[c-nsp] multicast NOT in HW on 7600

[Phil Mayers]

On Wed, Aug 20, 2008 at 09:04:27PM +0300, Liviu Pislaru wrote:
>hi
>
>i have a multicast problem in the following topology;
>
>TOPOLOGY:
>Msource -> R1(SVI 10) ---trunk--- (SVI 10) R2 ---routed--- R3 ......Rn ...
>Receiver
>
>- R1(7613), R2(7609), R(7613) / IOS SRA3 / WS-SUP720-3BXL
>- 10G link between them in WS-X6704-10GE linecards with DFC
>- trunk between R1 and R2, link routed between R2 and R3
>- SVI 10 has "ip pim sparse-mode" and "mpls ip" so R1 is PE router and R2,R3
>...Rn are P routers.
>- routed links between P routers has "ip pim sparse-mode" and "mpls ip"
>- Msource (multicast source) interface from R1(routed) is configured in vrf
>XXX
>- BGP address-family ipv4 mdt configured on R1 (and all other PE)
>
>PROBLEM:
>all multicast traffic goes to RP on R2 (is software processed), CPU load
>increase, etc ...

Something is configured wrong somewhere. Can you supply the output of:

sh run | inc ^ip (pim|multi)
sh run int Vlan10
sh ip pim int
sh ip pim nei
sh ip rpf SOURCEIP

...on both R1 and R2?

It sounds to me as if R2 isn't correctly configured as an RP, or isn't 
able to send the PIM joins which would push things down into hardware - 
the initial packets to the RP are always in software, so that's normal, 
but it's not normal for the traffic to be continually CPU-punted.