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BGP in PE-CE and MP-BGP running together, unable to reach specific IPs in CE

Arun Nair
Level 1
Level 1

Hi experts,

I am just starting out with CCIE(R & S and SP, dont know which one I'm gonna give, I love both). I am just trying to come up with a lab design that I will be constructing based on my mistakes and experiences. I'd like you all to help me out here with this scenario.

Untitled.jpg

The routers I am working on as of now are the ones connected to the FR switch(less important, just plain OSPF over broadcast network), CE4, CE1, CE2, PE1 and PE4.

I am running BGP between CE1-PE1, CE2-PE4, and OSPF between CE1-CE4. MP-BGP runs creating the super backbone between PE1 and PE4(PE2 is just a P router, never found the time to really rename it).

Relevant outputs are given below:

CE1#sh ip route

Codes: C - connected, S - static, R - RIP, M - mobile, B - BGP

       D - EIGRP, EX - EIGRP external, O - OSPF, IA - OSPF inter area

       N1 - OSPF NSSA external type 1, N2 - OSPF NSSA external type 2

       E1 - OSPF external type 1, E2 - OSPF external type 2

       i - IS-IS, su - IS-IS summary, L1 - IS-IS level-1, L2 - IS-IS level-2

       ia - IS-IS inter area, * - candidate default, U - per-user static route

       o - ODR, P - periodic downloaded static route

Gateway of last resort is not set

     1.0.0.0/32 is subnetted, 1 subnets

B       1.1.1.1 [20/0] via 10.1.1.10, 01:01:21

     50.0.0.0/32 is subnetted, 1 subnets

O       50.50.50.50 [110/75] via 10.1.1.1, 00:59:57, Ethernet0/0

     70.0.0.0/32 is subnetted, 1 subnets

O       70.70.70.70 [110/75] via 10.1.1.1, 00:59:57, Ethernet0/0

     33.0.0.0/32 is subnetted, 1 subnets

O       33.33.33.33 [110/21] via 10.1.1.1, 00:59:57, Ethernet0/0

     80.0.0.0/32 is subnetted, 1 subnets

O       80.80.80.80 [110/75] via 10.1.1.1, 00:59:57, Ethernet0/0

     20.0.0.0/32 is subnetted, 1 subnets

O       20.20.20.20 [110/75] via 10.1.1.1, 00:59:57, Ethernet0/0

     172.19.0.0/16 is variably subnetted, 5 subnets, 2 masks

B       172.19.20.0/30 [20/0] via 10.1.1.10, 00:45:06

O       172.19.10.4/32 [110/138] via 10.1.1.1, 00:59:57, Ethernet0/0

O       172.19.10.1/32 [110/74] via 10.1.1.1, 00:59:57, Ethernet0/0

O       172.19.10.3/32 [110/10] via 10.1.1.1, 00:59:57, Ethernet0/0

O       172.19.10.2/32 [110/74] via 10.1.1.1, 00:59:57, Ethernet0/0

     111.0.0.0/32 is subnetted, 1 subnets

C       111.111.111.111 is directly connected, Loopback1

     40.0.0.0/32 is subnetted, 1 subnets

O       40.40.40.40 [110/139] via 10.1.1.1, 00:59:57, Ethernet0/0

     10.0.0.0/30 is subnetted, 4 subnets

C       10.1.1.8 is directly connected, Ethernet0/1

C       10.1.1.0 is directly connected, Ethernet0/0

O       10.1.1.4 [110/20] via 10.1.1.1, 00:59:57, Ethernet0/0

B       10.1.1.32 [20/0] via 10.1.1.10, 01:01:21

     11.0.0.0/24 is subnetted, 1 subnets

C       11.11.11.0 is directly connected, Loopback0

     90.0.0.0/32 is subnetted, 1 subnets

O       90.90.90.90 [110/75] via 10.1.1.1, 00:59:57, Ethernet0/0

     60.0.0.0/32 is subnetted, 1 subnets

O       60.60.60.60 [110/75] via 10.1.1.1, 00:59:57, Ethernet0/0

     30.0.0.0/32 is subnetted, 1 subnets

O       30.30.30.30 [110/11] via 10.1.1.1, 00:59:57, Ethernet0/0

CE1#sh ip bgp su

BGP router identifier 111.111.111.111, local AS number 2

BGP table version is 25, main routing table version 25

20 network entries using 2340 bytes of memory

21 path entries using 1092 bytes of memory

14/12 BGP path/bestpath attribute entries using 1736 bytes of memory

2 BGP AS-PATH entries using 48 bytes of memory

0 BGP route-map cache entries using 0 bytes of memory

0 BGP filter-list cache entries using 0 bytes of memory

BGP using 5216 total bytes of memory

BGP activity 21/1 prefixes, 22/1 paths, scan interval 60 secs

Neighbor        V    AS MsgRcvd MsgSent   TblVer  InQ OutQ Up/Down  State/PfxRcd

10.1.1.10       4     1      71      78       25    0    0 01:02:01        4

CE1#sh ip ospf ne

Neighbor ID     Pri   State           Dead Time   Address         Interface

30.30.30.30       0   FULL/  -        00:00:30    10.1.1.1        Ethernet0/0

CE1#

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

PE1#sh ip route

Codes: C - connected, S - static, R - RIP, M - mobile, B - BGP

       D - EIGRP, EX - EIGRP external, O - OSPF, IA - OSPF inter area

       N1 - OSPF NSSA external type 1, N2 - OSPF NSSA external type 2

       E1 - OSPF external type 1, E2 - OSPF external type 2

       i - IS-IS, su - IS-IS summary, L1 - IS-IS level-1, L2 - IS-IS level-2

       ia - IS-IS inter area, * - candidate default, U - per-user static route

       o - ODR, P - periodic downloaded static route

Gateway of last resort is not set

     200.200.200.0/32 is subnetted, 2 subnets

C       200.200.200.200 is directly connected, Loopback1

O       200.200.200.201 [110/21] via 10.1.1.22, 01:03:42, Ethernet1/1

                        [110/21] via 10.1.1.18, 01:03:42, Ethernet1/0

     10.0.0.0/30 is subnetted, 5 subnets

O       10.1.1.24 [110/20] via 10.1.1.22, 01:03:42, Ethernet1/1

O       10.1.1.28 [110/20] via 10.1.1.18, 01:03:42, Ethernet1/0

C       10.1.1.16 is directly connected, Ethernet1/0

C       10.1.1.20 is directly connected, Ethernet1/1

O       10.1.1.36 [110/20] via 10.1.1.18, 01:03:42, Ethernet1/0

PE1#

PE1#

PE1#

PE1#sh ip route vrf CE1

Routing Table: CE1

Codes: C - connected, S - static, R - RIP, M - mobile, B - BGP

       D - EIGRP, EX - EIGRP external, O - OSPF, IA - OSPF inter area

       N1 - OSPF NSSA external type 1, N2 - OSPF NSSA external type 2

       E1 - OSPF external type 1, E2 - OSPF external type 2

       i - IS-IS, su - IS-IS summary, L1 - IS-IS level-1, L2 - IS-IS level-2

       ia - IS-IS inter area, * - candidate default, U - per-user static route

       o - ODR, P - periodic downloaded static route

