MVPN Extranet difference between IOS 12.2SX and 15.1SY

Dmitry Filchakov · ‎08-20-2015

Hello community!

I'm preparing to migrate on our Cat6500 from IOS 12.2SXI13 to the latest 15.1SY and i find a problem with MVPN Extranet Support.

With the totally the same configuration under 12.2 MVPN Extranet works fine, but under 15.1 it doesn't withour some additional config (see below). We using the source MVRF on the receiver PE (Option 2).

Multicast source PE:

interface Loopback1
description Loopback for VRF iTV PIM RP
ip vrf forwarding iTV
ip address 212.49.127.127 255.255.255.255
no ip redirects
no ip unreachables
no ip proxy-arp
ip pim sparse-mode
!
ip vrf iTV
rd 12668:20
route-target export 12668:20
route-target import 12668:20
mdt default 232.255.255.20
mdt data 232.255.20.0 0.0.0.255
!
router bgp 12668
!
address-family ipv4 vrf iTV
redistribute connected metric 0
redistribute static metric 0
no synchronization
network 212.49.127.0
exit-address-family
!
ip route vrf iTV 212.49.127.0 255.255.255.0 Null0
!
ip multicast-routing
ip pim ssm default
ip multicast-routing vrf iTV
ip pim vrf iTV rp-address 212.49.127.127
!
end
!
Receiver PE:

ip vrf iTV
rd 12668:20
route-target export 12668:20
route-target import 12668:20
mdt default 232.255.255.20
!
!
router bgp 12668
!
address-family ipv4 vrf iTV
redistribute connected metric 0
redistribute static metric 0
no synchronization
exit-address-family
!
ip multicast-routing
ip pim ssm default
ip multicast-routing vrf iTV
ip pim vrf iTV rp-address 212.49.127.127
!
vrf definition Inet
rd 12668:10
route-target export 12668:10
route-target import 12668:10
route-target import 12668:20
!
address-family ipv4
exit-address-family
!
address-family ipv6
exit-address-family
!
router bgp 12668
!
address-family ipv4 vrf Inet
redistribute connected metric 0
redistribute static metric 0
no synchronization
exit-address-family
!
ip multicast-routing vrf Inet
ip pim vrf Inet rp-address 212.49.127.127
!
end

I have receiver in vrf Inet for group 239.255.2.122:

sh ip igmp vrf Inet groups 239.255.2.122
IGMP Connected Group Membership
Group Address Interface Uptime Expires Last Reporter Group Accounted
239.255.2.122 Vlan3303 01:10:08 00:02:31 169.254.106.34

But i don't see (S,G) entry for this group:

sh ip mroute vrf Inet 239.255.2.122
Load for five secs: 12%/3%; one minute: 7%; five minutes: 6%
Time source is NTP, 17:44:32.284 Ural Thu Aug 20 2015

IP Multicast Routing Table
Flags: D - Dense, S - Sparse, B - Bidir Group, s - SSM Group, C - Connected,
L - Local, P - Pruned, R - RP-bit set, F - Register flag,
T - SPT-bit set, J - Join SPT, M - MSDP created entry, E - Extranet,
X - Proxy Join Timer Running, A - Candidate for MSDP Advertisement,
U - URD, I - Received Source Specific Host Report,
Z - Multicast Tunnel, z - MDT-data group sender,
Y - Joined MDT-data group, y - Sending to MDT-data group,
G - Received BGP C-Mroute, g - Sent BGP C-Mroute,
Q - Received BGP S-A Route, q - Sent BGP S-A Route,
V - RD & Vector, v - Vector
Outgoing interface flags: H - Hardware switched, A - Assert winner
Timers: Uptime/Expires
Interface state: Interface, Next-Hop or VCD, State/Mode

(*, 239.255.2.122), 00:00:32/00:02:27, RP 212.49.127.127, flags: SJC
Incoming interface: Null, RPF nbr 0.0.0.0
Outgoing interface list:
Vlan3303, Forward/Sparse, 00:00:32/00:02:27

sh ip mroute vrf iTV 239.255.2.122
Group 239.255.2.122 not found

Multicast senders in vrf iTV and using 212.49.127.0/24 subnet. Something wrong with RPF here:
sh ip rpf vrf Inet 212.49.127.0
failed, no route exists

But in unicast routing table all necessary routes is present:
sh ip route vrf Inet 212.49.127.0
Routing Table: Inet
Routing entry for 212.49.127.0/24, 49 known subnets
Variably subnetted with 3 masks
B 212.49.127.0/24 [200/1500] via 212.49.96.12, 00:00:12
B 212.49.127.12/30 [200/1500] via 212.49.96.12, 00:00:12
B 212.49.127.16/30 [200/1500] via 212.49.96.12, 00:00:12
B 212.49.127.24/30 [200/1500] via 212.49.96.12, 00:00:12
B 212.49.127.28/30 [200/1500] via 212.49.96.12, 00:00:12
....

If i use RPF for MVPN Extranet Support Using Static Mroutes (ip mroute vrf Inet 212.49.127.0 255.255.255.0 fallback-lookup vrf iTV) or Multicast VPN Extranet VRF Select (ip multicast vrf Inet rpf select vrf iTV group-list XXX) all works fine.
But if i use the source MVRF on the receiver PE router (Option 2) for extranet links no additional configuration is required for RPF resolution...

Also i found one more workaround - just put MDT default config under receiver VRF. But why i need to do this? All my senders in VRF iTV, VRF Inet just for delivering multicast traffic to the end instance. So i don't need additional unnecessary MDT default traffic in VRF Inet.

