Atlas 550 Default Gateway Conflict

[Anonymous]

There are 3 places to set this:

1) System Config/Ethernet Port: Default Gateway;

2) Router/IP/Static Routes: Gateway; and

3) Router/IP/Global: Default Gateway.

Which is the "correct" place?

This seems to matter because, after a reboot, the route table gets (incorrectly) populated with the *wrong* interface name for the default (0.0.0.0 0.0.0.0) route and then becomes unreachable from all but the local LAN. Is there a permanent way to fix this?

Thank you sincerely.

[Anonymous]

First, ensure the FW is up to date and the ATLAS is running C0904 FW.

The Default Gateway should be configured under the SYSTEM CONFIG in the ETHERNET PORT, which should also populate the "Router/IP/Global: Default Gateway" setting.

Under "Router/IP/Static Routes" there should be no "all zeros" route listed, as this can cause a default gateway conflict if it does not match what is configured under the Ethernet Port/Global gateway.

If you are using the ATLAS as an IP router, keep in mind that while the ATLAS has routing capabilities it is not a ROUTER, and you will get much better performance from a dedicated router.

Hope this helps,

Patrick

[Anonymous]

Patrick,

Thank you for your kind answer.

But I think we've got a bug here. It doesn't seem to matter where I set the Default Gateway (in 1, 2, or all 3 places).

After a reboot the routing table goes FROM:

     IP Address        Netmask         Gateway     Interface
     ----------        -------         -------     ---------
1  0.0.0.0         0.0.0.0         10.0.0.1          EN0 IP
2  10.0.0.0        255.255.255.0   10.0.0.55         EN0 IP
3  10.0.0.55       255.255.255.255 10.0.0.55         Local
4  10.1.4.0        255.255.255.252 10.1.4.1          Link 1
5  10.1.4.1        255.255.255.255 10.1.4.1          Local
6  127.0.0.1       255.255.255.255 127.0.0.1         Local
7  224.0.0.5       255.255.255.255 224.0.0.5         Local
8  224.0.0.6       255.255.255.255 224.0.0.6         Local
9  224.0.0.9       255.255.255.255 224.0.0.9         Local
10 255.255.255.255 255.255.255.255 10.0.0.55         Local

TO:

     IP Address        Netmask         Gateway     Interface
     ----------        -------         -------     ---------
1  0.0.0.0         0.0.0.0         10.0.0.1          Link 1
2  10.0.0.0        255.255.255.0   10.0.0.55         EN0 IP
3  10.0.0.55       255.255.255.255 10.0.0.55         Local
4  10.1.4.0        255.255.255.252 10.1.4.1          Link 1
5  10.1.4.1        255.255.255.255 10.1.4.1          Local
6  127.0.0.1       255.255.255.255 127.0.0.1         Local
7  224.0.0.5       255.255.255.255 224.0.0.5         Local
8  224.0.0.6       255.255.255.255 224.0.0.6         Local
9  224.0.0.9       255.255.255.255 224.0.0.9         Local
10 255.255.255.255 255.255.255.255 10.0.0.55         Local

As you can see, the interface for 10.0.0.1 has been corrupted from "EN0 IP" (correct) to "Link 1" (wrong). Now the 550 is unreachable from anything but a local LAN.

The router should know better than this! What gives? Do you think there's a work-around?

From the System Info screen:
Firmware Revision        ATLAS 550  Rev. C.09.04 08/24/04 11:06:
Boot ROM Rev             C.01 06/26/03

Thank you again.

[Anonymous]

Patrick,

P.S. As I should have mentioned above, there are NO entries in the static routes table (not that it matters; I've tried this every which way, and it still screws up); and this Atlas 550 is being used primarily as a telephone circuit switch. The only IP routing it is called upon to do is to provide telnet access to a distant TA850(3rdGenRCU) over the unused DS0s of a T1.

Thank you.

[Anonymous]

Thank you for the additional information. This is not "typical" behavior for the ATLAS, but I believe I have seen this before. You can try factory defaulting the ATLAS (https://supportforums.adtran.com/docs/DOC-4454), and then rebuilding the configuration.

My other suggestion may be a bit odd, but can you change the address range for the PPP link between the ATLAS and the TA850 to something like a 192.168.X.X address (an address that starts with something besides 10)?

[Anonymous]

Patrick,

Thank you for the off-the-wall ideas; they are exactly what I was looking for. Unfortunately I don't have time to now redo the whole 550, and it's a long trip to the TA850 if I screw up in changing its IP address from here. So it will probably be a while before I get around to trying these ideas. Please let me know if you think of anything else. Is this just a "quirk" of the 550?

Thank you.

[Anonymous]

Yes, this is basically a quirk of the ATLAS 550. As I mentioned before, it doesn't happen all the time, but I have seen it before.