"ftp ftp://ftp.netbsd.org/pub/NetBSD/" from a NAT client,

226 Transfer complete.
ftp> bye
221-

421 Service not available, remote server timed out. Connection closed
[hauke@q700] ~ >

and then

[hauke@pizza] / # panic: m_copydata
Stopped at      netbsd:cpu_Debugger+0x4:        or              %o7, %g0, %g1
db{0}> t
cpu_Debugger(0xf0248860, 0xf0243cd8, 0x100, 0x2, 0xf0c29b60, 0xf027ec00) at netbsd:m_copydata+0xa4
m_copydata(0x0, 0x0, 0x28, 0xf0dbc764, 0x1ad4, 0xf0299d24) at netbsd:ipllog+0x1b4
ipllog(0x0, 0x4, 0xf02744f8, 0xf0274500, 0xf0274508, 0x2) at netbsd:ipflog+0x1ec
ipflog(0xf02745e8, 0x40008111, 0x0, 0xf027b400, 0xf027b400, 0xf027a800) at netbsd:fr_dolog+0x9c
fr_dolog(0xf02745e8, 0xf02745e4, 0xf02745e8, 0x40000000, 0x17, 0x14) at netbsd:fr_check+0x2f8
fr_check(0xf0c30950, 0x14, 0xf0c26200, 0x0, 0xf0274754, 0x1e3a40) at netbsd:fr_check_wrapper+0x60
fr_check_wrapper(0xf0c30950, 0xf0274754, 0xf0c25000, 0x1, 0x0, 0xffff) at netbsd:pfil_run_hooks+0x60
pfil_run_hooks(0xf02d17b4, 0xf0274814, 0xf0c25000, 0x1, 0x0, 0xf0c30964) at netbsd:ip_input+0xbb8
ip_input(0xf0c30900, 0xff, 0x1000000, 0x2000, 0x0, 0x1c70e0) at netbsd:ipintr+0x88
ipintr(0xf02ded64, 0xf02433e0, 0x356, 0x0, 0x40100, 0x68840) at netbsd:softnet+0x7c
softnet(0xf0274900, 0xf01f399c, 0x100, 0x408000e7, 0x538, 0x100) at 0xf00066c0
0xf00066c0(0xf027e6c0, 0xf0245a68, 0x292, 0x0, 0x5f400, 0x5f400) at netbsd:switchexit+0x100
db{0}>