Redundant Internet connection.

[Saji Thomas]

Hello Experts,

I am trying to use a redundant ISP for our internet connection at our company. We have a 6509 Layer 3 Switch and a PIX firewall.

I learned HSRP on two routers few years back and do not remeber the details now.

Can anyone help on how to do HSRP or any other way to have a redundant connection?

Also, if we decide to do it manually if one of the ISPs go down, what is the best possible way to do it?

Thanks a lot!

[John Blakley]

You can't use hsrp on a pix. It's only supported on IOS routers/switches. Do you have 2 6509s? If so, you can configure those, but you won't be able to pair the 6509 with the PIX.

HTH,
John

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[Saji Thomas]

Hi John,

Thank you very much for taking the time to read it and reply.

That was my worry all the time. To explain the setup: We have locations A,B,C,D. They all have 6509 at every location. A is the gateway for the A office. B is the gateway for B,C and D. They have the same ISP and they all are connected via T1 ring.

Is there a way I can configure it so that if A fails, all the traffic passes through B. I guess its complicated because HSRP has to configured at every location i.e. ABCD. That being said, can we pair a 6509 with a IOS router at every location? Or do we have to buy another 6509 at every location because we already have one there.

If not, then what would be the best possible way to manually do it? Change the routing? Or do you have any other suggestions?

Thanks!

Saji

[John Blakley]

Can you post a diagram? What routing protocols do you use now?

HTH,
John

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[Lee Cobley]

You could do this using EEM script to change the routing on a failure.

[Saji Thomas]

Hello All, 

Ended  up creating a route on the 6509 with a lower value and  hopefully it works.

Thank  you all!!!

[Saji Thomas]

Hi John,

We are using EIGRP and I will post the diagram soon.

Hi Lee,

I have never used EEM. Can you give a link that has details of its configuration?

Thanks!

Saji

[Richard Burts · Accepted solution]

Saji

If I am correct in understanding your explanation the sites are connected in a ring using T1. HSRP works on Ethernet interfaces and does not work on serial T1 interfaces. Also if a site has a single 6509 it would not be able to run HSRP on its Ethernet unless you provision a second 6509 at the site. So it seems to me that HSRP is not a viable solution for you. But it does sound like that there should be a possible solution using your routing protocol. Using EIGRP it should be possible for site A to have a default route pointing to its ISP and to learn a less attractive default route via EIGRP from B that it could use if its primary default route stops working. We would need to have more information about your environment to be able to suggest how that would work.

HTH

Rick

[Saji Thomas]

Hi Richard, sorry for the delay. Something urgent came up.

The basic understanding and the diagram of the circuit is below. A,B,C,D and E are connected via T1. A has its own gateway and all other go through D. All can access the servers and the resources. If D is down, B,C,D and E have no internet. If A is down, only A has no internet.

We plan to have another ISP at every location (ABCDE). So, if A is down, internet should go from redundant A ISP. If D is down, then BCDE should go out using their own redundant ISP. I am looking into the config and will let you know more details.

[Saji Thomas]

Hi John,

The picture is attached and we used EIGRP and EIGRP external.

Thanks for looking into it.

Regards,

Saji