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New Member

Leased Line Bundling

Is it possible that you can bundle 2 Leased Line as 1 Line on serial link?

We have a customer who has two 128K Leased Line in serial interface S0 and

S1 respectively, he wants to bundle the link into 1 256K link like in dialup

/ ISDN you do the multilink, what are the possibilities and configurations

require to do the task in serial interface, he is using HDLC encapsulation

and so we are.

Another thing is, is it possible you can use 1 serial connection for SMTP

traffic and 1 serial for other internet traffic? if yes can you provide the

related config example.

Pls reply as soon as possible.

New Member

Re: Leased Line Bundling

The answer to your first paragraph is YES you can bundle the two serial lines, you will however need to use PPP encap with multilink enabled. Cisco site has alot of info on this. If your cust just wants the second link to come up ONLY when load excees set amount you can config second serial as a backup load interface.

As for the second question: Why bundle and then seperate traffic?

You can seperate traffic by using route maps/policy routing.

Hope this helps!

New Member

Re: Leased Line Bundling

If If you have one router on one side, and one router on other side, the you can make it this way:

1) on both routers create an Loopback interface

2) assign them /30 addresses

3) on every interface (for ex. serial0 and serial1) put the `ip unnumbered loopback X` command

4) create all necessary routes

this should work.

For the second question, route maps will help you:

Cisco Employee

Re: Leased Line Bundling

The best way to multilink two serial link is using encapsulation PPP. PPP encapsulation with multilink will give you added option of link fragmentation with aggregated speed.

Here is the url which discuss multilinking two serial links togather with sample config and troubleshooting.

New Member

Re: Leased Line Bundling

Thank you all for your fruitful replies!

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