Aage Johansen pisze:

>
>
> Vlad Khorsun wrote:
> >> First: sorry for a looooong report!
> >> I don't even know if this is the best group to post in - maybe the
> >> IBO group more relevant?
> >> Or, maybe this is stuff for the developers?
> >>
> >>
> >> We are using Firebird 1.5 SS on Windows, client application written
> >> in Delphi with IBO.
> >>
> >>
> >> Problem:
> >> Clients is disconnected (connection is "lost").
> >> I've no idea whether this is a Firebird problem, a firewall problem,
> >> or something else.
> >
> > Do you use firewall ? Or some intermediate network hardware
> between client and
> > server hosts (such as switch or hub) ? Sometime brocken HW may cause such
> > problems...
>
> Yes, there is a firewall. The network is structured into "zones".
> I'll ask if they can double check hardware (if possible). A fault in
> a switch or firewall (or a misbehaving network adapter) could be
> corrupting package, obviously.
> Clients and db-server never had this sort of problem before the
> network was restructured and some new boxes (internal firewall and
> new switches) were installed.
>
> >
> >> The network people did some tracing to see what was going on - see
> >> traces below.
> >> The Firewalls are Juniper, and the trace program is called
> WireShark (I think).
> >> I hope the trace is of use (it's way beyond my knowledge).
> >>
> >> The problem with "lost connection" was observed during the trace.
> >> Any hint toward solving the problem is appreciated.
> >>
> >> Remark:
> >> I thought that the only port used would be 3050, but it looks like
> >> some other port is used as well. In the trace below port 1887 seems
> >> to be in use for something (in the second trace port 2225 is in
> >> use). I don't know if this is of any importance, though.
> > ...
> >
> > I didn't found any important info in trace, sorry
>
> If you think more trace info would help, I will try to provide it. I
> have a trace with about 80 frames where there are 2 instances of
> "Malformed packet".
>
> >
> >> If it is a firewall problem, I would nevertheless like a comment on
> >> the port numbers (1887 and 2225) and the "Malformed Packet"
> bit. If possible.
> >
> > TCP\IP connection have two endpoints. Port number of server endpoint
> > is fixed and good known (3050 in case of Firebird). Port number of client
> > endpoint is choosen by OS and have no meaning.
>
> Does the OS choose random port numbers? Doesn't this make it
> difficult to specify (to the firewall) which ports to keep
> open/accesible? Can a fixed port number be specified? Or, this is
> irrelevant?
>
> >
> > As for "Malformed Packet" bit... If some packet have wrong
> content then connection
> > will be terminated by Firebird with corresponding record in
> firebird.log. In the worst case
> > AV may happen (i don't remember if it was fixed in FB 1.5.5). But
> i don't understand
> > who is decided that packet is malformed - firebird or tracing sw ?
>
> I don't know. Again, I'll have to ask the network group. And
> recheck the Firebird log.
>
> Thanks for answers and comments. I will discuss this with the
> network group and see if they can come up with some new ideas (or
> anything else!).
>
> Regards,
> Aage J.
>

Check also network card and connection settings.


Boguslaw