LAN, SDSL and ADSL routing problems

[Sleurhutje]

Hi,

I have a network with several servers, of which one is a Win2K Terminal
Server. This TS can be accessed both over the LAN and from the Internet.

The Internet connection was made using a Cable Modem connection from the
local cable company and all works fine. Since a few weeks we have a SDSL
connection that's much faster than the cable link.

Easy thought was connecting the TS to both the cable connection and SDSL
connection where the cable connection would operate as a backup link if the
SDSL fails (not a bad idea because they use totally different media for data
transfer).

The configuration with the cable connection was:
Server IP LAN: 192.168.0.246/24
Server IP cable modem: 172.17.0.246/24
Router cable modem: 172.17.0.1/24
No gateways configured
RRAS static routes
172.17.0.0 255.255.255.0 192.168.0.246 1
192.168.0.0 255.255.255.0 172.17.0.246 1
0.0.0.0 0.0.0.0 172.17.0.1 1

So I added another IP to the NIC, 172.17.2.246/24, and changed the RRAS
static routes to:
172.17.0.0 255.255.255.0 192.168.0.246 1
172.17.0.0 255.255.255.0 172.17.2.246 1
192.168.0.0 255.255.255.0 172.17.0.246 1
192.168.0.0 255.255.255.0 172.17.2.246 1
0.0.0.0 0.0.0.0 172.17.0.1 1
0.0.0.0 0.0.0.0 172.17.2.1 1
Where 172.17.2.1/24 is the address of the SDSL router interface.

If I remove one of the two 0.0.0.0 routes all works fine for just one of the
internet connections. But I discovered this didn't work at all when both are
added.


So who can provide me the correct routing configuration to get all things
working??? Any help will be very appreciated.


Jeroen

 

[Jetro]

I would uninstall RRAS from TS server at all and add second hardware router
to this network.

 

[Sleurhutje]

There are two routers already. One serves teh cable connection, the other
the SDSL connection. But managemennt wanted the two networks separated in
two different ranges. But remote workers should be able to use both
connections.

Even if I use the two routers on the same network/subnet I have the problem
that only one is the default gateway. I.e. cable router 172.17.1.246 and
SDSL router 172.17.1.245.

With or without RRAS, the primairy or first gateway is always used,
regardless of th einterface metrics. I tried without RRAS, set the SDSL
gateway to metric 1. It doesn't matter what will be the second gateway and
what metric, if the SDSL router or link is down, no packets arrive to the
cable router and incoming packets are replied using the SDSL link.

This is a pain in the <you know what>...


Jeroen

 

[Jetro]

Old article (July 2k2)
http://msdn.microsoft.com/library/default.asp?url=/library/en-us/dnw2kmag00/html/Redundant2.asp
Build Redundant IP Routing.
If you need BGP-capable routers it could be Cisco line.