If i reload Cat6500 to 12.2SXI13 all works good without any MDT defaults in a receiver VRF (Inet), static mroutes and Extranet VRF Selection:

sh ip mroute vrf Inet 239.255.2.122
IP Multicast Routing Table
Flags: D - Dense, S - Sparse, B - Bidir Group, s - SSM Group, C - Connected,
L - Local, P - Pruned, R - RP-bit set, F - Register flag,
T - SPT-bit set, J - Join SPT, M - MSDP created entry, E - Extranet,
X - Proxy Join Timer Running, A - Candidate for MSDP Advertisement,
U - URD, I - Received Source Specific Host Report,
Z - Multicast Tunnel, z - MDT-data group sender,
Y - Joined MDT-data group, y - Sending to MDT-data group
V - RD & Vector, v - Vector
Outgoing interface flags: H - Hardware switched, A - Assert winner
Timers: Uptime/Expires
Interface state: Interface, Next-Hop or VCD, State/Mode

(*, 239.255.2.122), 1w4d/stopped, RP 212.49.127.127, flags: SJC
Incoming interface: Tunnel0, RPF nbr 212.49.96.12, using vrf iTV, RPF-MFD
Outgoing interface list:
Vlan3372, Forward/Sparse, 00:01:16/00:02:45, H
Vlan3373, Forward/Sparse, 00:03:10/00:02:42, H
Vlan3375, Forward/Sparse, 00:05:01/00:02:39, H
Vlan3327, Forward/Sparse, 00:17:12/00:02:43, H
Vlan3331, Forward/Sparse, 00:28:04/00:02:44, H
Vlan3380, Forward/Sparse, 00:53:41/00:02:39, H
Vlan3357, Forward/Sparse, 00:57:41/00:02:57, H
Vlan3390, Forward/Sparse, 01:04:13/00:02:58, H
Vlan3365, Forward/Sparse, 09:41:17/00:02:46, H
Vlan3304, Forward/Sparse, 11:01:51/00:02:59, H
Vlan3358, Forward/Sparse, 3d10h/00:02:44, H

(212.49.127.18, 239.255.2.122), 1w4d/stopped, flags:
Incoming interface: Tunnel0, RPF nbr 212.49.96.12, using vrf iTV, RPF-MFD
Outgoing interface list:
Vlan3372, Forward/Sparse, 00:01:16/00:02:45, H
Vlan3373, Forward/Sparse, 00:03:10/00:02:42, H
Vlan3375, Forward/Sparse, 00:05:01/00:02:39, H
Vlan3327, Forward/Sparse, 00:17:12/00:02:43, H
Vlan3331, Forward/Sparse, 00:28:04/00:02:44, H
Vlan3380, Forward/Sparse, 00:53:41/00:02:39, H
Vlan3357, Forward/Sparse, 00:57:41/00:02:57, H
Vlan3390, Forward/Sparse, 01:04:13/00:02:58, H
Vlan3365, Forward/Sparse, 09:41:17/00:02:46, H
Vlan3304, Forward/Sparse, 11:01:51/00:02:59, H
Vlan3358, Forward/Sparse, 3d10h/00:02:44, H

sh ip mroute vrf iTV 239.255.2.122
IP Multicast Routing Table
Flags: D - Dense, S - Sparse, B - Bidir Group, s - SSM Group, C - Connected,
L - Local, P - Pruned, R - RP-bit set, F - Register flag,
T - SPT-bit set, J - Join SPT, M - MSDP created entry, E - Extranet,
X - Proxy Join Timer Running, A - Candidate for MSDP Advertisement,
U - URD, I - Received Source Specific Host Report,
Z - Multicast Tunnel, z - MDT-data group sender,
Y - Joined MDT-data group, y - Sending to MDT-data group
V - RD & Vector, v - Vector
Outgoing interface flags: H - Hardware switched, A - Assert winner
Timers: Uptime/Expires
Interface state: Interface, Next-Hop or VCD, State/Mode

(*, 239.255.2.122), 7w0d/stopped, RP 212.49.127.127, flags: SJCE
Incoming interface: Tunnel0, RPF nbr 212.49.96.12, Partial-SC
Outgoing interface list: Null

Extranet receivers in vrf Inet:
(*, 239.255.2.122), 1w4d/stopped, RP 212.49.127.127, OIF count: 11, flags: SJC

(212.49.127.18, 239.255.2.122), 7w0d/00:02:59, flags: TYE
Incoming interface: Tunnel0, RPF nbr 212.49.96.12, RPF-MFD, MDT:[212.49.96.12,232.255.20.185]/00:02:03
Outgoing interface list: Null

Extranet receivers in vrf Inet:
(212.49.127.18, 239.255.2.122), 1w4d/00:02:50, OIF count: 11, flags:

sh ip rpf vrf Inet 212.49.127.0
RPF information for ? (212.49.127.0)
RPF interface: Tunnel0
RPF neighbor: ? (212.49.96.12)
RPF route/mask: 212.49.127.0/24
RPF type: unicast (bgp 12668)
RPF recursion count: 0
Doing distance-preferred lookups across tables
BGP originator: 212.49.96.12

I did't post all configuration like "address-family ipv4 mdt", interface config and etc because it is very big output...
Anyone have the same issue? Do you know about different RPF behaviour with MVPN Extranet between 12.2 and 15.1 (i tried 15.1(1)SY5/SY4/SY3 and 15.1(2)SY5/SY4)?

Thanks in advance!