BGP problem

[sudeesh79]

Hi All,

I have one Branch site connected to head Office with MPLS.
The branch site has to access internet through the head office.
The connection is :

Internet <--- [DSL_Rtr] <--- [HO_Rtr] <--- [MPLS_Cloud] <--- [Br_Rtr]

Now I cannot access internet from my branch.I cannot ping to the DSL_Rtr from branch.

DSL_RTr Config:

Default route to internet
static Routes:
30.0.0.0 255.255.255.0 172.16.1.2
30.0.1.0 255.255.255.0 172.16.1.2

herewith attached the HeadOffice and Branch Office RTR configs.

Anyone knows the problem ? Pls help..

[Kishore Chennupati]

Hi Sudeesh,

Had a look at your config

Now on the head office router , under the bgp process you are missing redistribute static. Although you are sending a default route to the MPLS cloud

but the bgp on the head office router doesnt know the next hop for the 0.0.0.0/0

====Head Office router

router bgp 64696

no synchronization

bgp log-neighbor-changes

network 30.0.0.0 mask 255.255.255.0

neighbor 10.1.0.1 remote-as 64517

neighbor 10.1.0.1 default-originate

no auto-summary

RIght now, If you do a  "sh ip bgp" on your head office router you will not see a default route. but once your put a "redistribute static" under the bgp process you will see it something like the below config

CE31A#sh ip bgp

BGP table version is 6, local router ID is 10.1.31.49

Status codes: s suppressed, d damped, h history, * valid, > best, i - internal,

              r RIB-failure, S Stale

Origin codes: i - IGP, e - EGP, ? - incomplete

   Network          Next Hop            Metric LocPrf Weight Path

*> 0.0.0.0          172.16.1.1                0         32768 ?

HTH,

Regards,

Please rate if helpful

[sudeesh79]

Hi Kishore,

Thanks for your reply.I added the command "redistribute static " in HO Router,

But still I can't ping. Please see the sh ip bgp output after I added the command. I added the network 172.16.1.0 too.

Ho#
router bgp 64696
no synchronization
bgp log-neighbor-changes
network 30.0.0.0 mask 255.255.255.0
network 172.16.1.0 mask 255.255.255.252
redistribute static
neighbor 10.1.0.1 remote-as 64517
neighbor 10.1.0.1 default-originate
no auto-summary

Ho #sh ip bgp
BGP table version is 14, local router ID is 172.16.1.2
Status codes: s suppressed, d damped, h history, * valid, > best, i - internal,
              r RIB-failure, S Stale
Origin codes: i - IGP, e - EGP, ? - incomplete

   Network          Next Hop            Metric LocPrf Weight Path
   0.0.0.0          0.0.0.0                                0 i
r> 10.1.0.0/30      10.1.0.1                               0 64517 ?
*> 10.2.0.0/30      10.1.0.1                               0 64517 ?
*> 10.3.0.0/30      10.1.0.1                               0 64517 i
*> 10.4.0.0/30      10.1.0.1                               0 64517 i
*> 10.5.0.0/30      10.1.0.1                               0 64517 i
*> 10.6.0.0/30      10.1.0.1                               0 64517 i
*> 10.7.0.0/30      10.1.0.1                               0 64517 i
*> 10.8.0.0/30      10.1.0.1                               0 64517 i
*> 30.0.0.0/24      0.0.0.0                  0         32768 i
*> 30.0.1.0/24      10.1.0.1                               0 64517 64517 i
*> 172.16.1.0/30    0.0.0.0                  0         32768 i

------------------------------------------------------------------------------------------------

BR#sh ip bgp
BGP table version is 15, local router ID is 30.0.1.250
Status codes: s suppressed, d damped, h history, * valid, > best, i - internal,
              r RIB-failure, S Stale
Origin codes: i - IGP, e - EGP, ? - incomplete

   Network          Next Hop            Metric LocPrf Weight Path
r> 0.0.0.0          10.2.0.1                               0 64517 64517 i
*> 10.1.0.0/30      10.2.0.1                               0 64517 ?
r> 10.2.0.0/30      10.2.0.1                               0 64517 ?
*> 10.3.0.0/30      10.2.0.1                               0 64517 i
*> 10.4.0.0/30      10.2.0.1                               0 64517 i
*> 10.5.0.0/30      10.2.0.1                               0 64517 i
*> 10.6.0.0/30      10.2.0.1                               0 64517 i
*> 10.7.0.0/30      10.2.0.1                               0 64517 i
*> 10.8.0.0/30      10.2.0.1                               0 64517 i
*> 30.0.0.0/24      10.2.0.1                               0 64517 64517 i
*> 30.0.1.0/24      0.0.0.0                  0         32768 i
*> 172.16.1.0/30    10.2.0.1                               0 64517 64517 i

[Kishore Chennupati · Accepted solution]

Hi Sudeesh,

let me correct myself. you didnt have to put in the redistribute static as you are using the neighbor default-originate which will advertise a default route to its neighbor unconditionally. Sorry , I overlooked it.

so are you saying you cant ping even 172.16.1.2 which is your HO router from the BR?

If you are trying to reach 172.16.1.1(DSL Router)  then it needs to have a return path back to the source. So if you are pinging from your BR which uses 10.2.0.2 as source then on the DSL router , there needs to be a route back to this source so in this case you need to put in a static route pointing to the 172.16.1.2

Put this on the DSL router ip route 10.2.0.0 255.255.255.0 172.16.1.2

Let me know how you go,

HTH,

Regards,

Please rate if helpful

[sudeesh79]

Hi Kishore,

You are right.Now it is working.

Thanks

regards

Sudeesh S