Two 3750G Switch via Fiber, MTU trouble, HELP!

[bc4switch]

Hello, I have  switch1: 3750G 24TS-1U and switch2: 3750G 24TS-S.

Port 25 on switch1 is connected to Port 26 on switch2, both ports are set to be trunk ports

.

I have two windows 2008 servers: server1 and server2. Server1 is connected to port 18 on switch1 with IP 10.10.6.11,

server2 is connected to port 23 on switch2 with IP 10.10.6.12.

MTU on both switches are set to be 1500, MTU on the two windows 2008 servers are also 1500.

OK, now the problem:

If I logon to server1(10.10.6.11), and issue the following command:

              ping -f -l 500 10.10.6.12, return is OK

              ping -f -l 600 10.10.6.12, timeout!

I get timeout on the second command with packet size 600, why? Can anyone please help to explain what is my problem here?

Thanks.

[vmiller]

Assuming microsoft ping -l is the send buffer size which may (or may not) be equal to the MTU. -f is the do not frag flag.

take a look at this document, under the extended commands.

http://www.cisco.com/en/US/partner/tech/tk365/technologies_tech_note09186a0080093f22.shtml

[bc4switch]

I cannot open the link. Got the following error:

Forbidden File or Application

[Ryan Gadwood]

Bin Chen,

Try this one instead...

http://www.cisco.com/en/US/tech/tk365/technologies_tech_note09186a0080093f22.shtml

[bc4switch]

Thanks. But my problem is with switches not router. Can you please provide some insights as what might be wrong with my configurations?

Thanks.

[vmiller]

Ping is not specific to routers only.

It may not have anything to do with your configurations. but you could post them here after removing all sensitve data.