CentOS - Jun 2012 - OT - Is there a package to monitor network traffic

We have a situation here that is a real mystery.

Our MRTG on our outgoing router  and a firewall server that protects our 
web servers is showing a spike every six hours. I can't find the server 
behind the firewall that is generating such an extreme amount of 
packets, even though I've looked through the crontabs of nearly all 
servers, performed "ps" variations, and other types of investigation.

Is there any type of package I can install that will monitor traffic and 
report abnormal, over-threshold packets similar to what wireshark might 
do in a manner that would allow me to determine where these packets 
might be going or from where they originate?

Thanks for any help.

steve campbell

How about tcpdump?

Mike

On 06/14/2012 01:07 PM, Steve Campbell wrote:
> We have a situation here that is a real mystery.
>
> Our MRTG on our outgoing router  and a firewall server that protects our
> web servers is showing a spike every six hours. I can't find the server
> behind the firewall that is generating such an extreme amount of
> packets, even though I've looked through the crontabs of nearly all
> servers, performed "ps" variations, and other types of
investigation.
>
> Is there any type of package I can install that will monitor traffic and
> report abnormal, over-threshold packets similar to what wireshark might
> do in a manner that would allow me to determine where these packets
> might be going or from where they originate?
>
> Thanks for any help.
>
> steve campbell
>
> _______________________________________________
> CentOS mailing list
> CentOS at centos.org
> http://lists.centos.org/mailman/listinfo/centos

On Thu, Jun 14, 2012 at 12:07 PM, Steve Campbell <campbell at
cnpapers.com> wrote:
> We have a situation here that is a real mystery.
>
> Our MRTG on our outgoing router ?and a firewall server that protects our
> web servers is showing a spike every six hours. I can't find the server
> behind the firewall that is generating such an extreme amount of
> packets, even though I've looked through the crontabs of nearly all
> servers, performed "ps" variations, and other types of
investigation.
>
> Is there any type of package I can install that will monitor traffic and
> report abnormal, over-threshold packets similar to what wireshark might
> do in a manner that would allow me to determine where these packets
> might be going or from where they originate?
If you can catch it while the event is happening, wireshark can help
you analyze the traffic.  Do a short capture, then
Statistics/Converstation list/ipv4 (or endpoint/ipv4) will give you a
sortable list of the bulk of the traffic.

If you are monitoring the traffic on all interfaces and switch ports
with SNMP (Cacti/OpenNMS etc.) you would probably see it too.  OpenNMS
generates nightly reports of 'top 20' interface usage although backups
sometimes show up there.   'Ntop' is also good at identifying traffic
and can summarize in different ways, but you have to run it on the
server where the traffic is happening.

-- 
   Les Mikesell
     lesmikesell at gmail.com

On Jun 14, 2012, at 1:07 PM, Steve Campbell <campbell at cnpapers.com>
wrote:
> We have a situation here that is a real mystery.
> 
> Our MRTG on our outgoing router  and a firewall server that protects our 
> web servers is showing a spike every six hours. I can't find the server
> behind the firewall that is generating such an extreme amount of 
> packets, even though I've looked through the crontabs of nearly all 
> servers, performed "ps" variations, and other types of
investigation.
> 
> Is there any type of package I can install that will monitor traffic and 
> report abnormal, over-threshold packets similar to what wireshark might 
> do in a manner that would allow me to determine where these packets 
> might be going or from where they originate?
Setup a nettop server and netflow on the routing interfaces and you will find
tour culprit.

-Ross

On 14/06/2012 18:07, Steve Campbell wrote:
> We have a situation here that is a real mystery.
>
> Our MRTG on our outgoing router  and a firewall server that protects our
> web servers is showing a spike every six hours. I can't find the server
> behind the firewall that is generating such an extreme amount of
> packets, even though I've looked through the crontabs of nearly all
> servers, performed "ps" variations, and other types of
investigation.
>
> Is there any type of package I can install that will monitor traffic and
> report abnormal, over-threshold packets similar to what wireshark might
> do in a manner that would allow me to determine where these packets
> might be going or from where they originate?
> tp://lists.centos.org/mailman/listinfo/centos
I used to quite like iptraf for a quick summary view of the traffic use. 
Don't know if there is a CentOS package for it.

-- 
Regards,

Giles Coochey, CCNA, CCNAS
NetSecSpec Ltd
+44 (0) 7983 877438
http://www.coochey.net
http://www.netsecspec.co.uk
giles at coochey.net