Solved: 3750 static route won't go

RichardArkner · ‎11-30-2006

I've just set up a static route in my 3750 (which has been working happily for 2 years). The route looks OK but it doesn't actually work. Is there some other setting needed?

Here's what I did (first 2 quads replaced by aaa.bbb):

=== SET UP THE ROUTE ===

Router-H#configure terminal

Enter configuration commands, one per line. End with CNTL/Z.

Router-H(config)#ip route aaa.bbb.196.0 255.255.255.0 aaa.bbb.214.15

Router-H(config)#end

=== SHOW THE ROUTE ===

Router-H#show ip route static

aaa.bbb.0.0/16 is variably subnetted, 245 subnets, 9 masks

... some other static routes ...

S aaa.bbb.196.0/24 [1/0] via aaa.bbb.214.15

... some other static routes ...

S* 0.0.0.0/0 [1/0] via aaa.bbb.4.2

=== PING THE GW ===

Router-H>ping aaa.bbb.214.15

Type escape sequence to abort.

Sending 5, 100-byte ICMP Echos to aaa.bbb.214.15, timeout is 2 seconds:

!!!!!

Success rate is 100 percent (5/5), round-trip min/avg/max = 1/1/1 ms

=== TRACE TO PAST THE GW FAILS ===

Type escape sequence to abort.

Tracing the route to aaa.bbb.196.10

1 * * *

2 * * *

3 * * *

...etc

Richard Burts · ‎12-11-2006

Richard

Thanks for posting back to the forum and indicating that you had found the solution to your problem. I am glad that my suggestion that the 214.15 device was not set up for routing showed you the right direction to look.

It makes the forum more useful when people do post back indicating the solution to their problem. Then people can read about a problem and can see what the solution was. I encourage you to continue your participation in the forum.

HTH

Rick

HTH

Rick

View solution in original post

Richard Burts · ‎11-30-2006

Richard

Some additional information would help us give you helpful advice. Can you give us some information about the topology of the network? I see that the static route in question uses aaa.bbb.214.15 as the next hop and that your default route uses aaa.bbb.4.2 as its next hop. So is it true that your 3750 has multiple outbound interfaces?

Can you tell us a bit more about the next hop of aaa.bbb.214.15? What kind of device is this? Have you sent other routes through it before or is this new? Are you sure that aaa.bbb.214.15 does have a route to the destination subnet? And does aaa.bbb.214.15 have routes to the various subnets which may be source addresses on traffic that you send through it?

HTH

Rick

HTH

Rick

RichardArkner · ‎11-30-2006

Rick-

Thanks for your prompt reply!

"So is it true that your 3750 has multiple outbound interfaces?" - yes. But I'm not clear what is meant by inbound or outbound here. I'd say that aaa.bbb.4.2 is outbound (ie towards the internet) and aaa.bbb.214.15 going into my LAN.

The device at aaa.bbb.214.15 is (AFAIK) Linux on a Shuttle, acting as gateway between aaa.bbb.214.0 and aaa.bbb.196.0. It has not been used for this before; this is the first set-up. I don't actually manage it myself, so I don't know whether it is set up yet. But since it responds to ping, I'd have expected traceroute to get at least that far. I've asked the person responsible to confirm that it is routing and that there is something for it to route to.

Richard Burts · ‎12-01-2006

Richard

The additional information is helpful. From what you are telling me I believe that the device at 214.15 is not set up for routing. I believe that it responds to pings since the ping was addressed to it. But it is not responding to traceroute because the traceroute probe packet is not addressed to it and it is not routing.

HTH

Rick

HTH

Rick

glen.grant · ‎12-09-2006

You put a static route on the 3750 , did you put one on the far end pointing back to the 3750 , if not the far end doesn't know what to do with the packets . Unles there is a specific reason not to do I would always use a routing protocol on your L3 devices it certainly simplifies things and you don't have to bother putting in static routes everywhere .

On the far end add ip route aaa.bbb.214.15 255.255.255.0 aaa.bbb.196.0

RichardArkner · ‎12-11-2006

The problem was with the gateway at aaa.bbb.214.15, which was not configured. The 3750 was fine all along. I was mistaken in thinking that the gateway's routing configuration was not important because it responded to ping. One the gateway - and a target machine beyond the gateway - were set up, everything went sweetly.

Thanks for all your help!

Richard Burts · ‎12-11-2006

Richard

Thanks for posting back to the forum and indicating that you had found the solution to your problem. I am glad that my suggestion that the 214.15 device was not set up for routing showed you the right direction to look.

It makes the forum more useful when people do post back indicating the solution to their problem. Then people can read about a problem and can see what the solution was. I encourage you to continue your participation in the forum.

HTH

Rick

HTH

Rick

aravindhs · ‎12-11-2006

Rick,

That was very nice clear succinct suggestion , problem fix rather !

cheers

Arav

Wilson Samuel · ‎12-11-2006

Hi Richard,

The same sort of problem I had faced sometime back in the month of Aug, when I ordered 3560 just to find that its acting the way it should have benn!!

Then later found that, I had to enable IP Routing on a L-3 Switch, its NOT enabled by default, though the same is NOT mentioned in the Config Guide.

Glad that you sorted at the issue without much hassels.

Regards,

Wilson Samuel