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New Member

Load Sharing T1 Internet Traffic

Hello Pals,

Here is the situation;

Inside->PIX->Router------>2 T1----ISP

The Internet router has 2 T1 and I need to load share between them. Only static routing can be used, no routing protocols. So if I use CEF with Static Routing would it work? PIX already does the NAT :-(

It doesn't seem to work for me. All suggestions welcome.

Cheers,

Rajesh

1 ACCEPTED SOLUTION

Accepted Solutions

Re: Load Sharing T1 Internet Traffic

Rajesh,

Yes, CEF enabled with two default routes will load balance. By default its per-destination, which means for every source, destination address pair, CEF creates a hash and chooses one of the X routes you have on the table.

Verification of load balancing can be done using command,

sh ip cef 0.0.0.0

8 REPLIES
VIP Purple

Re: Load Sharing T1 Internet Traffic

Hello,

can you post what you have configured on your router ? Two default static routes in conjunction with CEF should work...

Regards,

GP

Re: Load Sharing T1 Internet Traffic

Rajesh,

You will only see outbound load balancing. Inbound load balancing, you dont have much control of, unless you run BGP.

So what makes you think that it is not working ? If you can shed more light on how you are testing this...

Sankar.

New Member

Re: Load Sharing T1 Internet Traffic

Sankar,

Outbound load balancing is what I'm trying to do here.The thing is that I'm loosing DNS I guess. My internal AD has root nodes setup but when I turn the other route on it just sits there, no resolution.

Cheers,

Rajesh

Re: Load Sharing T1 Internet Traffic

Lets figure out first if there is your second link is routing packets outbound properly or not. I would suggest to test a few things.

a. Enable one link (T1) at a time and see if you can connect to the internet from the inside. Especially test the second T1.

b. Use a PC on the outside ethernet segment between PIX and router, assign it a public address and see if you are able to resolve DNS queries with both default routes on.

Sankar.

New Member

Re: Load Sharing T1 Internet Traffic

I agree with all the comments. But unfortunately I guess, we are drifting away from the question.

What I wanted to know was, Does CEF work with 2 equal cost STATIC routes :-)

Sankar,

I'm already talking to ISP to see if they have anything wrong.

Cheers,

Rajesh

Re: Load Sharing T1 Internet Traffic

Rajesh,

Yes, CEF enabled with two default routes will load balance. By default its per-destination, which means for every source, destination address pair, CEF creates a hash and chooses one of the X routes you have on the table.

Verification of load balancing can be done using command,

sh ip cef 0.0.0.0

New Member

Re: Load Sharing T1 Internet Traffic

Yes, thatz exactly what I wanted to know. I have problems at ISP end and I'll have to fiddle with them for it.

By the way, what are you doing late in the night at Cisco.com? Go to sleep.

Cheers,

Rajesh

New Member

Re: Load Sharing T1 Internet Traffic

Enabling CEF on your router will load balance your outing traffic, but not you incoming traffic. But many ISPs that use Cisco will enable CEF on their end and that will give what you are looking for!

Hope this helps - Cire

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