I have got two 6509 connected back to back via port channel( PORT CHANNEL 1). They operate on HSRP among them with multiple vlans and sharing the active router among them. All is fine until I connect another port channel that is connecting the other building to these 6509( say port channel 4). Now if i do a show mac-add-table address command on both the 6509, i can see that the HSRP IP address, not the floating one but individual one is know know via port channel 4 rather than port channel 1 as it used to be. Because of this my EIGRP running between the two 6509s fail. Could this be an STP issue, but I have configured priorities properly on the 6509 so that none of the other switches become the root. Or could it be some one is spoofing mac-ip on the building that I am trying to connect to the 6509. Please help with this issue. Hope i have made the issue clear.
sorry for the basic question but sometimes this happened.
and the C3750 is never STP root for any vlan ?
Any native vlan mismatch on trunk?
Hope to help