Gateway of last resort is not set

     1.0.0.0/32 is subnetted, 1 subnets

C       1.1.1.1 is directly connected, Loopback0

     50.0.0.0/32 is subnetted, 1 subnets

B       50.50.50.50 [20/75] via 11.11.11.11, 01:01:41

     70.0.0.0/32 is subnetted, 1 subnets

B       70.70.70.70 [20/75] via 11.11.11.11, 01:01:41

     33.0.0.0/32 is subnetted, 1 subnets

B       33.33.33.33 [20/21] via 11.11.11.11, 01:02:55

     80.0.0.0/32 is subnetted, 1 subnets

B       80.80.80.80 [20/75] via 11.11.11.11, 01:01:41

     20.0.0.0/32 is subnetted, 1 subnets

B       20.20.20.20 [20/75] via 11.11.11.11, 01:01:10

     172.19.0.0/16 is variably subnetted, 5 subnets, 2 masks

B       172.19.20.0/30 [200/0] via 200.200.200.201, 00:47:01

B       172.19.10.4/32 [20/138] via 11.11.11.11, 01:01:41

B       172.19.10.1/32 [20/74] via 11.11.11.11, 01:01:41

B       172.19.10.3/32 [20/10] via 11.11.11.11, 01:02:25

B       172.19.10.2/32 [20/74] via 11.11.11.11, 01:01:10

     40.0.0.0/32 is subnetted, 1 subnets

B       40.40.40.40 [20/139] via 11.11.11.11, 01:01:41

     10.0.0.0/30 is subnetted, 4 subnets

C       10.1.1.8 is directly connected, Ethernet1/2

B       10.1.1.0 [20/0] via 11.11.11.11, 01:02:55

B       10.1.1.4 [20/20] via 11.11.11.11, 01:02:55

B       10.1.1.32 [200/0] via 200.200.200.201, 01:03:18

     11.0.0.0/8 is variably subnetted, 2 subnets, 2 masks

S       11.11.11.11/32 [1/0] via 10.1.1.9, Ethernet1/2

B       11.11.11.0/24 [20/0] via 11.11.11.11, 01:02:55

     90.0.0.0/32 is subnetted, 1 subnets

B       90.90.90.90 [20/75] via 11.11.11.11, 01:01:41

     60.0.0.0/32 is subnetted, 1 subnets

B       60.60.60.60 [20/75] via 11.11.11.11, 01:01:41

     30.0.0.0/32 is subnetted, 1 subnets

B       30.30.30.30 [20/11] via 11.11.11.11, 01:02:55

PE1#

PE1#

PE1#

PE1#sh ip bg

PE1#sh ip bgp vpa

PE1#sh ip bgp vpn

PE1#sh ip bgp vpnv4 all

BGP table version is 31, local router ID is 200.200.200.200

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

Route Distinguisher: 1:1 (default for vrf CE1)

*> 1.1.1.1/32       0.0.0.0                  0         32768 i

*> 10.1.1.0/30      11.11.11.11              0             0 2 ?

*> 10.1.1.4/30      11.11.11.11             20             0 2 ?

*> 10.1.1.8/30      0.0.0.0                  0         32768 ?

*                   11.11.11.11              0             0 2 ?

*>i10.1.1.32/30     200.200.200.201          0    100      0 ?

*> 11.11.11.0/24    11.11.11.11              0             0 2 ?

*> 20.20.20.20/32   11.11.11.11             75             0 2 ?

*> 30.30.30.30/32   11.11.11.11             11             0 2 ?

*> 33.33.33.33/32   11.11.11.11             21             0 2 ?

*> 40.40.40.40/32   11.11.11.11            139             0 2 ?

*> 50.50.50.50/32   11.11.11.11             75             0 2 ?

*> 60.60.60.60/32   11.11.11.11             75             0 2 ?

*> 70.70.70.70/32   11.11.11.11             75             0 2 ?

*> 80.80.80.80/32   11.11.11.11             75             0 2 ?

*> 90.90.90.90/32   11.11.11.11             75             0 2 ?

*> 172.19.10.1/32   11.11.11.11             74             0 2 ?

*> 172.19.10.2/32   11.11.11.11             74             0 2 ?

*> 172.19.10.3/32   11.11.11.11             10             0 2 ?

*> 172.19.10.4/32   11.11.11.11            138             0 2 ?

*>i172.19.20.0/30   200.200.200.201          0    100      0 3 i

PE1#

PE1#

PE1#

PE1#sh ip bgp vpnv4 all su

BGP router identifier 200.200.200.200, local AS number 1

BGP table version is 31, main routing table version 31

20 network entries using 2740 bytes of memory

21 path entries using 1428 bytes of memory

23/13 BGP path/bestpath attribute entries using 2852 bytes of memory

2 BGP AS-PATH entries using 48 bytes of memory

2 BGP extended community entries using 48 bytes of memory

0 BGP route-map cache entries using 0 bytes of memory

0 BGP filter-list cache entries using 0 bytes of memory

BGP using 7116 total bytes of memory

BGP activity 21/1 prefixes, 22/1 paths, scan interval 15 secs

Neighbor        V    AS MsgRcvd MsgSent   TblVer  InQ OutQ Up/Down  State/PfxRcd

11.11.11.11     4     2      79      72       31    0    0 01:03:07       17

200.200.200.201 4     1      70      83       31    0    0 01:04:17        2

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

PE4#sh ip route

Codes: C - connected, S - static, R - RIP, M - mobile, B - BGP

       D - EIGRP, EX - EIGRP external, O - OSPF, IA - OSPF inter area

       N1 - OSPF NSSA external type 1, N2 - OSPF NSSA external type 2

       E1 - OSPF external type 1, E2 - OSPF external type 2

       i - IS-IS, su - IS-IS summary, L1 - IS-IS level-1, L2 - IS-IS level-2

       ia - IS-IS inter area, * - candidate default, U - per-user static route

       o - ODR, P - periodic downloaded static route

Gateway of last resort is not set

     200.200.200.0/32 is subnetted, 2 subnets

O       200.200.200.200 [110/21] via 10.1.1.29, 01:04:40, Ethernet1/0

                        [110/21] via 10.1.1.25, 01:04:40, Ethernet1/1

C       200.200.200.201 is directly connected, Loopback1

     10.0.0.0/30 is subnetted, 5 subnets

C       10.1.1.24 is directly connected, Ethernet1/1

C       10.1.1.28 is directly connected, Ethernet1/0

O       10.1.1.16 [110/20] via 10.1.1.29, 01:04:40, Ethernet1/0

O       10.1.1.20 [110/20] via 10.1.1.25, 01:04:40, Ethernet1/1

O       10.1.1.36 [110/20] via 10.1.1.29, 01:04:40, Ethernet1/0

PE4#

PE4#

PE4#sh ip route vp

PE4#sh ip route vp

PE4#sh ip route vpn

PE4#sh ip bg      

PE4#sh ip bgp vp

PE4#sh ip bgp vpnv4 all

BGP table version is 46, local router ID is 200.200.200.201

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

Route Distinguisher: 1:1 (default for vrf CE2)

*>i1.1.1.1/32       200.200.200.200          0    100      0 i

*>i10.1.1.0/30      200.200.200.200          0    100      0 2 ?

