Ethereal-users: Re: [Ethereal-users] Jumbo Frames

Note: This archive is from the project's previous web site, ethereal.com. This list is no longer active.

From: "ESQuicksall_Misc" <ESQuicksall_Misc@xxxxxxxxxxx>
Date: Sat, 25 Mar 2006 15:33:28 -0500
I'm not sure where you got that from. Here it is again: on the DELL D810 side (where I'm running Ethereal) I have a Broadcom NetXtreme 57xx Gigabit Controller (built into the D810). The NetXtreme does not have an option for me to select jumbo frames. The other side has a TRENDNet TEG-PCITXR 32-bit 10/100/1000Mb PCMCIA card. The TEG has an option for jumbo frames which I have enabled. Ethereal will trace with the jumbo frames disabled but not with them enabled.

Since you say Ethereal does not care if they are jumbo frames or not, then does anyone know if the DELL D810 with NetXtreme along with Winpcap have a problem capturing jumbo frames?

Eddy


----- Original Message ----- From: "Guy Harris" <gharris@xxxxxxxxx>
To: "Ethereal user support" <ethereal-users@xxxxxxxxxxxx>
Sent: Friday, March 24, 2006 2:31 PM
Subject: Re: [Ethereal-users] Jumbo Frames


ESQuicksall_Misc wrote:
I believe the NetXtreme (Broadcom) supports jumbo frames because when I configure it at the TEG side it is faster and Ethereal does not trace anymore (if the NetXtreme didn't support it then I would expect Ethereal to continue to trace).

I.e., if Ethereal *does* see jumbo frames, it means the card Ethereal's using *doesn't* support jumbo frames, but if Ethereal *doesn't* see jumbo frames, it means the card *does* support them?

That sounds a bit backwards to me....

You'd have to ask Broadcom whether

1) they support jumbo frames

and

2) if they supply jumbo frames to NDIS in the same way that they supply regular frames to NDIS

as WinPcap attaches to network card drivers via NDIS, and Ethereal does its capturing on Windows through WinPcap, so whether Ethereal sees packets depends on:

whether the network adapter sees them;

whether its driver supplies them to WinPcap via NDIS;

whether WinPcap handles the packets supplied to it.

(I.e., this is almost certainly not an Ethereal issue, it's almost certainly a driver or WinPcap issue. Ethereal has no concept of "jumbo frames", it just knows Ethereal frames, and doesn't particularly care if they're bigger than the "proper" maximum size.

Try capturing with WinDump; if it has the same symptoms as Ethereal, it's a driver or WinPcap issue, and I'd bet on it being a driver issue.)
_______________________________________________
Ethereal-users mailing list
Ethereal-users@xxxxxxxxxxxx
http://www.ethereal.com/mailman/listinfo/ethereal-users