* David Christensen <[EMAIL PROTECTED]> [070907 10:48] wrote: > > > It could certainly be argued by some that Cisco is not standards > > > compliant in this case for sending an oversized Ethernet frame > > > and expecting everyone to accept it. Hardware has limitations > > > and assuming that all Ethernet controllers can support frames > > > greater than 1522 bytes is not reasonable. Fortunately there is > > > a suitable workaround which is setting a larger MTU for the > > > interface. What size do you use? How did you arrive at that > > > value? > > > > I use 1550 to make it work in the test harness. > > > > The trouble is that if I set the mtu to 1550, and the machine > > talks to another > > such machine with it's mtu also set to 1550 then they > > negotiate a maximum sized > > packet based on 1550, and the problem hits me again. This is > > a web proxy > > and that problem occurs when there are two layers of proxy > > and one proxy talks to > > another. I really just need it to to silently accept a packet some > > 32 bytes or so larger than the stated MTU. > > > > I see no reason for the driver to not do what the em driver > > does and allow > > itself to receive any packet up to the MCLBYTES size. > > > > We only hit this problem recently because the data interfaces on our > > devices are usually em NICs and we only just recently started > > allowing the > > users to use the built in (on DELL 2950) bce interfaces for > > this purpose. > > > > I'm not completely opposed to making such a change, but I don't want > to make a default change in the driver's behavior that other people > may be depending upon (whether they are aware of it or not). A > tunable driver value could be the answer but I'm not entirely sure > how it would fare in the hardware at the high end of MTU values such > as 9000.
Dave: Internet ettiquette demands being gracious in what you accept. The default policy of FreeBSD is to accept such packets. This is a really weird bug to track down. Other drivers support it. This isn't worth making a stand over, unless you're trying to hold users of YOUR driver hostage. -- - Alfred Perlstein _______________________________________________ freebsd-net@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-net To unsubscribe, send any mail to "[EMAIL PROTECTED]"
