Connecting to both cable modems (NAT?)

Hi there,

this is a totally silly question, I know, but I can’t get along with it.

We have two servers (192.168.0.10 and 192.168.0.11) in the network both running with ipfire. Behind each there is a cable-modem (RED) with the ip-adresses 192.168.178.1 and 192.168.178.2
Both ipfire-servers are reachable from my client, I can administrate both very good, so no problem. But I simply can only administrate one of the cable modems 192.168.178.1.

A switch connects both IPFire-Servers to the whole network to create a redundancy connection to the internet for all clients, if one of the connection is not available.

The first router for the clients is always the 192.168.0.10, the fallback the 192.168.0.11.

I am simply to silly to get it to work, that I can administrate the second cable modem.

Any ideas?

OK OK now we know that you are silly. So that is the problem!

So this is totally normal because the default route for non-local traffic of the switch is ipfire1. Only if ipfire1 and/or (don’t know the config of your switch) the modem and/or the target/internet is not available, the default route will be changed to ipfire2.

As long as you don’t know the configuration/behavior of your switch you will not be able to understand the system.

Ask your administrator.

You can manually config the gateway of the computer you want to access to ipfire2/modem with the ip of ipfire2. So all non-local requests will be send to ipfire2. Since ipfire2 knows his own ip on red you will be able to access modem2.

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laughing:> Ask your administrator.

hmpf… :blush: I asked myself already, but I am mean to me and I won’t tell myself the solution… :laughing:

You can manually config the gateway of the computer you want to access to ipfire2/modem with the ip of ipfire2. So all non-local requests will be send to ipfire2. Since ipfire2 knows his own ip on red you will be able to access modem2.

I already suspected that. But I was in hope, that there might be a better solution. More simple, than reconfiguring the network of the client.

Anyway: Thanks for your help!

But the picture shows a different constellation. Your Clients are only “Modem im Steiger”. Da denke ich nur an Bergbau.

Your 2 DSLAM handle the “clients” and every DSLAM is connected to a switch that is connected to a Fujitsu server (ipfire). So both DSLAM must handle their failover.

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Hi, thanks for your reply.

well, I configured the clients (behind the “Modem im Steiger”. the WCs on the floors are called “Steiger” here.) to use the failover router (server2), if it can’t get an answer from the server1. The entry is the second gateway. This functions well.

But I think we get offtopic now?

Greetz Denise

The only thing I wanted to say is that not the switches handle the failover, but the DSLAMs. Gude!

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Mh, not really. These DSLAMS are Zyxel ones, but they are not able to handle a failover - bad. When I asked ZyXEL Comm for informations, this was one thing I did not ask for. And my plan 10 years ago looked diffrent to the needs of today. The modems are distributed to both DSLAMS in such a way that the entire network would only fail partiell. This way, one department could continue to work and the neighboring department would have no Internet. But they could use the working computers of the neighboring department as well. Today, the needs have changed completely. And we have to change it of course.

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