network keep droping

[Izwan Mohd]

Update:

just got back from the remote site and checked the following:

1. tcpdump on the interface only show switch broadcast nothing more
2. the connection restored by doing arp -ad && ping <IP>

On Thu, Jun 5, 2008 at 12:27 PM, Izwan Mohd <zuan at mylinux.net.my> wrote:

>
> First question would be:  What has changed?
>>
>> Are you able to identify when the problem occurs?  This might let you
>> associate the problem with an internal cronjob or network activity.
>
>
> it randomly happen so I can't determine when it happen my cron script just
> try to ping and if it not successfull it will flush and restart the network
>
>>
>> What does ifconfig report?  Does the interface look normal or is it
>> reporting something strange?
>
>
> ifconfig does not show any abnormality but maybe I will double check it
>
> Is the switch reporting any events associated with your port?
>>
>
> Nope no  report  from switch indicating something wrong the the port that
> the machine are using
>
>
>> What do you see if you tcpdump the interface whilst its not working?
>> Are you seeing normal subnet broadcast traffic?  Unicast traffic
>> directed to your box?  Outgoing traffic from your box?
>>
>
> I will check this one this afternoon  because the machine is dead again
> I'll post the finding  later on
>
>
>>
>> Does physically unplugging and re-connecting the network cable
>> correct the problem?  Are you able to (temporarily) use a different
>> swichport or NIC?
>>
>
> sometime it does sometime it wont, already try changing to other port on
> the switch still the same, changing the NIC is not an option for me because
> it a rack mount server using on board NIC and no extra slot to add a new
> network card on it.
>
>
>> Finally, more detail on your configuration might trigger someone's
>> memory: What version of 6.x?  What NIC/MII?  How much memory?  What
>> network features (vlan, firewall, dummynet, netgraph, carp, ...) are
>> you using?
>>
>
> The server using FreeBSD 6.0-RELEASE the NIC is intel i can't remember the
> model but freebsd detect it as "em0" the server memory is 1GB, not special
> network fetures it only running snort and nessus
>
> will post more detail after I check the machine this afternoon
>
> Thank You,
>
> Regards,
> Zuan
>
>>
>> --
>> Peter Jeremy
>> Please excuse any delays as the result of my ISP's inability to implement
>> an MTA that is either RFC2821-compliant or matches their claimed
>> behaviour.
>>
>