Hi Guys

I have some unexpected behaviour from my ntopng installation. I've very
recently started using ntopng, so I'm not sure if what I'm observing is
correct or an issue.

I'm running an instance ntopng that I built from r7148 on Raspberry Pi.
I've configured ntopng to listen to an interface (interface 3, eth1) that
is a port mirror of my WAN connection via a Netgear GS108E switch. The
connection is lightly loaded at approx 100MB over 30 mins.

Is the following behaviour working correctly ... ?

Packet data is accumulated. Looking at a particular host via the web
interface, all looks good. I can see sensible total traffic, protocols,
activity patterns, ASN, geo, etc. The behaviour I'm interested in occurs
when the host drops from cache due to lack of recent activity -- maybe even
after just a few minutes of inactivity.

If I search for the host using the search input box on the main web
interface, the returned web page correctly states that the host is not in
cache and provides a link to force the return of the host information from
cache. If I select the link, the host information re-appears (note there is
sometimes a grey busy icon along side the ip address for a few seconds -- I
assume to indicate that the host info is being retrieved). So far so good.

However, the host information is missing the previous data.

If I now force the host to generate packets (eg browse a web site from the
host), the original host (before the cache miss) data reappears. However,
under these circumstances, the "First Seen" time is as of the most recent
set of packets -- even though the traffic and the protocol tabs "correctly"
contain the full set of information since ntopng was restarted. (Obviously,
I'm assuming this information is correct -- at the very least it appears
sensible).

In addition once this state has occurred the "historical" tab contains
incorrect information. The exact state of "incorrectness" is variable, but
most often the manifestation is that the "Total Traffic" information is
lower than the original total traffic before the cache miss, but often much
more than the traffic that has occurred since the recent "First Seen" time.
ie it sits somewhere between the two.

BTW The above behaviour is repeatable and I've now seen it four times
despite reboots and rebuilds.

So is the above correct behaviour? I'm assuming it is incorrect; I would
have assumed that the search return from cache should have re-instantiated
the cache miss data in the first place. If the behaviour is not correct, is
there any recommended approach I should take to debug it ? I looked for an
option to debug build ntopng but didn't find one.

Anyhow, I'm really liking the ntopng so far. It looks great and has already
helped me achieve part of my aim of figuring out the cause of some
unexplained bandwidth usage at Chez Bartlett.

Thx
Neil Bartlett
_______________________________________________
Ntop mailing list
[email protected]
http://listgateway.unipi.it/mailman/listinfo/ntop

Reply via email to