Ermm Jumbo frames XP or Vista same result

[The PIT]

All network cards on my 1gig network support jumbo frames as does the unmanaged switch.

layout router > switch > three pc's


So to check whether it's working I decided to ping one pc on the network

ping 192.168.1.2 -l 1474 -f

This came back that packet needed to be fragmented but the df flag was set which tells me jumbo frames aren't going through.

So I did a direct connection between two pc's double checked that frames were enabled and got the same answer.

Tried my NAS and that came back with the same answer.

So what am I missing ??? Googling doesn't provide any answers really.

[Evildead666]

Are they all the same brand name ?
I've found that there isn't really a Jumbo frame standard, and they all use differing size of what they call 'jumbo' frames.

You do have everything jumbo frame capable, which is one of the pre-requisites.

[The PIT]

Well I connected two cards of the same type together and got the same result. Missing something somewhere.

[Evildead666]

Hmmm.
That should have worked....

Have you tried with both types of network cable, crossed and straight ?
I would expect it to work in both cases, but you never know, and its good to try all the possibilities, if even to eliminate them...

The fastest network I ever had was a two card Netgear GA-302T and Netgear 5 port Gigabit switch, the metal ones, not the plastic home ones.
It was as fast as using my internal HDD's....
All three of the GA-302T's died after a while, and the new models used Realtek chips instead of Atheos (i think)...
Have gone all Intel (where possible) since then.....

edit : What make and model are they ? Realtek chips ?

[The PIT]

Well the ones I connect together were both marvel 88e8056 onboard adaptors.

Prior to that it was an Intel pro 1000 pt to the marvel.

The other equipment was a Buffalo Link Station which supports jumbo frames.

[Helevitia]

Did you enable jumbo frames in the NIC card properties? Also, I've never heard of an unmanaged switch that supports jumbo frames.

[The PIT]

Did you enable jumbo frames in the NIC card properties? Also, I've never heard of an unmanaged switch that supports jumbo frames.

Yup and the netgear does according specs and other reviewers testing. Besides I took it out of the equation by connecting the machines together.

[The PIT]

Any ideas???