*>i10.1.1.4/30      200.200.200.200         20    100      0 2 ?

*>i10.1.1.8/30      200.200.200.200          0    100      0 ?

*  10.1.1.32/30     12.12.12.12              0             0 3 i

*>                  0.0.0.0                  0         32768 ?

*>i11.11.11.0/24    200.200.200.200          0    100      0 2 ?

*>i20.20.20.20/32   200.200.200.200         75    100      0 2 ?

*>i30.30.30.30/32   200.200.200.200         11    100      0 2 ?

*>i33.33.33.33/32   200.200.200.200         21    100      0 2 ?

*>i40.40.40.40/32   200.200.200.200        139    100      0 2 ?

*>i50.50.50.50/32   200.200.200.200         75    100      0 2 ?

*>i60.60.60.60/32   200.200.200.200         75    100      0 2 ?

*>i70.70.70.70/32   200.200.200.200         75    100      0 2 ?

*>i80.80.80.80/32   200.200.200.200         75    100      0 2 ?

*>i90.90.90.90/32   200.200.200.200         75    100      0 2 ?

*>i172.19.10.1/32   200.200.200.200         74    100      0 2 ?

*>i172.19.10.2/32   200.200.200.200         74    100      0 2 ?

*>i172.19.10.3/32   200.200.200.200         10    100      0 2 ?

*>i172.19.10.4/32   200.200.200.200        138    100      0 2 ?

