EtherChannel and ip dhcp snooping does not work together

[t.fiala]

Aggregation switch C3750G is connected to distribution switch C2950 via EtherChannel (two 1G ports). If I configure on any of two switches "ip dhcp snooping" feature, DHCP packets are blocked. Without EtherChannel works snooping well (the same ip dhcp snooping configuration). Any ideas, how to configure EtherChannel to work with snooping? Thanks, Tomas

[ShivamNaik08815]

does ios version 15 support dhcp snooping trust on port channels using c 2960

[t.fiala]

Hi Mizoran.

I am not sure if you configuration is supported as to EtherChannel. It is a combination of Interstack Ether Channel with stacks on both sides. I have an experience with the configuration on the left side in the attached chart. It works with the DHCP snooping enabled since the Bug CSCeg74243 was solved. Your simplified topology is on the right side (for the 1st floor only, but all floors are analogical).  I am sorry, you described it well in your text but I saw it through from the configurations only. I would recommend ask the expert or if you have time to experiment try restrict Interstack to core site only. Configure the whole channel on the distribution site in one member only.

Regards, Tomas

[ShivamNaik08815]

how do u configure dhcp snooping on a port channel coz im using packet tracer 8 with ios version 15.0.1 and it does not recognise the ip dhcp snooping trust command which command should i use for port channel dhcp snooping can u please show me how u done it