Add a default route on swichport

IM-Design · ‎02-02-2009

Greetings,

I have a network with a single 3750G switch and an 1841 router. Both WAN ports on the 1841 router are in use and are load-balanced.

I would like to add another WAN link to the 3750G switch and direct some of the internet-bound traffic to this link, rather than all traffic exclusively going to one of the WAN ports on the 1841.

What can I do to realize this?

TIA

celiocarreto · ‎02-02-2009

Hi,

you can use for example 2 static routes:

ip route 0.0.0.0 128.0.0.0 1841-IP

ip route 127.0.0.0 128.0.0.0 other-GW-IP

and for Backup:

ip route 0.0.0.0 128.0.0.0 other-GW-IP 254

ip route 127.0.0.0 128.0.0.0 1841-IP 254

But you will not achieve a real 50/50 split with this solution!

Regards, Celio

paolo bevilacqua · ‎02-02-2009

Which traffic you want to send there? As long you can identify, you can send it. Eg certain VLANS, certain popular destinations, etc. However it may be better to confine all routing decisions to the router. This is done having 1841 being GW for all clients, and seeing the device attached to 3750 via a specific VLAN.

In a more sophisticated configuration you can also make the 3750 be a secondary router via HSRP or GLBP in case 1841 dies.

On this theme you can also experiment with the load sharing feature of GLBP keeping the 3750 a layer 3 as well the 1841. But, I haven't tried that ever.