Hi, Experts
Equipment: Cisco ASR9922, IOS-XR 4.3.2
Issue: I have problem that my RR do the next-hop-self by using route-policy for client routers, the next-hop is changed as intended but the MPLS label doesn’t changed to reflect the new next-hop.
What I would like to achieve: I would like RR to set next-hop-self only for selected prefixes(172.168.0.0/24, 0.0.0.0/0) but maintain original next-hop for the rest, I do this by using route-policy.
Detail:
I have routers running MPLS infrastructure with ASR9922 as an RR. RN router is in neighbor-group RN and CPE-xx routers are in neighbor-group AN.
- •- Every routers are in same BGP AS64549.
- •- RN sends prefixes 0.0.0.0/0 and 172.168.0.0/24 to RR.
- •- CPE-25 sends prefix 192.168.25.1/32 to RR.
Neighbor-group AN has the route-policy AN-OUT2 to set next-hop of prefix 172.168.0.0/24 and 0.0.0.0/0 to RR#loopback1 before send out update to CPE routers. Below is BGP and RPL configuration at RR.
router bgp 64549
nsr
bgp graceful-restart
ibgp policy out enforce-modifications
address-family vpnv4 unicast
additional-paths receive
additional-paths send
additional-paths selection route-policy ADD-PATH-iBGP
retain route-target all
!
neighbor-group AN
remote-as 64549
cluster-id 172.16.1.11
update-source Loopback1
address-family vpnv4 unicast
route-reflector-client
route-policy AN-OUT2 out
soft-reconfiguration inbound
!
!
route-policy AN-OUT2
if destination in DEFAULT or destination in RNC then
set next-hop 192.168.10.11
else
pass
endif
end-policy
This is what RR advertises to CPE-24
RP/0/RP0/CPU0:RR#show bgp vpnv4 unicast neighbors 192.168.10.24 advertised-routes
Fri Dec 20 15:23:14.931 BKK
Network Next Hop From AS Path
Route Distinguisher: 64549:3339
0.0.0.0/0 192.168.10.11 172.16.1.1 ?
172.16.1.2 ?
172.168.0.0/24 192.168.10.11 172.16.1.1 ?
172.16.1.2 ?
192.168.0.1/32 192.168.10.11 192.168.10.24 i
192.168.0.26/32 192.168.10.26 192.168.10.26 i
192.168.25.1/32 192.168.10.25 192.168.10.25 i
192.168.211.8/30 192.168.10.22 192.168.10.22 i
The IP part works as intended but MPLS Label doesn’t work as intended. Please take a look at RN who is originates 172.168.0.0/24, label 16025 is locally assigned.
RP/0/RP0/CPU0:RN1#show bgp vpnv4 unicast labels
Status codes: s suppressed, d damped, h history, * valid, > best
i - internal, r RIB-failure, S stale, N Nexthop-discard
Origin codes: i - IGP, e - EGP, ? - incomplete
Network Next Hop Rcvd Label Local Label
Route Distinguisher: 64549:3339 (default for vrf VLAN3339)
*> 0.0.0.0/0 0.0.0.0 nolabel 16025
* i 172.16.1.11 16068 16025
* i 172.16.1.13 16033 16025
*> 172.168.0.0/24 0.0.0.0 nolabel 16025
* i 172.16.1.11 16059 16025
* i 172.16.1.13 16024 16025
172.168.0.0/24 at RR, label 16059 is locally assigned, label 16025 is receive from RN router. It should send 172.168.0.0/24 with label 16059 to CPE-24 to reflect next-hop changed.
RP/0/RSP0/CPU0:RR#show bgp vpnv4 unicast labels
Status codes: s suppressed, d damped, h history, * valid, > best
i - internal, r RIB-failure, S stale, N Nexthop-discard
Origin codes: i - IGP, e - EGP, ? - incomplete
Network Next Hop Rcvd Label Local Label
Route Distinguisher: 64549:3339
*>i0.0.0.0/0 172.16.1.1 16025 16068
* i 172.16.1.2 16007 16068
*>i172.168.0.0/24 172.16.1.1 16025 16059
* i 172.16.1.2 16007 16059
*>i192.168.0.1/32 192.168.10.24 131070 16060
*>i192.168.25.1/32 192.168.10.25 131070 16062
*>i192.168.211.8/30 192.168.10.22 131070 16065
What I found at CPE-24 which is Alcatel router is that, RR send prefix 172.168.0.0/24, nh 192.168.10.11 with label 16025 which is incorrect.
A:CPE-24# show router bgp routes vpn-ipv4 172.168.0.0/24
===============================================================================
BGP Router ID:192.168.10.24 AS:64549 Local AS:64549
===============================================================================
Legend -
Status codes : u - used, s - suppressed, h - history, d - decayed, * - valid
Origin codes : i - IGP, e - EGP, ? - incomplete, > - best, b - backup
===============================================================================
BGP VPN-IPv4 Routes
===============================================================================
Flag Network LocalPref MED
Nexthop Path-Id VPNLabel
As-Path
-------------------------------------------------------------------------------
u*>? 64549:3339:172.168.0.0/24 100 0
192.168.10.11 None 16025
No As-Path
-------------------------------------------------------------------------------
Routes : 1
===============================================================================
On RR If I just remove the policy and do the next-hop-self under vpv4 address family, CPE-24 will get corrent nh with correct label(16059) but that won’t achieve our requirement to change nh only on selected prefixes. Is this software problem? Or is there any solution to work around?
Regard,
Marit
