port-i386/38871: vlans don't work on bge interface

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>Number:         38871
>Category:       port-i386
>Synopsis:       vlans don't work on bge interface
>Confidential:   no
>Severity:       serious
>Priority:       medium
>Responsible:    port-i386-maintainer
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Thu Jun 05 15:10:00 +0000 2008
>Originator:     Alan Barrett
>Release:        NetBSD 4.99.63
>Organization:
Not much
>Description:
        802.1q vlans do not work properly on bge inetrfaces on NetBSD/i386

>How-To-Repeat:
        Configure multiple vlans on a suitable ethernet switch.
        Have some of the switch ports configured to use 802.1q tags.

        Connect the "bge0" interface on a NetBSD/i386 host to a
        switch port that is configured as a trunk containing multiple
        vlans with 802.1q tags.

        Cause non-NetBSD hosts to send broadcast packets inside the
        vlans.

        Run "tcpdump -i bge0 -lenvv" on the NetBSD host.  Observe that
        the packets that should have vlan tags do not have vlan tags.

        Run "tcpdump -i bge0 -lenvv vlan" on the NetBSD host.  Observe that
        no packets pass the filter.

        Configure a vlan interface on the NetBSD host, via "ifconfig vlan42
        create; ifconfig vlan42 vlan 42 vlanif bge0".  Run "tcpdump -i vlan42
        -lenvv".  Observe that no packets apear.

>Fix:
        Unknown.

        One theory is that the hardware is removing the VLAN tag headers
        before the OS can see them.  It is possible that the hardware
        can be configured not to do this.

>Unformatted:
 System: NetBSD 4.99.63 i386
 Architecture: i386
 Machine: i386