*> 172.19.20.0/30   12.12.12.12              0             0 3 i

PE4#

PE4#

PE4#

PE4#sh ip bgp vpnv4 all su

BGP router identifier 200.200.200.201, local AS number 1

BGP table version is 46, main routing table version 46

20 network entries using 2740 bytes of memory

21 path entries using 1428 bytes of memory

15/13 BGP path/bestpath attribute entries using 1860 bytes of memory

2 BGP AS-PATH entries using 48 bytes of memory

2 BGP extended community entries using 48 bytes of memory

0 BGP route-map cache entries using 0 bytes of memory

0 BGP filter-list cache entries using 0 bytes of memory

BGP using 6124 total bytes of memory

BGP activity 21/1 prefixes, 22/1 paths, scan interval 15 secs

Neighbor        V    AS MsgRcvd MsgSent   TblVer  InQ OutQ Up/Down  State/PfxRcd

12.12.12.12     4     3      53      76       46    0    0 00:48:21        2

200.200.200.200 4     1      84      71       46    0    0 01:05:15       18

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

CE2#ter len 0

CE2#sh ip route

Codes: C - connected, S - static, R - RIP, M - mobile, B - BGP

       D - EIGRP, EX - EIGRP external, O - OSPF, IA - OSPF inter area

       N1 - OSPF NSSA external type 1, N2 - OSPF NSSA external type 2

       E1 - OSPF external type 1, E2 - OSPF external type 2

       i - IS-IS, su - IS-IS summary, L1 - IS-IS level-1, L2 - IS-IS level-2

       ia - IS-IS inter area, * - candidate default, U - per-user static route

       o - ODR, P - periodic downloaded static route

Gateway of last resort is not set

     1.0.0.0/32 is subnetted, 1 subnets

B       1.1.1.1 [20/0] via 10.1.1.34, 00:48:51

     50.0.0.0/32 is subnetted, 1 subnets

B       50.50.50.50 [20/0] via 10.1.1.34, 00:48:51

     100.0.0.0/30 is subnetted, 1 subnets

C       100.100.100.0 is directly connected, Serial1/0

     70.0.0.0/32 is subnetted, 1 subnets

B       70.70.70.70 [20/0] via 10.1.1.34, 00:48:51

     33.0.0.0/32 is subnetted, 1 subnets

B       33.33.33.33 [20/0] via 10.1.1.34, 00:48:51

     80.0.0.0/32 is subnetted, 1 subnets

B       80.80.80.80 [20/0] via 10.1.1.34, 00:48:51

     20.0.0.0/32 is subnetted, 1 subnets

B       20.20.20.20 [20/0] via 10.1.1.34, 00:48:51

     172.19.0.0/16 is variably subnetted, 5 subnets, 2 masks

C       172.19.20.0/30 is directly connected, Ethernet0/1

B       172.19.10.4/32 [20/0] via 10.1.1.34, 00:48:51

B       172.19.10.1/32 [20/0] via 10.1.1.34, 00:48:51

B       172.19.10.3/32 [20/0] via 10.1.1.34, 00:48:51

B       172.19.10.2/32 [20/0] via 10.1.1.34, 00:48:51

     40.0.0.0/32 is subnetted, 1 subnets

B       40.40.40.40 [20/0] via 10.1.1.34, 00:48:51

     10.0.0.0/30 is subnetted, 4 subnets

B       10.1.1.8 [20/0] via 10.1.1.34, 00:48:51

B       10.1.1.0 [20/0] via 10.1.1.34, 00:48:51

B       10.1.1.4 [20/0] via 10.1.1.34, 00:48:51

C       10.1.1.32 is directly connected, Ethernet0/0

     11.0.0.0/24 is subnetted, 1 subnets

B       11.11.11.0 [20/0] via 10.1.1.34, 00:48:51

     12.0.0.0/32 is subnetted, 1 subnets

C       12.12.12.12 is directly connected, Loopback0

     90.0.0.0/32 is subnetted, 1 subnets

B       90.90.90.90 [20/0] via 10.1.1.34, 00:48:51

     60.0.0.0/32 is subnetted, 1 subnets

B       60.60.60.60 [20/0] via 10.1.1.34, 00:48:51

     30.0.0.0/32 is subnetted, 1 subnets

B       30.30.30.30 [20/0] via 10.1.1.34, 00:48:51

CE2#

CE2#sh ip bg

CE2#sh ip bgp su

BGP router identifier 172.19.20.1, local AS number 3

BGP table version is 21, main routing table version 21

20 network entries using 2340 bytes of memory

21 path entries using 1092 bytes of memory

6/4 BGP path/bestpath attribute entries using 744 bytes of memory

2 BGP AS-PATH entries using 48 bytes of memory

0 BGP route-map cache entries using 0 bytes of memory

0 BGP filter-list cache entries using 0 bytes of memory

BGP using 4224 total bytes of memory

BGP activity 20/0 prefixes, 21/0 paths, scan interval 60 secs

Neighbor        V    AS MsgRcvd MsgSent   TblVer  InQ OutQ Up/Down  State/PfxRcd

10.1.1.34       4     1      76      53       21    0    0 00:48:54       19

CE2#  

CE2#

CE2#sh ip ospf ne

CE2#

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

CE4#

CE4#sh ip rout

Codes: C - connected, S - static, R - RIP, M - mobile, B - BGP

       D - EIGRP, EX - EIGRP external, O - OSPF, IA - OSPF inter area

       N1 - OSPF NSSA external type 1, N2 - OSPF NSSA external type 2

       E1 - OSPF external type 1, E2 - OSPF external type 2

       i - IS-IS, su - IS-IS summary, L1 - IS-IS level-1, L2 - IS-IS level-2

       ia - IS-IS inter area, * - candidate default, U - per-user static route

       o - ODR, P - periodic downloaded static route

Gateway of last resort is not set

     1.0.0.0/32 is subnetted, 1 subnets

O E2    1.1.1.1 [110/1] via 10.1.1.2, 01:03:56, Ethernet1/0

     50.0.0.0/32 is subnetted, 1 subnets

O       50.50.50.50 [110/65] via 172.19.10.1, 01:03:56, Serial0/0

     70.0.0.0/32 is subnetted, 1 subnets

O       70.70.70.70 [110/65] via 172.19.10.1, 01:03:56, Serial0/0

     33.0.0.0/32 is subnetted, 1 subnets

O       33.33.33.33 [110/11] via 10.1.1.6, 01:03:56, Ethernet1/1

     80.0.0.0/32 is subnetted, 1 subnets

O       80.80.80.80 [110/65] via 172.19.10.1, 01:03:56, Serial0/0

     20.0.0.0/32 is subnetted, 1 subnets

O       20.20.20.20 [110/65] via 172.19.10.2, 01:03:56, Serial0/0

     172.19.0.0/16 is variably subnetted, 5 subnets, 3 masks

O E2    172.19.20.0/30 [110/1] via 10.1.1.2, 00:49:05, Ethernet1/0

O       172.19.10.4/32 [110/128] via 172.19.10.1, 01:03:56, Serial0/0

O       172.19.10.1/32 [110/64] via 172.19.10.1, 01:03:56, Serial0/0

C       172.19.10.0/24 is directly connected, Serial0/0

O       172.19.10.2/32 [110/64] via 172.19.10.2, 01:03:56, Serial0/0

     40.0.0.0/32 is subnetted, 1 subnets

O       40.40.40.40 [110/129] via 172.19.10.1, 01:03:56, Serial0/0

     10.0.0.0/30 is subnetted, 4 subnets

O       10.1.1.8 [110/20] via 10.1.1.2, 01:03:56, Ethernet1/0

C       10.1.1.0 is directly connected, Ethernet1/0

C       10.1.1.4 is directly connected, Ethernet1/1

O E2    10.1.1.32 [110/1] via 10.1.1.2, 01:03:56, Ethernet1/0

     11.0.0.0/32 is subnetted, 1 subnets

O       11.11.11.11 [110/11] via 10.1.1.2, 01:03:56, Ethernet1/0

     90.0.0.0/32 is subnetted, 1 subnets

O       90.90.90.90 [110/65] via 172.19.10.1, 01:03:56, Serial0/0

     60.0.0.0/32 is subnetted, 1 subnets

O       60.60.60.60 [110/65] via 172.19.10.1, 01:03:56, Serial0/0

     30.0.0.0/32 is subnetted, 1 subnets

C       30.30.30.30 is directly connected, Loopback0

CE4#

CE4#

CE4#

CE4#sh ip ospf ne

Neighbor ID     Pri   State           Dead Time   Address         Interface

20.20.20.20       0   FULL/  -        00:01:45    172.19.10.2     Serial0/0

90.90.90.90       0   FULL/  -        00:01:33    172.19.10.1     Serial0/0

33.33.33.33       0   FULL/  -        00:00:33    10.1.1.6        Ethernet1/1

111.111.111.111   0   FULL/  -        00:00:34    10.1.1.2        Ethernet1/0

CE4#

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

Things I am not understanding here are the following:

1. I try pinging from CE2/PE4 to 10.1.1.2/10.1.1.1. They dont ping. The other way around(i.e. pinging from CE4 to 10.1.1.33/10.1.1.34 is a no no).

2. As soon as I remove the redistribution of connected routes in BGP address-family ipv4 on PE1 and PE4, I lose connectivity between CEs. The only subnets pinging with the redistribution configured are the connected routes on each CE.

3. Why dont I understand these things!!!!???????? Ive been bugged up and usually I am lazy enough to even create a new post(you might find this is the first post from my end), but things are going really bad around my learning curve lately, so I decided to buckle up and hence ended up with this post(usually I try to figure it out by myself(of course through Brian McGahans blog posts and through great stuff contributed by the other demi-Gods.)

Configs for all the other routers are given below. Please do not bother about the other routers since I have just IPed them, no other useful configuration exists.

37 Replies 37

Peter Paluch
Cisco Employee
Cisco Employee

Hi Arun and Varma,

Please allow me to join the discussion.

One of your earliest posts caught my attention, in particular:

PE4#sh ip cef vrf CE2 30.30.30.30

30.30.30.30/32, version 21, epoch 0, per-destination sharing

0 packets, 0 bytes

  tag information set

    local tag: VPN-route-head

    fast tag rewrite with

        Recursive rewrite via 200.200.200.200/32, tags imposed {26}

  via 200.200.200.200, 0 dependencies, recursive

    next hop 10.1.1.29, Ethernet1/0 via 200.200.200.200/32

    valid adjacency

    tag rewrite with

        Recursive rewrite via 200.200.200.200/32, tags imposed {26}

  Recursive load sharing using 200.200.200.200/32.

PE4#

If I am interpreting this output correctly, the 30.30.30.30/32 network is located at CE4 behind PE1. Furthermore, PE4 and PE1 are not directly connected. We should therefore be seeing two labels here: the top label describing the LSP towards PE1, the bottom label identifying the network 30.30.30.30/32 in the appropriate VRF on PE1. However, there is only a single label indicated here, and that is suspicious. This would be my personal course of action: to determine what does this particular label describe, and why is the second label missing.

Useful commands on PE4:

show ip bgp vpnv4 all labels

show mpls forwarding-table

Best regards,

Peter

So Peter,

Are we referring to the VPN label which is missing?

Ill check that and get back to you.

Hi Peter/Kishore,

Thats so true that I cannot find another label below it.

Output follows:

PE4#sh ip bgp vpnv4 all labels

   Network          Next Hop      In label/Out label

Route Distinguisher: 1:1 (CE2)

   1.1.1.1/32       200.200.200.200 nolabel/20

   10.1.1.0/30      200.200.200.200 nolabel/23

   10.1.1.4/30      200.200.200.200 nolabel/24

   10.1.1.8/30      200.200.200.200 nolabel/21

   10.1.1.32/30     12.12.12.12     17/nolabel

                    0.0.0.0         17/aggregate(CE2)

   11.11.11.0/24    200.200.200.200 nolabel/22

   12.12.12.12/32   12.12.12.12     18/nolabel

   20.20.20.20/32   200.200.200.200 nolabel/33

   30.30.30.30/32   200.200.200.200 nolabel/25

   33.33.33.33/32   200.200.200.200 nolabel/26

   40.40.40.40/32   200.200.200.200 nolabel/34

   50.50.50.50/32   200.200.200.200 nolabel/32

   60.60.60.60/32   200.200.200.200 nolabel/31

   70.70.70.70/32   200.200.200.200 nolabel/30

   80.80.80.80/32   200.200.200.200 nolabel/29

   90.90.90.90/32   200.200.200.200 nolabel/28

   172.19.10.1/32   200.200.200.200 nolabel/36

   172.19.10.2/32   200.200.200.200 nolabel/35

   172.19.10.3/32   200.200.200.200 nolabel/27

   172.19.10.4/32   200.200.200.200 nolabel/37

   172.19.20.0/30   12.12.12.12     19/nolabel

I have a doubt though. Do I need to enable mpls ip on the loopbacks of the PE routers which peer with each other.

