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New Member

Aux to Aux connections

Is it possible to connect two routers with a single cable directly via there Aux ports? And if so, how do you configure them to talk to each other.

I was thinking along the lines of testing purposes or for just making another connection in a lab enviroment when you run out of other ports.

Hopefully not a dumb question and aimed at the right discussion group.

New Member

Re: Aux to Aux connections

Not a dumb question at all. Here is the link:

New Member

Re: Aux to Aux connections



New Member

Re: Aux to Aux connections

I need help about aux-to-axu connection..

Actually I'm preparing for ccie lab...

Thing I got stuck is that I have no isdn stuff.

So I'm going to use aux-to-aux as a subsitute..

make it backup line when primary line down.

Problem is when I configured aux-to-aux as web site

illustrated...The connection is always up...

It should be up(spoofing) or something and should be

up when primary line got simulate isdn..

Any advice will be appreciated...

New Member

Re: Aux to Aux connections

Here is a better link for what you are trying to do:

I have never used it myself but it does specifically mention using an aux port as DDR backup. I think you might need a pair of modems between your aux ports in this type of setup since they use chat scripts to dial. Unless you can figure out a way to set the aux as a dtr dialer?

Good luck.

New Member

Re: Aux to Aux connections

Thanks for your reply..

One thing I didn't mention is that I used rolled-over

cable, no modems between aux port...

I think that makes the backup line always up...bad...

I myself am not familiar with dialer-up access...

what does the dtr dialer mean?

New Member

Re: Aux to Aux connections

When you set up DDR, you will need to tell the interface that does the dialing how to go about it's job. Often times that involves a script of AT commands. Sometimes that isn't practical. The alternative is "DTR dialer." This means that the backup interface will merely assert DTR in order to bring the circuit up. Normally, you have a device that goes and dials a number stored in a bin when DTR is asserted. Or Maybe you could connect DTR on one side of a back-to-back connection to CD on the other side. Something along that line.

New Member

Re: Aux to Aux connections

I have configured two routers to do this but I forget how I did it. I do remember that I did a serch on the CCO site for "Back-to-Back aux"