Hi,
My question is 1) can I make etherchannel / port channel for two interface ; will I work??
Yes, you can. As long as the 2 ports have the same speed and duplex you should be fine.
2) does fail over will work within etherchannel; how switch will come to know port is down; will physical l2 interface goes down if link gets down in between specially mux is in between them??
If the mux goes down, it will cause the interface on the switch to go down as well. When that happens, the switch will forward all packets using the other port.
3) if I don't go for etherchannel, then spanning tree will block one port.. but if link is down in between switch port will not receive bpdu so failover can be done. is it?? or port need to get down physically ?
For this type of scenario is it a good idea to use a Portchannel. This way both links can forward and load share traffic, if not STP will block one of the ports at all times.
BTW, if the switches are far from each other you would have to use SM fiber with SM optics.
HTH