Hi Arun

No we do not need to enable mpls on the loopbacks.

Secondly the above output is just showing the VPN labels and not the label stack with transport labels

I just double checked over this using c7200 in Lab. Did you use c3600 in your lab as when we use 3600 the CEF output has different format.

*************

c3600

*********

PE4#sh ip cef vrf CE2 30.30.30.30 detail

30.30.30.30/32, version 8, epoch 0, per-destination sharing

0 packets, 0 bytes

  tag information set

    local tag: VPN-route-head

    fast tag rewrite with

        Recursive rewrite via 200.200.200.200/32, tags imposed {23}

  via 200.200.200.200, 0 dependencies, recursive

    next hop 10.1.1.29, Ethernet1/0 via 200.200.200.200/32

    valid adjacency

    tag rewrite with

        Recursive rewrite via 200.200.200.200/32, tags imposed {23}

  Recursive load sharing using 200.200.200.200/32.

PE4#

PE4#traceroute vrf CE2 30.30.30.30

Type escape sequence to abort.

Tracing the route to 30.30.30.30

  1 10.1.1.29 [MPLS: Labels 17/23 Exp 0] 104 msec 176 msec 84 msec

  2 10.1.1.17 [MPLS: Label 23 Exp 0] 76 msec 104 msec 112 msec

  3 10.1.1.9 64 msec 168 msec 72 msec

  4 10.1.1.1 144 msec *  188 msec

PE4#

PE4#show mpls forwarding-table 200.200.200.200

Local  Outgoing    Prefix            Bytes tag  Outgoing   Next Hop

tag    tag or VC   or Tunnel Id      switched   interface

18     17          200.200.200.200/32   \

                                     0          Et1/0      10.1.1.29

PE4#

********

c7200

*********

PE4#sh ip bgp vpnv4 all labels

   Network          Next Hop      In label/Out label

Route Distinguisher: 1:1 (CE2)

   1.1.1.1/32       200.200.200.200 nolabel/18

   10.1.1.0/30      200.200.200.200 nolabel/21

   10.1.1.8/30      200.200.200.200 nolabel/19

   10.1.1.32/30     12.12.12.12     18/nolabel

                    0.0.0.0         18/nolabel(CE2)

   11.11.11.0/24    200.200.200.200 nolabel/20

   12.12.12.12/32   12.12.12.12     19/nolabel

   30.30.30.30/32   200.200.200.200 nolabel/22

PE4#tr

PE4#traceroute v

PE4#traceroute vrf CE2 11.11.11.11

Type escape sequence to abort.

Tracing the route to 11.11.11.11

  1 10.1.1.29 [MPLS: Labels 16/20 Exp 0] 152 msec 168 msec 84 msec

  2 10.1.1.10 [MPLS: Label 20 Exp 0] 156 msec 108 msec 204 msec

  3 10.1.1.9 164 msec *  112 msec

PE4#traceroute vrf CE2 30.30.30.30

Type escape sequence to abort.

Tracing the route to 30.30.30.30

  1 10.1.1.29 [MPLS: Labels 16/22 Exp 0] 180 msec 144 msec 148 msec

  2 10.1.1.10 [MPLS: Label 22 Exp 0] 132 msec 92 msec 172 msec

  3 10.1.1.9 148 msec 156 msec 84 msec

  4 10.1.1.1 168 msec *  132 msec

PE4#

The issue is somewhere related to an unexpected GNS behaviour nothing much else.

Regards

Varma

Hi Vaibhava,

That is true. I am indeed using a 3640 appliance in GNS.

I tried with 7200 just now. I seem to be getting the same output now.

Thanks everyone. I hope GNS fixes this soon. 7200s running on my i3 with 2GB ram is a big throt

Arun, Vaibhava,

I doubt this is caused by GNS/Dynamips. Internal processes and algorithms embodied in IOS software can not be influenced by GNS/Dynamips. GNS/Dynamips are virtual machines similar to Xen, VMWare or VirtualBox, and they merely reinterpret and execute the code of the IOS, but they can not directly influence how, say, MPLS label bindings are allocated.

That being said, there may be important differences in IOS images themselves pertaining to the output of the show ip cef commands, and that is perhaps what we have observed here.

In any case, this brings us back to the original issue of not being able to achieve a full reachability in Arun's network. I must admit that I am still somewhat confused by the copious outputs of show commands. What I suggest is simply following the path from CE2 to 30.30.30.30 at CE4 and verifying all the necessary control/data plane structures and processes.

Best regards,

Peter

Well Peter,

I dont disagree, and I dont agree completely to the points above. I have tried running my setup with CEs using 3640s and PEs and Ps comprising of 7200s. Much to my dislike, its giving mixed results as given below.

I am not able to understand this. Sorry to bother you all with silly doubts, but thats the way I usually learn.

Please please help.

Issue:

1. Right now, I have configured BGP addr-families in PE1 and PE2 with redistribute connected. In this case,

   I can get a bgp route for the connected subnet across the CEs and can ping the connected subnets. Also, here,

  I am unable to ping CE1 to CE2 subnets(except the connected one) and can ping all subnets from CE2 to      CE1.Same is the case for PE1 to PE2 and vice-versa.

2. As soon as I remove the redistributed connected command, I am unable to ping anything from PE1 to PE2, and PE2 to PE1, and CE1 to CE2 and CE2 to CE1. I get all the other routes other than the connected vrf routes though.

Where am I going wrong.

A gist what I have configured and is as follows:

1. Router (AS2)CE1 - PE1(AS1) - P - PE2 - CE2(AS3)

2. Important parts of the configs are given below:

R6#sh run | sec bgp

redistribute bgp 2 subnets

router bgp 2

no synchronization

bgp log-neighbor-changes

redistribute ospf 100 metric 20

neighbor 10.1.1.2 remote-as 1

neighbor 10.1.1.2 ebgp-multihop 5

neighbor 10.1.1.2 update-source Loopback0

neighbor 10.1.1.2 next-hop-self

no auto-summary

R6#

R6#

R6#

R6#sh run | sec ospf

router ospf 100

log-adjacency-changes

redistribute bgp 2 subnets

network 1.1.1.0 0.0.0.3 area 0

network 10.1.1.0 0.0.0.3 area 0

network 200.200.200.200 0.0.0.0 area 0

redistribute ospf 100 metric 20

R6#

=================================

R7#sh run | sec bgp

router bgp 1

bgp log-neighbor-changes

neighbor 4.4.4.4 remote-as 1

neighbor 4.4.4.4 update-source Loopback0

!

address-family ipv4

  neighbor 4.4.4.4 activate

  neighbor 4.4.4.4 next-hop-self

  no auto-summary

  no synchronization

exit-address-family

!

address-family vpnv4

  neighbor 4.4.4.4 activate

  neighbor 4.4.4.4 send-community extended

exit-address-family

!

