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Bronze

mobility groups with multicast - 7.4.100.60

Hello all,

I am not sure if this is a bug, but here we go. I configured 2 controllers in a mobility group using multicast signalling.

I expect that from the moment i enable multicast, the controller joins this group AND STAYS IN THIS GROUP so he will get messages from all other controllers.

On the first hop router, i can see the join:

#sh ip igmp mem 239.194.248.10

Flags: A  - aggregate, T - tracked

       L  - Local, S - static, V - virtual, R - Reported through v3

       I - v3lite, U - Urd, M - SSM (S,G) channel

       1,2,3 - The version of IGMP, the group is in

Channel/Group-Flags:

       / - Filtering entry (Exclude mode (S,G), Include mode (G))

Reporter:

       <mac-or-ip-address> - last reporter if group is not explicitly tracked

       <n>/<m>      - <n> reporter in include mode, <m> reporter in exclude

Channel/Group                  Reporter        Uptime   Exp.  Flags  Interface

*,239.194.248.10               10.102.78.98    00:00:05 02:54 2A     Vl350

However, this entry does not get refreshed. I have the impression that the controller does not reply to the IGMP general queries:

IGMP(0): Send v2 general Query on Vlan350 -> no replies

#sh ip igmp mem 239.194.248.10

Flags: A  - aggregate, T - tracked

       L  - Local, S - static, V - virtual, R - Reported through v3

       I - v3lite, U - Urd, M - SSM (S,G) channel

       1,2,3 - The version of IGMP, the group is in

Channel/Group-Flags:

       / - Filtering entry (Exclude mode (S,G), Include mode (G))

Reporter:

       <mac-or-ip-address> - last reporter if group is not explicitly tracked

       <n>/<m>      - <n> reporter in include mode, <m> reporter in exclude

Channel/Group                  Reporter        Uptime   Exp.  Flags  Interface

*,239.194.248.10               10.102.78.98    00:02:35 00:24 2A     Vl350

>> 20 seconds from expiry.

#sh ip igmp mem 239.194.248.10

Flags: A  - aggregate, T - tracked

       L  - Local, S - static, V - virtual, R - Reported through v3

       I - v3lite, U - Urd, M - SSM (S,G) channel

       1,2,3 - The version of IGMP, the group is in

Channel/Group-Flags:

       / - Filtering entry (Exclude mode (S,G), Include mode (G))

Reporter:

       <mac-or-ip-address> - last reporter if group is not explicitly tracked

       <n>/<m>      - <n> reporter in include mode, <m> reporter in exclude

Channel/Group                  Reporter        Uptime   Exp.  Flags  Interface

>> 20 seconds later, gone

>> At this moment the controller doesn't receive any messages anymore from remote controllers:

>>sh ip mroute 239.194.248.10 

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

(*, 239.194.248.10), 00:05:38/00:00:21, RP 10.102.90.20, flags: SP

  Incoming interface: Port-channel30, RPF nbr 10.102.78.13, RPF-MFD

Outgoing interface list: Null

This is seen on 8500 platform running 7.4.100.60

We have also WISMs running at 7.0.230.0, and there it can be seen that the entry refreshes every minute (like it should be)

IGMP(0): Received v2 Report on Vlan950 from 10.96.9.67 for 239.194.240.1

IGMP(0): Received Group record for group 239.194.240.1, mode 2 from 10.96.9.67 for 0 sources

IGMP(0): Updating EXCLUDE group timer for 239.194.240.1

IGMP(0): MRT Add/Update Vlan950 for (*,239.194.240.1) by 0

Shouldn't the controller at all times stay joined in its mobiility group ?

  • Getting Started with Wireless
1 REPLY
Bronze

Re: mobility groups with multicast - 7.4.100.60

ok, some more debugging.

I loaded up 7.4.100.60 on a 5500 controller and got the same result.

NOTE: my global multicast settings are:

Controller->General: AP Multicast Mode: UNICAST

Controller->Multicast->Global Multicast is NOT enabled

Controller->Mobility->Multicast Messaging: enabled and group is 239.194.240.3

With this config, the IGMP entry is not retained, and i see on the controller the message (debug bcast all):

>>processEthernetIGMPpacket Received IGMP Pkt from DS when either igmp snooping or global multicast is disabled.

So, i then enabled Global Multicast  (Controller->Multicast->Global Multicast to enable), and then the  IGMP entry is refreshed:

bcastReceiveTask: Sep 05 13:11:17.734:  IGMP packet received over vlanid = 102 from DS side

*bcastReceiveTask: Sep 05 13:11:17.734:  received an IGMP query for multicast vlan = 102 address 0.0.0.0 intfnum = 3

*bcastReceiveTask: Sep 05 13:11:17.734: IGMP report scheduled for grp=0xefc2f003, vlan=102, intf=3, slot=70, maxRespTime=100

>>sh ip igmp membership 239.194.240.3                                     

004586: Sep  5 15:11:50.710 CEST: IGMP(0): Send v2 general Query on Vlan101

Flags: A  - aggregate, T - tracked

       L  - Local, S - static, V - virtual, R - Reported through v3

       I - v3lite, U - Urd, M - SSM (S,G) channel

       1,2,3 - The version of IGMP, the group is in

Channel/Group-Flags:

       / - Filtering entry (Exclude mode (S,G), Include mode (G))

Reporter:

       - last reporter if group is not explicitly tracked

       /      - reporter in include mode, reporter in exclude

Channel/Group                  Reporter        Uptime   Exp.  Flags  Interface

*,239.194.240.3                10.102.180.218  00:38:51 02:28 2A     Vl102

Now, on the 5500 controller i can enable global multicast, while AP multicast mode is in UNICAST.

However, on the 8500 controller, running the same firmware (7.4.100.60), when i try to enable "Global Multicast", i get:

"Multicast-Unicast mode does not support IGMP/MLD snooping.  Config mode to multicast-multicast first". I did not get this message on  the 5500.

So when switching to Multicast->Multicast mode, and  then enabled "Global Multicast", then it works.

This means that in order to have mobility messaging working on 8500 in multicast, you MUST put the AP Multicast Mode to Multicast AND you must enabled "Global Multicast", otherwise it won't work.

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