1518 may count as Baby Giant, and not as Jumbo. Some platforms that don't support Jumbo frames can still forward Baby Giants. Also this is different depending if the link is FastEthernet vs GigEthernet or TenGigEthernet. Look at the show interface output on the Catalyst switch for that port and see what it classifies the incoming packets as. Is there a reason you simply can't lower the MTU on the server? The other alternative would be to enable Baby Giant/Jumbo frame support on the layer 2 switches in the transit path. See http://goo.gl/iMZa6 as a reference.
HTH,
Brian McGahan, CCIE #8593 (R&S/SP/Security)
bmcgahan_at_INE.com
Internetwork Expert, Inc.
http://www.INE.com
-----Original Message-----
From: nobody_at_groupstudy.com [mailto:nobody_at_groupstudy.com] On Behalf Of Bernard Steven
Sent: Wednesday, June 08, 2011 10:33 AM
To: Cisco certification
Subject: JUMBO FRAMES
What will happen if a server sends a jumbo frame to the connected switch
that does not support (not configured) Jumbo frames ?
My problem is when i capture traffic from server IF (tcpdump ) , i see large
frames (1518<) , in the mean time , switch is not configured for JF and also
i don't see any retransmissions in tcpdump. (assuming switch discards the
jumbo frame). And also i dont have any visibility on the other end of the
communication. Some how , application does not work.Switch is a 4948.
Blogs and organic groups at http://www.ccie.net
Received on Wed Jun 08 2011 - 14:08:43 ART
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