EC or seperate links?

cisconoobie · ‎10-19-2007

Connecting Distribution layer into the Core. If I have Gb links and I wanted to connect to the core with 4 gb of bandwidth.

Should I create a 4 link Layer 3 etherchannel and use 1 IP or use 4 seperate links and put ip addresses on them, load-balancing them with ospf?

What would you do?

amdil · ‎10-22-2007

I assume you've got 2 points of stick between distribution and core layer.

In my opinion EC is better option. It's easy to configure and faster solution.

BR.

Amdil

bvsnarayana03 · ‎10-22-2007

Its ideal to create an Etherchannel in such cases of achieving high speed backbone on switches.

Let OSPF take decisions on routing traffic.

ilya.varlashkin · ‎10-22-2007

If you connect two switches, then etherchannel is the only way to keep all links utilised, else STP will put all but one link into blocking state.

On the other hand, connecting two routers or a router to a switch both etherchannel and routing-based load balancing will perform virtually equal since both can use SRC-DST IP addresses pairs to decide which link to use. New CEF load balancing algorithm can in some situations be better as, according to Cisco, it's more robust against global synchronisation where.

So, if you connect switches - use etherchannel, if you connect routers - use CEF load-balancing.