R3 seq 5 permit 172.3.3.3/32

ip prefix-list PL-R3 seq 10 permit 172.33.33.33/32

So I expect that prefixes matching prefix-list PR-R3 will have route-target 2:2 4:4, and all other prefixes will have route-target 2:2.

The question is: What happens if I remove this line of the prefix list?

no ip prefix-list PL-R3 seq 10 permit 172.33.33.33/32

Will there be any dynamic update? Do I have to clear bgp or ip routing table?

Thanks!

Diego.

[sumit19851]

Hi Diego,

I checked in IOU with SRE9a image and observed that there is no dynamic update and we need to do "clear ip bgp <as> soft out from CE side.

Topology

R1--ebgp--[vrf CUST-A] R3----vpnv4 ibgp -----R4

ip vrf CUST-A
 rd 300:1
 export map RM-R3
 route-target export 300:1
 route-target import 300:1
!

R3#show route-map RM-R3
route-map RM-R3, permit, sequence 10
  Match clauses:
    ip address prefix-lists: PL-R3 
  Set clauses:
    extended community RT:300:1 RT:300:2 additive
  Policy routing matches: 0 packets, 0 bytes
route-map RM-R3, permit, sequence 15
  Match clauses:
  Set clauses:
    extended community RT:300:2
  Policy routing matches: 0 packets, 0 bytes

R3#show ip prefix  PL-R3
ip prefix-list PL-R3: 1 entries
   seq 5 permit 172.16.17.0/24

   seq 10 permit 172.16.19.0/24
R3#

R4#show ip b vpnv4 all 172.16.19.0/24
BGP routing table entry for 300:1:172.16.19.0/24, version 34
Paths: (1 available, best #1, table CUST-A)
  Not advertised to any peer
  100
    3.3.3.3 (metric 11) from 3.3.3.3 (3.3.3.3)
      Origin IGP, metric 0, localpref 100, valid, internal, best
      Extended Community: RT:300:1 RT:300:2
      mpls labels in/out nolabel/36
R4#

R3(config)#no ip prefix-list PL-R3 seq 10 permit 172.16.19.0/24
R3(config)#end

after 10 min

R4#show ip b vpnv4 all 172.16.19.0/24
BGP routing table entry for 300:1:172.16.19.0/24, version 34
Paths: (1 available, best #1, table CUST-A)
  Not advertised to any peer
  100
    3.3.3.3 (metric 11) from 3.3.3.3 (3.3.3.3)
      Origin IGP, metric 0, localpref 100, valid, internal, best
      Extended Community: RT:300:1 RT:300:2
      mpls labels in/out nolabel/36
R4#

R1#clear ip bgp 300 soft out
R1#

R4#show ip b vpnv4 all 172.16.19.0/24
BGP routing table entry for 300:1:172.16.19.0/24, version 50
Paths: (1 available, best #1, table CUST-A)
  Not advertised to any peer
  100
    3.3.3.3 (metric 11) from 3.3.3.3 (3.3.3.3)
      Origin IGP, metric 0, localpref 100, valid, internal, best
      Extended Community: RT:300:2
      mpls labels in/out nolabel/36

R4#

I hope it helps