[Lancaster] Firewall problem

[Mike Livsey]

Does your firewall have application level monitoring?

It may be that you need to specifically allow the application to be
accessed, as well as opening the relevant ports.



2009/9/22 Ken Hough <kenhough at btinternet.com>

> On Monday 21 September 2009 16:13:50 Richard Robinson wrote:
> > On Mon, Sep 21, 2009 at 02:45:38PM +0100, andy baxter wrote:
> > > Sorry I'm confused too. Did you try my suggestion of using wireshark to
> > > look at what's happening over the network when you try to connect?
> >
> > This is probably a stupid comment, I'm not a expert at this stuff & I
> > haven't really been paying much attention ... but :- it's not a question
> of
> > packet type, is it ? Does the firewall select for TCP / UDP ?
>
> I've tried enabling UDP on the firewall, but this didn't help.
>
> Recent tests as follows:
>
> 1. Accessed vsftpd locally as ftp://localhost (with the firewall enabled)
> without any problems. This confirms that vsftpd is working as I intended.
>
> 2. Accessing the vsftpd server remotely (with firewall enabled) via my
> laptop
> running Firefox under winXP again failed. On dropping the firewall on the
> server machine, again all was well.
>
> Clearly:
>
> --  there is a problem with the firewall on the server machine.
>
> --  the setup on the laptop PC is working!
>
>
> As Andy recommended, I installed 'wireshark' on the laptop machine. This
> runs
> OK, but before commenting on what I found, I'd like to spend a bit of time
> figuring out all of what it told me.
>
> It does seem that with the firewall running, I get a connection, but this
> is
> then dropped.
>
> Ho hum! Life is fun!  :-)
>
> Further investigation has shown that one or more TCP ports in the range
> 50000
> to 55000 is/are being accessed. ie if I enable this range, I get full
> access.
>
> A bit more experimentation should allow me to home in of the ports
> needed.  :-)
>
> Ken Hough
>
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