address-family ipv4 vrf CE1

  redistribute connected

  neighbor 1.1.1.1 remote-as 2

  neighbor 1.1.1.1 ebgp-multihop 5

  neighbor 1.1.1.1 activate

  neighbor 1.1.1.1 next-hop-self

  no synchronization

exit-address-family

R7#

R7#sh run | sec osp

router ospf 100

log-adjacency-changes

network 2.2.2.2 0.0.0.0 area 0

network 10.1.1.4 0.0.0.3 area 0

R7#

================================

R9(config-router)#do sh run | sec bgp

router bgp 1

no synchronization

bgp log-neighbor-changes

neighbor 2.2.2.2 remote-as 1

neighbor 2.2.2.2 update-source Loopback0

neighbor 2.2.2.2 next-hop-self

no auto-summary

!

address-family vpnv4

  neighbor 2.2.2.2 activate

  neighbor 2.2.2.2 send-community extended

exit-address-family

!

address-family ipv4 vrf CE2

  redistribute connected

  neighbor 5.5.5.5 remote-as 3

  neighbor 5.5.5.5 ebgp-multihop 5

  neighbor 5.5.5.5 activate

  neighbor 5.5.5.5 next-hop-self

  no synchronization

exit-address-family

R9(config-router)#do sh run | sec ospf

router ospf 100

log-adjacency-changes

network 4.4.4.4 0.0.0.0 area 0

network 10.1.1.8 0.0.0.3 area 0

R9(config-router)#

=================================

R10#sh run | sec bgp

redistribute bgp 3 subnets

router bgp 3

no synchronization

bgp log-neighbor-changes

redistribute ospf 100 metric 20

neighbor 10.1.1.13 remote-as 1

neighbor 10.1.1.13 ebgp-multihop 5

neighbor 10.1.1.13 update-source Loopback5

neighbor 10.1.1.13 next-hop-self

no auto-summary

R10#

R10#sh run | sec ospf

router ospf 100

log-adjacency-changes

redistribute bgp 3 subnets

network 50.50.50.50 0.0.0.0 area 0

redistribute ospf 100 metric 20

R10#

====================================

P router R8 is not having much config except OSPf domain and mpls ip and protocol ldp.

====================================

3. Important outputs of routers:

R6#sh ip route

Codes: C - connected, S - static, R - RIP, M - mobile, B - BGP

       D - EIGRP, EX - EIGRP external, O - OSPF, IA - OSPF inter area

       N1 - OSPF NSSA external type 1, N2 - OSPF NSSA external type 2

       E1 - OSPF external type 1, E2 - OSPF external type 2

       i - IS-IS, su - IS-IS summary, L1 - IS-IS level-1, L2 - IS-IS level-2

       ia - IS-IS inter area, * - candidate default, U - per-user static route

       o - ODR, P - periodic downloaded static route

Gateway of last resort is not set

     200.200.200.0/32 is subnetted, 1 subnets

C       200.200.200.200 is directly connected, Loopback1

     1.0.0.0/32 is subnetted, 1 subnets

C       1.1.1.1 is directly connected, Loopback0

     50.0.0.0/32 is subnetted, 1 subnets

B       50.50.50.50 [20/0] via 10.1.1.2, 00:37:03

     10.0.0.0/8 is variably subnetted, 3 subnets, 2 masks

B       10.10.10.10/32 [20/0] via 10.1.1.2, 00:12:30

B       10.1.1.12/30 [20/0] via 10.1.1.2, 00:12:30

C       10.1.1.0/30 is directly connected, Ethernet0/0

R6#

R6#sh ip bgp

BGP table version is 7, local router ID is 200.200.200.200

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

*> 1.1.1.1/32       0.0.0.0                  0         32768 ?

*  10.1.1.0/30      10.1.1.2                 0             0 1 ?

*>                  0.0.0.0                  0         32768 ?

*> 10.1.1.12/30     10.1.1.2                               0 1 ?

*> 10.10.10.10/32   10.1.1.2                               0 1 ?

*> 50.50.50.50/32   10.1.1.2                               0 1 3 ?

*> 200.200.200.200/32

                    0.0.0.0                  0         32768 ?

R6#

==================================================

R7#sh ip route

Codes: C - connected, S - static, R - RIP, M - mobile, B - BGP

       D - EIGRP, EX - EIGRP external, O - OSPF, IA - OSPF inter area

       N1 - OSPF NSSA external type 1, N2 - OSPF NSSA external type 2

       E1 - OSPF external type 1, E2 - OSPF external type 2

       i - IS-IS, su - IS-IS summary, L1 - IS-IS level-1, L2 - IS-IS level-2

       ia - IS-IS inter area, * - candidate default, U - per-user static route

       o - ODR, P - periodic downloaded static route

Gateway of last resort is not set

     2.0.0.0/32 is subnetted, 1 subnets

C       2.2.2.2 is directly connected, Loopback0

     3.0.0.0/32 is subnetted, 1 subnets

O       3.3.3.3 [110/11] via 10.1.1.6, 00:38:11, Ethernet1/1

     4.0.0.0/32 is subnetted, 1 subnets

O       4.4.4.4 [110/21] via 10.1.1.6, 00:38:11, Ethernet1/1

     10.0.0.0/30 is subnetted, 2 subnets

O       10.1.1.8 [110/20] via 10.1.1.6, 00:38:11, Ethernet1/1

C       10.1.1.4 is directly connected, Ethernet1/1

R7#sh ip route vr

R7#sh ip route vrf CE1

Routing Table: CE1

Codes: C - connected, S - static, R - RIP, M - mobile, B - BGP

       D - EIGRP, EX - EIGRP external, O - OSPF, IA - OSPF inter area

       N1 - OSPF NSSA external type 1, N2 - OSPF NSSA external type 2

       E1 - OSPF external type 1, E2 - OSPF external type 2

       i - IS-IS, su - IS-IS summary, L1 - IS-IS level-1, L2 - IS-IS level-2

       ia - IS-IS inter area, * - candidate default, U - per-user static route

       o - ODR, P - periodic downloaded static route

Gateway of last resort is not set

     200.200.200.0/32 is subnetted, 1 subnets

B       200.200.200.200 [20/0] via 1.1.1.1, 00:38:11

     1.0.0.0/32 is subnetted, 1 subnets

S       1.1.1.1 [1/0] via 10.1.1.1, Ethernet1/0

     50.0.0.0/32 is subnetted, 1 subnets

B       50.50.50.50 [200/0] via 4.4.4.4, 00:37:56

     10.0.0.0/8 is variably subnetted, 3 subnets, 2 masks

B       10.10.10.10/32 [200/0] via 4.4.4.4, 00:13:40

B       10.1.1.12/30 [200/0] via 4.4.4.4, 00:13:40

C       10.1.1.0/30 is directly connected, Ethernet1/0

R7#sh ip bg

R7#sh ip bgp vp

R7#sh ip bgp all     

For address family: IPv4 Unicast

For address family: VPNv4 Unicast

BGP table version is 14, local router ID is 2.2.2.2

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

Route Distinguisher: 1:1 (default for vrf CE1)

r> 1.1.1.1/32       1.1.1.1                  0             0 2 ?

*> 10.1.1.0/30      0.0.0.0                  0         32768 ?

*                   1.1.1.1                  0             0 2 ?

*>i10.1.1.12/30     4.4.4.4                  0    100      0 ?

*>i10.10.10.10/32   4.4.4.4                  0    100      0 ?

*>i50.50.50.50/32   4.4.4.4                  0    100      0 3 ?

*> 200.200.200.200/32

                    1.1.1.1                  0             0 2 ?

