Kindly;examine the attachment:
i want etherchannel to load balance across 4 links..EXPERT'S What is ur Suggestion here L3 OR L2 Link between Site 1 & site 2;if so why ?
How are you ?? Here is my suggestion :
It really depends on your requirements to select a L2 or L3 trunk... If you want VLAN propogation across the sites, ie extending the LAN on site 1 to site 2, with both the sites having the same VLANs, you need to go for a L2 trunk solution... In case you have a L2 trunk, you can configure etherchannels and bundle the trunks to a logical BIG pipe.. you can use the load balancing feature in etherchannel to distribute the load based on SRC-DEST MAC or SRC-DEST IP... you just need to configure a simple command for this...
On the other hand.. if you want isolated LANs on site 1 and site 2, you can configure Layer 3 trunks between the sites.. In this model, the VLAN information on site 1 will not be propogated to site 2 and the only way they could reach each other is through L3 routing on the core.. If L3 trunks are configured, you dont need to configure etherchannels.. You can do load balancing using simple static routes:
ip route 10.10.10.0 255.255.255.0 ge0/1
ip route 10.10.10.0 255.255.255.0 ge0/2
ip route 10.10.10.0 255.255.255.0 ge0/3
or do it with any routing protocol if needed...
I would suggest the second method, of configuring L3 between the sites, because the broadcast domains will be limited to the local site and will stop unnecessary broadcasts over the WAN.. this is the best way of doing it...
Hope this helps.. all the best.. rate replies if found useful..