IP unnumbered + ISIS + BGP + MPLS

[Rob85]

Hi all,

I'm troubleshooting a setup between two routers R1 and R2. Both are using ip unnumbered with ISIS to distribute their loopback address.

BGP and MPLS are configured to distribute their connected loopback and subinterface into VRF quarantaine.

I see that the routes are installed in the VRF table, but they're not pingable.

Suggestions?

hostname R1

ip vrf quarantaine
 rd 65000:250
 route-target export 65000:250
 route-target import 65000:250
!
interface Loopback0
 no shutdown
 ip address 10.0.1.1 255.255.255.255
 ip router isis 
!
interface Loopback250
 no shutdown
 ip vrf forwarding quarantaine
 ip address 1.1.1.1 255.255.255.255
!
interface GigabitEthernet1
 no shutdown
 ip unnumbered Loopback0
 ip router isis 
 negotiation auto
 medium p2p
 mpls ip
 no mop enabled
 no mop sysid
!
interface GigabitEthernet8
 no shutdown
 no ip address
 negotiation auto
 no mop enabled
 no mop sysid

!
interface GigabitEthernet8.250
 no shutdown
 encapsulation dot1Q 250 native
 ip vrf forwarding quarantaine

 ip address 10.101.250.1 255.255.255.0

!
router isis
 net 49.0001.0000.0000.0008.00
 metric-style narrow
 mpls ldp sync
!
router bgp 65000
 !
 bgp router-id interface Loopback0
 bgp log-neighbor-changes
 no bgp default ipv4-unicast
 neighbor 10.0.1.2 remote-as 65000
 neighbor 10.0.1.2 update-source Loopback0
 !
 address-family vpnv4
  neighbor 10.0.1.2 activate
  neighbor 10.0.1.2 send-community extended
 exit-address-family
 !
 address-family ipv4 vrf quarantaine
  redistribute connected
 exit-address-family

R2:

hostname R2
!
ip vrf quarantaine
 rd 65000:250
 route-target export 65000:250
 route-target import 65000:250
!
interface Loopback0
 no shutdown
 ip address 10.0.1.2 255.255.255.255
 ip router isis 
!
interface Loopback250
 no shutdown
 ip vrf forwarding quarantaine
 ip address 2.2.2.2 255.255.255.255
!
interface GigabitEthernet1
 no shutdown
 ip unnumbered Loopback0
 ip router isis 
 negotiation auto
 medium p2p
 mpls ip
 no mop enabled
 no mop sysid
!
interface GigabitEthernet8
 no shutdown
 no ip address
 negotiation auto
 no mop enabled
 no mop sysid
!
interface GigabitEthernet8.250
 no shutdown
 encapsulation dot1Q 250 native
 ip vrf forwarding quarantaine
 ip address 10.102.250.1 255.255.255.0
!
router isis
 net 49.0001.0000.0000.0010.00
 metric-style narrow
 mpls ldp sync
!
router bgp 65000

 bgp router-id interface Loopback0
 bgp log-neighbor-changes
 no bgp default ipv4-unicast
 neighbor 10.0.1.1 remote-as 65000
 neighbor 10.0.1.1 update-source Loopback0
 !
 address-family vpnv4
  neighbor 10.0.1.1 activate
  neighbor 10.0.1.1 send-community extended
 exit-address-family
 !
 address-family ipv4 vrf quarantaine
  redistribute connected
 exit-address-family

[MHM Cisco World]

interface GigabitEthernet1
 no shutdown
 ip unnumbered Loopback0<<- use IP instead of unnumbered Loopback, note that delete remove LOOPBACK0 or change the config of BGP are config are right except this point.
 ip router isis 
 negotiation auto
 medium p2p
 mpls ip
 no mop enabled
 no mop sysid

[Harold Ritter · Accepted solution]

Hi @Rob85 ,

Just remove the "medium p2p" from GI1 on both sides. It should fix it.

Regards,

[Rob85]

You're correct. Good catch.. it slipt into my "getting ISIS with ip unnumbered to work" config snip.

With this setup you can connect all sort of routers in various topologies. Now I need to tweak on the BGP settings, but the general contruct is working now. Thanks!