[c-nsp] Cisco 7600 multicast traffic - strange behavior

[Artyom Viklenko]

Hi, List!

I need some help solving strange problem with multicast
traffic forwarding.

At the main POP we have 7600 router which connected with
two TenGig interfaces to the main backbone ring in the
city. Port Gi3/2 connected to 3560G switch acting as a
multicast router for IPTV. Several PIM neigbors connected
to it via vlans passing through 7600 router. Yesterday
one customer bring up his PIM router and join
all multicast groups (total of 90 in range of 239.0.0.1
through 239.0.0.90). This lead to 400Mbit/s traffic from
3560G switch through 7600 router in the customer's vlan.

Backbone ring include other 7600 router and several 3750E
switches. This ring is L2 with MSTP.

Later I found that main 7600 router sends all this multicast
traffic to all trunk ports containing customer's vlan including
two TenGig backbone ports and two other GigE ports.

7600 router runs 12.2(33)SRD4 Adv. IP Services.

Mod Ports Card Type                              Model
--- ---- -------------------------------------- ------------------
   1   48  CEF720 48 port 1000mb SFP              WS-X6748-SFP
   2    8  CEF720 8 port 10GE with DFC            WS-X6708-10GE
   3   48  CEF720 48 port 10/100/1000mb Ethernet  WS-X6748-GE-TX
   5    2  Route Switch Processor 720 (Active)    RSP720-3CXL-GE

Also, ip multicast routing switched on and MVPN vrf configured
on it - have plans to dismiss 3560G as multicast router.

I try to find any glue in Cisco docs and google - no luck.

Is it expected behavior or a bug, or misconfig of something.
Why router sends multicast traffic to all ports which members
of customer vlan? There is no igmp joins nor PIM traffic through
some of these ports.

Please, point me in right direction.
Thanks!

-- 
            Sincerely yours,
                             Artyom Viklenko.
-------------------------------------------------------
artem at aws-net.org.ua | http://www.aws-net.org.ua/~artem
artem at viklenko.net   | ================================
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