Ports doubt, check network performance...?

[perikillo]

On 7/5/06, Nikos Vassiliadis <nvass at teledomenet.gr> wrote:
> On Wednesday 05 July 2006 02:01, perikillo wrote:
> > On 7/4/06, Nikos Vassiliadis <nvass at teledomenet.gr> wrote:
> > > On Tuesday 04 July 2006 03:49, perikillo wrote:
> > > >    Hi people.
> > > >
> > > >     I have some problems on my network, and i want to use my freebsd
> > > > box to see if i can find the problems on my network, we have two
> > > > networks in two countrys connected by a private link, but i have seen
> > > > just a couple a weeks ago that we have some problems between both
> > > > links, we are lossing packets if i ping some server on the other link,
> > > > some times i get 36% of packets loss, is to but to much on bussines
> > > > hours.
> > >
> > > 36% packet loss is very high, it will almost make TCP unusable.
> > > ping is your tool. Use -s 500 to 1500 to simulate some-how real traffic
> > > situation. I guess you have a point-to-point link between the two
> > > offices, connected to a router? Do you administer these routers? Do know
> > > your bandwidth utilization? Are you sure your link is OK? check this with
> > > your service provider.
> > >
> > > Either you link is bad or you use all your available bandwidth.
> > >
> > > >     I want to use my freebsd box running 6.0 but just want to know if
> > > > some one could recomend me wich ports to check to see if i can find
> > > > wich device is causing this problem.
> > >
> > > FreeBSD can not help you much with this. Unless FreeBSD is the router
> > > in question. Or you could pass all traffic from a FreeBSD box in order to
> > > know what's going on. something like this
> > >
> > > central-switch------FBSD------router-1=====router-2
> > > [--------------------LAN--------------------] [-----WAN-----]
> >
> >    No i dont administer those routers, i need to check if the problem
> > is our network or the ISP link, and yes is Point To Point link and
> > talk with the guys that setup that router, but im thinking in put a
> > freebsd box between our lan and the router and sniff all the traffic
> > and see whats is happening but wich port to use...?
>
> ntop can show how much bandwidth is used by whom
> There are many available and I'm not sure ntop is the
> best choice. There is pfSense which is a FreeBSD based
> live-CD for router-like installations. pfSense has ntop
> package. it won't hurt trying it out.
>
> > , thanks all for
> > your help.
> >
> >    Ethereal is for read packets but can he check wich one device is
> > causing problems..?
>
> device causing problems? Do you mean computer using
> a lot of bandwidth? You can check this with ntop(and a thousand
> others I guess, use google)
>

   Well to find how is causing my loss of packets, iam using ntop
right now and ethereal, i try to find out who is causing the lost of
packets, any recomendations...?

   Thanks for your time!!!