eBGP issue !! routes advertised but not received

[csc010854800]

Hi ,

i am facing a strange issue. can somebody explain or resolve.

CE 1 is VRRP primary and CE 2 is VRRP Secondary router.

when i shut fa 1/0/0 on CE 2  , everything is fine , routes are learned on CE 1 and PE 1 and again routes are advertised to PE 2 and again to CE 2.

Problem comes when we unshut the port Fa 1/0/0 on CE 2 , routes are advertised on CE 2 but are not received on PE 2.

when i remove the static routes and again put the static routes , PE 2 starts receiving the routes.

not able to get the answer , why it is happening.

diagram and all the config are attached.

[Marwan ALshawi]

From ur diagram I can see that you are increasing the local preference of received route on PE1 which will let the route to be more preferred over PE 1 than ce 2 ?

[Kishore Chennupati]

Marwan,

Although PE2 receives better routes from PE1  still it should show the prefixes learned from CE2 in the BGP table.  Perhaps you are talking about the RIB.

On your CE2 you  receive the 10.36.35.0/24 10.36.46.0/24  from CE1 and you are  advertising those networks to PE2 via network command. can you do a "sh  ip bgp neighbor 172.30.0.226 adver" when the problem happens?

Technically you should be able to advertise them . But  you need to know if the CE2 is actually advertising them or PE2 is  dropping them.

HTH

Kishore

[csc010854800]

Kishor,

yes , CE 2 is advertising the routes to PE 2 , but PE 2 is not able to receive the routes.. as two CE 1 and CE 2 are in VRRP mode , CE 2 is secondary switch , is it anything to do with it. 

[milan.kulik]

Hi,

are you able to check if CE2 is really advertising those static prefixes to PE2?

Isn't it for some strange reason still advertising the prefixes it had received fro PE2 when the Fa1/0/0 had been down?

(That would explain PE2 dropping the prefixes received.)

sh ip bgp  10.36.32.0/24 on CE2

should be enough.

HTH,

Milan

[csc010854800]

dis bgp routing-table 10.36.33.0

BGP local router ID : 192.168.240.48
Local AS number : 65011
Paths:   2 available, 1 best, 1 select
BGP routing table entry information of 10.36.33.0/24:
Network route.
From: 0.0.0.0 (0.0.0.0)
Route Duration: 00h00m45s
Direct Out-interface: Ethernet0/0/1
Original nexthop: 10.36.32.1
Qos information : 0x0
AS-path Nil, origin igp, MED 0, pref-val 0, valid, local, best, select, pre 60
Advertised to such 1 peers:
    172.30.0.230
BGP routing table entry information of 10.36.33.0/24:
From: 172.30.0.230 (172.30.0.222)
Route Duration: 00h00m45s
Direct Out-interface: Ethernet0/0/1
Original nexthop: 172.30.0.230
Qos information : 0x0
AS-path 55410 55410 55410, origin igp, pref-val 0, valid, external, pre 255, not preferred for route type
Not advertised to any peer yet

dis bgp routing-table peer 172.30.0.230 advertised-routes

Total Number of Routes: 3

BGP Local router ID is 192.168.240.48
Status codes: * - valid, > - best, d - damped,
               h - history,  i - internal, s - suppressed, S - Stale
               Origin : i - IGP, e - EGP, ? - incomplete

      Network            NextHop        MED        LocPrf    PrefVal Path/Ogn

*>   10.36.33.0/24      0.0.0.0         0                     0      i
*>   10.36.34.0/24      0.0.0.0         0                     0      i
*>   10.36.42.0/24      0.0.0.0         0                     0      i