crazy network problem -- sleep?

[stutiredboy]

Adrian Penisoara 写道:
> Hi,
>
> 2009/3/1 stutiredboy <stutiredboy at gmail.com
> <mailto:stutiredboy at gmail.com>>
>
>     Adrian Penisoara 写道:
>     > Hi,
>     >
>     > 2009/3/1 stutiredboy <stutiredboy at gmail.com
>     <mailto:stutiredboy at gmail.com>
>     > <mailto:stutiredboy at gmail.com <mailto:stutiredboy at gmail.com>>>
>     >
>     > hi,all:
>     >
>     > recently , we found a problem that , some server which with FreeBSD
>     > 6.2 may stop networking after
>     > days of services, it is so difficulty express this status, e,
>     such as
>     > sleep? i can not ping this server, tracert is also
>     > failure, and other services ,network/server seems to be down... but
>     > while i insert the keyboard/mouse/crt in ,
>     > everything is ok, such as a ring to call the system to wake-up... no
>     > errors found in dmesg or /var/log/messages,
>     > such as nothing happened...orz，our unlimit args as follow:
>     >
>     > cputime unlimited
>     > filesize unlimited
>     > datasize 2088152 kbytes
>     > stacksize 65536 kbytes
>     > coredumpsize unlimited
>     > memoryuse unlimited
>     > vmemoryuse unlimited
>     > descriptors 655000
>     > memorylocked unlimited
>     > maxproc 5547
>     > sbsize unlimited
>     >
>     > plz give me some suggestion to trace the problem or solve it .
>     > thanks a
>     > lot !
>     >
>     >
>     > First you need to check whether packets are reaching the system and
>     > whether the response packets are leaving it with tcpdump(8) on the
>     > appropriate interface.
>     >
>     > If you see the packets coming but not coming out then you need to
>     > check the status of your TCP/IP stack -- e.g. post the output of
>     > "netstat -m" and "netstat -s". Also check dmesg output for any
>     errors.
>     >
>     > If you are using firewall(s) (ipfw/ipfilter/pf) then check the rules
>     > and the firewall states status; try temporarily disabling the
>     firewall
>     > (ipfw disable firewall / ipf -D / pfctl -d) and check whether your
>     > system becomes reachable.
>     >
>     > Check CPU load, interrupts, packet stats (systat -vmstat / systat
>     > -ifstat).
>     >
>     > Regards,
>     > Adrian Penisoara
>     > EnterpriseBSD
>     hi, thank you for your help, i can only ssh to the system, so
>     while the
>     network is down, i can not login in
>
>     yes, we have ipfw on , these rules have used a long time, and many
>     other
>     severs do not have this problem,
>
>     this sistutation happened scarce, in different machine rooms,
>     different
>     isps, different servers, such as hp\dell.
>
>     while the network usable, the cpu and system load is normal, i have
>     checked dmesg and syslog, nothing
>
>     special found , where our colleague in machine room insert the
>     keyboard
>     or mouse in ,then the network
>
>     recover , it is so difficult to catch the ouput of tcpdump or other
>     messages form netstat , the moment you
>
>     have the keyboard connected , the network recover... thanks very
>     much !
>
>
> You mean that once you plugin a keyboard the machine recovers ? That's
> weird. What if you leave the keyboard connected all the time ?
>
> Try to attach one of the machines which reproduces the problem to a
> KVM switch (Keyboard/Video/Mouse switcher). If you are able to
> reproduce again the problem then you might have more chances to catch it.
>
> Regards,
> Adrian.
>
hi, thanks Adrian. yes,it is weird and thanks for your opinion, it's a
good a idea , but it is a pity that i do not know which machine will run
into this problem again, we have thousands of machines in different
machine rooms, i will try this , hope i have the chances to catch the
useful info. :-)