[c-nsp] OSPF inside VRF - Cisco Juniper Interoperability

[Junaid]

Hi,

I am caught up in what seems to be a Juniper Cisco interoperability
issue. I am running OSPF with customer inside VRF. Topology is
something like the following:

CE1 ---[Area 0]--- PE1 ---- P1 --- P2 --- PE2 ---[Area 6]--- CE2

The two P routers are acting as route reflectors.

CE1, CE2 and PE1 are Cisco devices while rest are Juniper M-series
routers. The problem I am facing is that CE1 routes received at CE2
are Inter-area which is what is required (no redistribution into OSPF
is done on CE1 and CE2). However, CE2 routes received by CE1 are Type
5 (E1). The documentation states that inorder to preserve the route
types, domain IDs should be same on both PE routers. I have set domain
ID to be 1.1.1.1:512, this was done on cisco via the command:
"domain-id type 0105 value 010101010200" and on juniper as: "domain-id
1.1.1.1:512" in the OSPF configuration inside the VRF. Also on Juniper
the domain-id was added into the ospf routes when redistributing them
into MBGP.

The problem seems to be with the Cisco PE1 router that can't seem to
interpret the route-type attribute generated by Juniper (seen in the
output as 0x306:0:393472):

PE1#sh ip bgp vpnv4 all 10.254.20.254
BGP routing table entry for 1:103:10.254.20.254/32, version 550
Paths: (1 available, best #1, table VPN_OSPF)
 Not advertised to any peer
 Local
   <PE2_Loopback_IP> (metric 4) from <P1_Loopback_IP> (<P1_Loopback_IP>)
     Origin IGP, metric 2, localpref 100, valid, internal, best
     Extended Community: RT:1:103 OSPF DOMAIN
ID:0x0105:0x010101010200 0x306:0:393472

10.254.20.254/32 is advertised by CE2 (assigned on one of its loopback
interfaces). Now the domain ID is fine but it seems that Cisco is
unable to interpret the route-type attribute. 393472 translates to
60100 where 6 is the area ID, 01 says that it is type 1 LSA and and
last two bytes are options are not used in this case. Upon receiving
this route via MBPG, PE1 injects a type 5 LSA towards CE1 (confirmed
on CE1 by enabling debugging) where it should inject have injected
type 3:

OSPF: Ack Type 5, LSID 10.254.20.254, Adv rtr 10.254.1.1, age 5, seq 0x80000001


If I replace the Juniper PE2 with a Cisco then on PE1 seems to
interpret the route-type attribute correctly (OSPF RT:0.0.0.6:2:0) and
inject type 3 LSA
towards CE1 and CE1 receive the routes as inter-area:

PE1#sh ip bgp vpnv4 all 10.254.20.254
BGP routing table entry for 1:103:10.254.20.254/32, version 676
Paths: (1 available, best #1, table VPN_OSPF)
 Not advertised to any peer
 Local
   <PE2_Loopback_IP> (metric 2) from <P1_Loopback_IP> (<P1_Loopback_IP>)
     Origin incomplete, metric 11112, localpref 100, valid, internal, best
     Extended Community: RT:1:103 OSPF DOMAIN
ID:0x0005:0x010101010200 OSPF RT:0.0.0.6:2:0 OSPF ROUTER
ID:10.254.2.1:512


Debug output:

OSPF: Ack Type 3, LSID 10.254.20.254, Adv rtr 10.254.1.1, age 1, seq 0x80000001

Any idea what is causing this behavior? Any solution? Will appreciate any help.


Regards,
Junaid