UDPing where UDP is blocked (Formally TCPing)

James E. Flemer jflemer at acm.jhu.edu
Thu Nov 7 13:46:36 EST 2002


GRE := Generic Routing Encapsulation[1]
RPI := Rensselaer Polytechnic Institute[2]
MTU := Maximum Transmit Unit[?]

[1] http://www.faqs.org/rfcs/rfc2784.html
[2] http://www.rpi.edu/



On Thu, 7 Nov 2002, Chris Weiland wrote:

> Ok, so I know what JHU and IP stand for, but WTF are GRE, RPI, and MTU?  I
> don't even know what UDP stands for!  Stop it with the TLAs!! (Three Letter
> Acronyms)
> I'm a newbie to networking stuff, so I don't even know how to tunnel (maybe
> a topic for an ACM meeting?) Anyway, this whole "people can't connect to me
> because ports are blocked" thing is getting really annoying, so any help
> would be appreciated.
>
> Chris
>
>
> ----- Original Message -----
> From: "James E. Flemer" <jflemer at jhu.edu>
> To: <acm at acm.jhu.edu>
> Sent: Thursday, November 07, 2002 11:12 AM
> Subject: Re: UDPing where UDP is blocked (Formally TCPing)
>
>
> Does JHU block GRE and/or IPsec packets? If not, you should
> just set up some tunnel to something off campus. RPI is
> very annoying, they block GRE and IPsec. Grrr. If you use
> GRE and IP-over-IP there is farily low overhead, your
> tunnel has to have a slightly lower MTU than 1500, but not
> much. Later,
> -James
>
>
> On Thu, 7 Nov 2002, Chris Weiland wrote:
>
> > Are there any UDP ports (hopefully that have a TCP port under it) that
> would
> > NOT block incoming traffic?  Or, do i have to just do a portscan?  =]
> >
> > Chris
> > ----- Original Message -----
> > From: "Albert Lee" <trisk at jhu.edu>
> > To: <acm at acm.jhu.edu>
> > Sent: Monday, November 04, 2002 8:38 PM
> > Subject: Re: TCPing where TCP is blocked
> >
> >
> > -----BEGIN PGP SIGNED MESSAGE-----
> > Hash: SHA1
> >
> > Well, TCP port 23 and the rest of the usual reserved services ports aren´t
> > blocked by HITS, but I suspect incoming packets to most UDP ports,
> including
> > port 23 (which has no relation to telnet), would be.
> >
> > I´d be interested in testing the game in my (somewhat limited) spare time.
> >
> > - -Albert
> >
> > On Tue, 05 Nov 2002 11:48, Chris Weiland wrote:
> > > I was just wondering if there is a way to get a hosted game server
> through
> > > the firewall.  I'd like to host a server now and then for the game I'm
> > > working on (http://hobbiticus.acm.jhu.edu) but whenever I do, no one can
> > > connect to it outside of school.  It runs (well, supposed to run) on
> port
> > > 28000, but you can change it.  It also uses the UDP port that's the TCP
> > > port + 1.  I thought that maybe if I host on TCP port 22 (SSH), then
> using
> > > port 23 (Telnet) that it might get through, but it didn't.  Or, at least
> > it
> > > didn't show up on the master server listing, where you have to broadcast
> > on
> > > port 28000 to get listed.  Any help would help us test our game.  BTW,
> we
> > > will be looking for (trustworthy) testers for a closed beta in the next
> > few
> > > weeks, so contact me if you're interested.
> > >
> > > Chris Weiland
> > -----BEGIN PGP SIGNATURE-----
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> > S8gW9cQ2mQ2UYy6byaV/Sl0=
> > =MxiS
> > -----END PGP SIGNATURE-----
> >
> >
>
>
>
>
>





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