The following reply was made to PR kern/32900; it has been noted by GNATS.

From: Pavel Cahyna <pavel.cahyna@st.mff.cuni.cz>
To: gnats-bugs@netbsd.org
Cc: 
Subject: Re: kern/32900 (Full-size packets get truncated by 4 bytes when using vlan(4).)
Date: Sun, 9 Apr 2006 09:07:33 +0200

 The (g)sip driver optimizes the ioctl method: for SIOCSIFFLAGS, it
 compares the new flags with the old flags and avoids reset if there are
 only certain changes.
 
 It does not take into account, though, that there is other state which can
 change and it needs to reset the hardware somehow. Namely, if_capenable,
 ec_capenable and ec_nvlans. For all three, the _init method must program
 the chip specially.