>
http://bugzilla.kernel.org/show_bug.cgi?id=9270
>
> Summary: sunhme requires lower MTU to handle 802.1q frames
> Product: Drivers
> Version: 2.5
> KernelVersion: 2.6.18-3
> Platform: All
> OS/Version: Linux
> Tree: Mainline
> Status: NEW
> Severity: normal
> Priority: P1
> Component: Network
> AssignedTo:
jgarzik@pobox.com
> ReportedBy:
dev-null@telus.net
>
>
> Most recent kernel where this bug did not occur: N/A
> Distribution: Debian 4.0r1 (Etch)
> Hardware Environment: Sun Netra T1 105
> Software Environment:
> Problem Description:
> sunhme requires lower MTU to handle 802.1q frames - even though the PCI
> driver supported VLAN tagging, you cannot do full MTU @ 1500 because the
> driver doesn't set the card to transfer more the extra bytes for a 802.1q
> frame at 1500 MTU.
>
> Steps to reproduce:
> modprobe 8021q
> modprobe sunhme
> ifconfig eth0 up
> vconfig set_name_type DEV_PLUS_VID_NO_PAD
> vconfig add eth0 10
> ifconfig eth0.10 192.l68.0.1 netmask 255.255.255.252 broadcast 192.168.0.3 up
> # IP pkt size = 1496, Ethernet frame size = 1514
> ping -s 1468 -c 1 -w 1 192.168.0.2
> # IP pkt size = 1500, Ethernet frame size = 1518
> ping -s 1472 -c 1 -w 1 192.168.0.2