R7#

R7#sh ip bgp vpnv4 all labels

   Network          Next Hop      In label/Out label

Route Distinguisher: 1:1 (CE1)

   1.1.1.1/32       1.1.1.1         19/nolabel

   10.1.1.0/30      0.0.0.0         20/aggregate(CE1)

                    1.1.1.1         20/aggregate(CE1)

   10.1.1.12/30     4.4.4.4         nolabel/21

   10.10.10.10/32   4.4.4.4         nolabel/20

   50.50.50.50/32   4.4.4.4         nolabel/19

   200.200.200.200/32

                    1.1.1.1         21/nolabel

R7#

===================================================

R9#sh ip route 

Codes: C - connected, S - static, R - RIP, M - mobile, B - BGP

       D - EIGRP, EX - EIGRP external, O - OSPF, IA - OSPF inter area

       N1 - OSPF NSSA external type 1, N2 - OSPF NSSA external type 2

       E1 - OSPF external type 1, E2 - OSPF external type 2

       i - IS-IS, su - IS-IS summary, L1 - IS-IS level-1, L2 - IS-IS level-2

       ia - IS-IS inter area, * - candidate default, U - per-user static route

       o - ODR, P - periodic downloaded static route

Gateway of last resort is not set

     2.0.0.0/32 is subnetted, 1 subnets

O       2.2.2.2 [110/21] via 10.1.1.9, 00:39:31, Ethernet1/0

     3.0.0.0/32 is subnetted, 1 subnets

O       3.3.3.3 [110/11] via 10.1.1.9, 00:39:31, Ethernet1/0

     4.0.0.0/32 is subnetted, 1 subnets

C       4.4.4.4 is directly connected, Loopback0

     10.0.0.0/30 is subnetted, 2 subnets

C       10.1.1.8 is directly connected, Ethernet1/0

O       10.1.1.4 [110/20] via 10.1.1.9, 00:39:31, Ethernet1/0

R9#sh ip route vr

R9#sh ip route vrf CE2

Routing Table: CE2

Codes: C - connected, S - static, R - RIP, M - mobile, B - BGP

       D - EIGRP, EX - EIGRP external, O - OSPF, IA - OSPF inter area

       N1 - OSPF NSSA external type 1, N2 - OSPF NSSA external type 2

       E1 - OSPF external type 1, E2 - OSPF external type 2

       i - IS-IS, su - IS-IS summary, L1 - IS-IS level-1, L2 - IS-IS level-2

       ia - IS-IS inter area, * - candidate default, U - per-user static route

       o - ODR, P - periodic downloaded static route

Gateway of last resort is not set

     200.200.200.0/32 is subnetted, 1 subnets

B       200.200.200.200 [200/0] via 2.2.2.2, 00:39:14

     1.0.0.0/32 is subnetted, 1 subnets

B       1.1.1.1 [200/0] via 2.2.2.2, 00:39:14

     50.0.0.0/32 is subnetted, 1 subnets

B       50.50.50.50 [20/0] via 5.5.5.5, 00:39:26

     5.0.0.0/32 is subnetted, 1 subnets

S       5.5.5.5 [1/0] via 10.1.1.14, Ethernet1/1

     10.0.0.0/8 is variably subnetted, 3 subnets, 2 masks

C       10.10.10.10/32 is directly connected, Loopback2

C       10.1.1.12/30 is directly connected, Ethernet1/1

B       10.1.1.0/30 [200/0] via 2.2.2.2, 00:14:52

R9#sh ip bgp all

For address family: VPNv4 Unicast

BGP table version is 13, local router ID is 4.4.4.4

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

Route Distinguisher: 1:1 (default for vrf CE2)

*>i1.1.1.1/32       2.2.2.2                  0    100      0 2 ?

*>i10.1.1.0/30      2.2.2.2                  0    100      0 ?

*> 10.1.1.12/30     0.0.0.0                  0         32768 ?

*> 10.10.10.10/32   0.0.0.0                  0         32768 ?

*> 50.50.50.50/32   5.5.5.5                  0             0 3 ?

*>i200.200.200.200/32

                    2.2.2.2                  0    100      0 2 ?

R9#sh ip bgp vp

R9#sh ip bgp vpnv4 all lab

R9#sh ip bgp vpnv4 all labels

   Network          Next Hop      In label/Out label

Route Distinguisher: 1:1 (CE2)

   1.1.1.1/32       2.2.2.2         nolabel/19

   10.1.1.0/30      2.2.2.2         nolabel/20

   10.1.1.12/30     0.0.0.0         21/aggregate(CE2)

   10.10.10.10/32   0.0.0.0         20/aggregate(CE2)

   50.50.50.50/32   5.5.5.5         19/nolabel

   200.200.200.200/32

                    2.2.2.2         nolabel/21

==================================================

R10#sh ip route      

Codes: C - connected, S - static, R - RIP, M - mobile, B - BGP

       D - EIGRP, EX - EIGRP external, O - OSPF, IA - OSPF inter area

       N1 - OSPF NSSA external type 1, N2 - OSPF NSSA external type 2

       E1 - OSPF external type 1, E2 - OSPF external type 2

       i - IS-IS, su - IS-IS summary, L1 - IS-IS level-1, L2 - IS-IS level-2

       ia - IS-IS inter area, * - candidate default, U - per-user static route

       o - ODR, P - periodic downloaded static route

Gateway of last resort is not set

     200.200.200.0/32 is subnetted, 1 subnets

B       200.200.200.200 [20/0] via 10.1.1.13, 00:39:49

     1.0.0.0/32 is subnetted, 1 subnets

B       1.1.1.1 [20/0] via 10.1.1.13, 00:39:49

     50.0.0.0/32 is subnetted, 1 subnets

C       50.50.50.50 is directly connected, Loopback1

     5.0.0.0/32 is subnetted, 1 subnets

C       5.5.5.5 is directly connected, Loopback5

     10.0.0.0/8 is variably subnetted, 3 subnets, 2 masks

B       10.10.10.10/32 [20/0] via 10.1.1.13, 00:15:42

C       10.1.1.12/30 is directly connected, Ethernet0/0

B       10.1.1.0/30 [20/0] via 10.1.1.13, 00:15:11

R10#

R10#

R10#

R10#sh ip bgp   

BGP table version is 9, local router ID is 50.50.50.50

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

*> 1.1.1.1/32       10.1.1.13                              0 1 2 ?

*> 10.1.1.0/30      10.1.1.13                              0 1 ?

r> 10.1.1.12/30     10.1.1.13                0             0 1 ?

*> 10.10.10.10/32   10.1.1.13                0             0 1 ?

*> 50.50.50.50/32   0.0.0.0                  0         32768 ?

*> 200.200.200.200/32

                    10.1.1.13                              0 1 2 ?

============================================================

AFTER I REMOVE THE REDISTRIBUTE COMMAND:

R7#sh ip bgp all

For address family: IPv4 Unicast

For address family: VPNv4 Unicast

BGP table version is 18, local router ID is 2.2.2.2

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

Route Distinguisher: 1:1 (default for vrf CE1)

r> 1.1.1.1/32       1.1.1.1                  0             0 2 ?

r> 10.1.1.0/30      1.1.1.1                  0             0 2 ?

