Multicast / CGMP and Ghost server

[mgoddard]

Hi,

I'm in need of advice on using ghost server to deploy images across our VLANs.

I've enabled Pim sparse mode and of course ip multicast on our core switches (CAT2948) for the 2 VLANs currently being used for ghosting.

This part works fine but the CAT3500XL access layer switches are flooding the multicast to all 24 ports and taking a huge performance hit.

CGMP is enabled by default but beyond that their is no further configuration and IGMP options other than the basic CGMP ones are not supported.

Any ideas on where I'm going wrong? Short of throttling back the ghost server I'm at a loss.

Thanks

Matt

[Bobby Thekkekandam]

do you have "ip cgmp" configured on your multicast router?

i.e.

ip multicast-routing

interface Vlan2

ip pim sparse-mode

ip cgmp

some documentation on implementing CGMP. unlike igmp snooping, constraining multicast on a switch using cgmp requires enabling cgmp on the multicast router as well.

http://www.cisco.com/warp/customer/473/22.html#cgmp

HTH,

Bobby

[mgoddard]

Hi Bobby,

I forgot about that end of things!

I've just tried to enable cgmp against the BVI group but I get the error message 'CGMP not supported on non-802 media' I assume that I need to enable it against the fastethernet interface that the VLAN operates out of instead.

I'll try it next week and confirm.

Thanks for your help.

Matt

[mgoddard]

I've enabled cgmp on each fastethernet port relating to the VLANs to be used for multicast and it works a treat, the multicast traffic now only hits the switches it should.

Thanks.