Re: MTU problem between 10/100 & Gigabit cards
Gary Smith <[email protected]> Tue, 03 Jul 2007 17:28:01 +0100
| Newsgroups | gmane.linux.drivers.vlan |
|---|---|
| Organization | Phoenix Broadband Ltd |
| Message-ID | <[email protected]> |
--===============0485532228== Content-Type: text/html; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit <!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"> <html> <head> <meta content="text/html;charset=ISO-8859-1" http-equiv="Content-Type"> <title></title> </head> <body bgcolor="#ffffff" text="#000000"> Is their a list of drivers with their corresponding MTU size required.<br> <br> Some of the old 10/110 as well as gig cards.<br> <br> Thanks<br> <br> <br> <pre class="moz-signature" cols="72">Gary </pre> <br> <br> Ard van Breemen wrote: <blockquote cite="[email protected]" type="cite"> <pre wrap="">Hi, On Fri, Jun 29, 2007 at 05:19:06PM +0100, Gary Smith wrote: </pre> <blockquote type="cite"> <pre wrap="">I have been running a VLAN configured system for some years using 10/100 Sundance driver cards without a problem. I recently tried on a HP proliant server using gigabit cards and found a problem related to the MTU size for the interface I an using. The 10/100 cards seem to need a MTU of 1504 bytes, but this size does not work with the e1000 gig cards, or the US robotics, Dlink DGE, broadcom etc. I have to move the MTU down to 1500 to make fragmentation work and allow it to pass the larger packets. </pre> </blockquote> <pre wrap=""><!----> >From what I read, I guesss the vlan on sundance is software only, and need a special MTU of 1504. Most gigabit cards (not all!) already strip the vlan tag, so the driver only sees a payload of 1500 and somewhere else in the receiver buffer the vlan tag is found. </pre> <blockquote type="cite"> <pre wrap="">Is this what I should expect from the e1000, broadcom, R8169 drivers for gigabit cards? </pre> </blockquote> <pre wrap=""><!----> I've been using vlans since 2.4.14 or so, and I have never had to set the MTU size to 1504 for any of my cards. I do know however that some of the drivers need the MTU size of 1504 to keep it from discarding it as a long packet and to cope for the increased buffer size needed. _______________________________________________ Vlan mailing list <a class="moz-txt-link-abbreviated" href="mailto:[email protected]">[email protected]</a> <a class="moz-txt-link-freetext" href="http://www.candelatech.com/mailman/listinfo/vlan">http://www.candelatech.com/mailman/listinfo/vlan</a> </pre> </blockquote> </body> </html> --===============0485532228== Content-Type: text/plain; charset="us-ascii" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Content-Disposition: inline _______________________________________________ Vlan mailing list [email protected] http://www.candelatech.com/mailman/listinfo/vlan --===============0485532228==--