*>i50.50.50.50/32   4.4.4.4                  0    100      0 3 ?

*> 200.200.200.200/32

                    1.1.1.1                  0             0 2 ?

R7#

R7#sh ip route vr

R7#sh ip route vrf CE1

Routing Table: CE1

Codes: C - connected, S - static, R - RIP, M - mobile, B - BGP

       D - EIGRP, EX - EIGRP external, O - OSPF, IA - OSPF inter area

       N1 - OSPF NSSA external type 1, N2 - OSPF NSSA external type 2

       E1 - OSPF external type 1, E2 - OSPF external type 2

       i - IS-IS, su - IS-IS summary, L1 - IS-IS level-1, L2 - IS-IS level-2

       ia - IS-IS inter area, * - candidate default, U - per-user static route

       o - ODR, P - periodic downloaded static route

Gateway of last resort is not set

     200.200.200.0/32 is subnetted, 1 subnets

B       200.200.200.200 [20/0] via 1.1.1.1, 00:58:03

     1.0.0.0/32 is subnetted, 1 subnets

S       1.1.1.1 [1/0] via 10.1.1.1, Ethernet1/0

     50.0.0.0/32 is subnetted, 1 subnets

B       50.50.50.50 [200/0] via 4.4.4.4, 00:57:48

     10.0.0.0/30 is subnetted, 1 subnets

C       10.1.1.0 is directly connected, Ethernet1/0-------------> I dont find the route to PE2 connected route here.

R7#

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

R9#sh ip bgp all

For address family: VPNv4 Unicast

BGP table version is 16, local router ID is 4.4.4.4

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

Route Distinguisher: 1:1 (default for vrf CE2)

*>i1.1.1.1/32       2.2.2.2                  0    100      0 2 ?

*>i10.1.1.0/30      2.2.2.2                  0    100      0 2 ?

*> 50.50.50.50/32   5.5.5.5                  0             0 3 ?

*>i200.200.200.200/32

                    2.2.2.2                  0    100      0 2 ?

R9#sh ip route vr

R9#sh ip route vrf CE2

Routing Table: CE2

Codes: C - connected, S - static, R - RIP, M - mobile, B - BGP

       D - EIGRP, EX - EIGRP external, O - OSPF, IA - OSPF inter area

       N1 - OSPF NSSA external type 1, N2 - OSPF NSSA external type 2

       E1 - OSPF external type 1, E2 - OSPF external type 2

       i - IS-IS, su - IS-IS summary, L1 - IS-IS level-1, L2 - IS-IS level-2

       ia - IS-IS inter area, * - candidate default, U - per-user static route

       o - ODR, P - periodic downloaded static route

Gateway of last resort is not set

     200.200.200.0/32 is subnetted, 1 subnets

B       200.200.200.200 [200/0] via 2.2.2.2, 00:58:26

     1.0.0.0/32 is subnetted, 1 subnets

B       1.1.1.1 [200/0] via 2.2.2.2, 00:58:26

     50.0.0.0/32 is subnetted, 1 subnets

B       50.50.50.50 [20/0] via 5.5.5.5, 00:58:38

     5.0.0.0/32 is subnetted, 1 subnets

S       5.5.5.5 [1/0] via 10.1.1.14, Ethernet1/1

     10.0.0.0/8 is variably subnetted, 3 subnets, 2 masks

C       10.10.10.10/32 is directly connected, Loopback2

C       10.1.1.12/30 is directly connected, Ethernet1/1

B       10.1.1.0/30 [200/0] via 2.2.2.2, 00:13:02----------------------------------------> I get this route here, but the route 10.1.1.12/30 is missing in PE1 vrf CE1.

R9#

Guys,

I think I figured out the problem here.

If you see the above set of commands on R10, we can see I have not advertised 5.5.5.5 through OSPF.

At this juncture, none of the prefixes in CE2 are ping"able" from CE1.

As soon as I advertised 5.5.5.5, all the routes started pinging.

Peter: I dont know, but I really think there is some issue with my laptop or GNS as shown by this behaviour.

Output attached as I had done:

And now I will again remove the 5.5.5.5 advertisement in OSPF. See what happens:

Case closed???

Arun,

I apologize for not replying - I've had a busy week. Let me recatch what has been done so far and I will reply in a couple of hours.

Best regards,

Peter

Hi Peter/Vaibhava/Kishore,

Needless to say, these types of scenarios when repeatedly implemented by me in GNS is causing the same issue.

I have to find a way around. Is there any way I can make this network "WORK?"

Ill just do one thing. If you guys could help me to figure out the issue by taking out some time from your tea break, Id like to post the topology and all the associated files. You just need to download this and run this in GNS.

Please help.

Guys,

The configuration that I have now attached with this particular post is a working configuration, as I wanted it to be.

Basically I modified the configuration to  include a /32 loopback in the global routing table for both the PEs, and ran bgp peering using these loopbacks. Rest is all the same, except that I redistributed the loopbacks under bgp address-family ipv4 vrf cust.

Please help me to understand where am I going wrong with my concepts?

Hi Arun

Whats the issue with this new topology configuration ?

Regards

Varma

Hi Vaibhava,

See, I have attached two versions of the topology(1st one is the one that is not working and the 2nd one is the one that is working).

Changes made:

1. In the 1st version, I was peering over MP-BGP using the connected interfaces of the PE routers pointing to the P router.

2. In the 2nd version, I am peering using /32 loopbacks of the PEs that I newly created( not in vrf but in Global table) and it       is working.

I do not understand what difference does it make if I peer using loopback /32 instead of P2P. Also, I can see two labels on prefixes when I use loopbacks to peer instead of the 1 label I find when using P2P for peering MP-BGP.

Hi Arun

I did review the two topologies and from my understanding below is what is happening:

When we are using the physical interface for MP-iBGP Peering then the Peer IP is not learnt as a X /32 but instead as

a X /30 and hence the LSP breaks for the MP-iBGP Peer IP as there is no Label for X/32 but instead for a X /30 ..This is the reason that routes are populating but no traffic forwarding happens as the Transport Label is missing here...

This is similar to case whereby the MPLS LSP breaks due to summarization of Loopback IPs..

In the 2nd case we had MPLS Label for the X /32 MP-iBGP Peer IP and hence both the labels....

This is from my understanding whats happening here and obstructing the traffic flow in Case I....

Hope this provides some insight into the issue...

Regards

Varma

If I may add my thoughts here. Varma is absolutely correct.

In other words, the control plane works fine but the data plane doesn't

There is a lot emphasis on the X/32 in MPLS.  LDP adds labels to every route learned from the IGP in the RIB so in a large MPLS backbone you end up seeing tons of X/30's which are the physical interfaces that connect the PE's P's etc. There are mechanisms to actually just learn the host routes (i.e) X/32 only as well. for eg: the command mpls ldp label allocate global host-routes.This allocates labels only to the loopbacks which are required for your LSP. 

In most layer3 VPN configurations, only the LSP's created to reach the X/32 hosts or BGP next hops between the PE routers carry traffic and are relevant to the L3 VPN's. Also make sure you just dont use loopback's but also allocate /32 addresses to them

I will try and reply in another post to another problem of yours which you posted earlier Oct 25, 2011 11:19 PM

HTH

Kishore

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