Date: Wed, 05 Jul 2000 17:56:41 +0100 From: Tim Priebe <tim@polytechnic.edu.na> To: Luigi Rizzo <luigi@info.iet.unipi.it> Cc: David Gilbert <dgilbert@velocet.ca>, tim@iafrica.com.na, Kevin Oberman <oberman@es.net>, "Louis A. Mamakos" <louie@TransSys.COM>, Joerg Micheel <joerg@cs.waikato.ac.nz>, freebsd-stable@FreeBSD.ORG Subject: Re: Ethernet MTUs > 1500? Message-ID: <396368C9.C3C5A50F@polytechnic.edu.na> References: <200007051516.RAA77416@info.iet.unipi.it>
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Luigi Rizzo wrote: > > > Kevin> Louis has it exactly right. 802.3 was modified a couple of > > Kevin> years ago to allow for a maximum frame size of 1522 octets, up > > Kevin> from the original 1518. This was to allow the VLAN information > > Kevin> to fit in the frame. > > just curious, what do we do when we have multiple encapsulation ? > (i.e. is this allowed ?) > > cheers > luigi I am not sure what you mean. If you mean "VLAN encapsulation", then it is a misunderstanding. The standard Ethernet frame is not encapsulated. The Ethernet header is modified. The extra 4 Bytes are not at the begining of the frame. The frame is identical to one with prioratization, 12 of the bits indicate the VLAN, and 4 the prority. So there is only one VLAN value, and one priority value possible per frame. Tim. To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-stable" in the body of the message
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