panic in sbdrop_locked

[Meno Abels]

Hello,

i have two boxes running currently freebsd-6.0-p3 i386 and they are
panic around every 24 hour once a time. I just update to -p4 so i will
see if it working better. I also didn't have the debug kernel ready so
i can only provide this very weak infos:
(kgdb) bt
#0  0xc06e5b2c in doadump ()
#1  0xc06e60c0 in boot ()
#2  0xc06e6409 in panic ()
#3  0xc0731406 in sbdrop_locked ()
#4  0xc07b373e in tcp_input ()
#5  0xc07a93fe in ip_input ()
#6  0xc077a2b9 in netisr_processqueue ()
#7  0xc077a51f in swi_net ()
#8  0xc06cbfe8 in ithread_loop ()
#9  0xc06caebf in fork_exit ()
#10 0xc090fe1c in fork_trampoline ()

Is there any procedure to track this problem down other than have a
debug kernel prepared what i done now-:) And have a very close look to
the backtrace. I saw it
happens sometimes in the development branches.

BTW The network config is quite komplex on that both crashing boxes
but very simliar.
I also have around 100 other boxes running on the same hardware with
the same os without problem but the network config is not that
complex.

re0: flags=8943<UP,BROADCAST,RUNNING,PROMISC,SIMPLEX,MULTICAST> mtu 1500
        options=8<VLAN_MTU>
        inet 172.20.20.20 netmask 0xffffff00 broadcast 172.20.20.255
        inet6 fe80::240:f4ff:fecb:9463%re0 prefixlen 64 scopeid 0x1
        inet 172.20.20.97 netmask 0xffffffff broadcast 172.20.20.97
        inet 172.20.20.89 netmask 0xffffffff broadcast 172.20.20.89
        inet 172.20.20.60 netmask 0xffffffff broadcast 172.20.20.60
        inet6 2001:XXX:XXX::3 prefixlen 64
        ether 00:40:f4:cb:94:63
        media: Ethernet autoselect (1000baseTX <full-duplex>)
        status: active
re1: flags=8843<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST> mtu 1500
        options=8<VLAN_MTU>
        inet 172.20.21.2 netmask 0xffffff00 broadcast 172.20.21.255
        inet6 fe80::240:f4ff:febb:2124%re1 prefixlen 64 scopeid 0x2
        ether 00:40:f4:bb:21:24
        media: Ethernet autoselect (10baseT/UTP)
        status: active
rl0: flags=8943<UP,BROADCAST,RUNNING,PROMISC,SIMPLEX,MULTICAST> mtu 1500
        options=8<VLAN_MTU>
        inet YY.YY.YY.215 netmask 0xffffff00 broadcast YY.YY.YY.255
        inet6 fe80::213:8fff:fe1f:6586%rl0 prefixlen 64 scopeid 0x3
        ether 00:13:8f:1f:65:86
        media: Ethernet autoselect (100baseTX <full-duplex>)
        status: active
plip0: flags=108851<UP,POINTOPOINT,RUNNING,SIMPLEX,MULTICAST,NEEDSGIANT>
mtu 1500
pfsync0: flags=41<UP,RUNNING> mtu 1348
        pfsync: syncdev: re1 maxupd: 128
pflog0: flags=41<UP,RUNNING> mtu 33208
lo0: flags=8049<UP,LOOPBACK,RUNNING,MULTICAST> mtu 16384
        inet 127.0.0.1 netmask 0xff000000
        inet6 ::1 prefixlen 128
        inet6 fe80::1%lo0 prefixlen 64 scopeid 0x7
carp240: flags=41<UP,RUNNING> mtu 1500
        inet 172.20.20.240 netmask 0xffffff00
        carp: MASTER vhid 11 advbase 1 advskew 110
carp241: flags=41<UP,RUNNING> mtu 1500
        inet 172.20.20.241 netmask 0xffffff00
        carp: BACKUP vhid 12 advbase 1 advskew 140
carp255: flags=41<UP,RUNNING> mtu 1500
        inet 172.20.20.1 netmask 0xffffff00
        carp: MASTER vhid 255 advbase 1 advskew 110
carp254: flags=1<UP> mtu 1500
        carp: INIT vhid 254 advbase 1 advskew 110
carp219: flags=41<UP,RUNNING> mtu 1500
        inet YY.YY.YY.219 netmask 0xffffff00
        carp: MASTER vhid 16 advbase 1 advskew 100
carp220: flags=41<UP,RUNNING> mtu 1500
        inet YY.YY.YY.220 netmask 0xffffff00
        carp: BACKUP vhid 17 advbase 1 advskew 130
carp20: flags=41<UP,RUNNING> mtu 1500
        inet YY.YY.YY.182 netmask 0xffffff00
        carp: BACKUP vhid 21 advbase 1 advskew 130
carp21: flags=41<UP,RUNNING> mtu 1500
        inet YY.YY.YY.183 netmask 0xffffff00
        carp: BACKUP vhid 22 advbase 1 advskew 130
carp196: flags=41<UP,RUNNING> mtu 1500
        inet YY.YY.YY.196 netmask 0xffffff00
        carp: BACKUP vhid 196 advbase 1 advskew 130
carp197: flags=41<UP,RUNNING> mtu 1500
        inet YY.YY.YY.197 netmask 0xffffff00
        carp: MASTER vhid 197 advbase 1 advskew 110
carp58: flags=41<UP,RUNNING> mtu 1500
        inet 172.20.20.58 netmask 0xffffff00
        carp: BACKUP vhid 58 advbase 1 advskew 200
carp59: flags=41<UP,RUNNING> mtu 1500
        inet 172.20.20.59 netmask 0xffffff00
        carp: BACKUP vhid 59 advbase 1 advskew 140
vlan0: flags=8943<UP,BROADCAST,RUNNING,PROMISC,SIMPLEX,MULTICAST> mtu 1500
        inet 172.20.22.2 netmask 0xffffff00 broadcast 172.20.22.255
        inet6 fe80::240:f4ff:fecb:9463%vlan0 prefixlen 64 scopeid 0x14
        ether 00:40:f4:cb:94:63
        media: Ethernet autoselect (1000baseTX <full-duplex>)
        status: active
        vlan: 22 parent interface: re0
bridge0: flags=8041<UP,RUNNING,MULTICAST> mtu 1500
        inet6 2001:XXX:XXX:2::3 prefixlen 64
        ether ac:de:48:6c:e5:2d
        priority 32768 hellotime 2 fwddelay 15 maxage 20
        member: vlan0 flags=3<LEARNING,DISCOVER>
gif0: flags=8051<UP,POINTOPOINT,RUNNING,MULTICAST> mtu 1280
        tunnel inet XX.YY.ZZ.219 --> 212.224.0.188
        inet6 fe80::240:f4ff:fecb:9463%gif0 prefixlen 64 scopeid 0x16
        inet6 2001:XXX:XXX:2bf::2 --> 2001:XXX:XXX:2bf::1 prefixlen 128

Cheers

meno