identd problem on IRC

I have a debian linux stable.
The machine is connect to the internet via router with nat , port 113 is
forwarded to the linux box.

Identd is installed and I have this line in inetd.conf:

auth stream tcp nowait nobody /usr/sbin/in.identd in.identd

I connect to irc with a command line client like irssi or Bitchx to dalnet
or efnet and I always get:

No Ident response

In netstat -atn:

tcp 0 0 0.0.0.0:113 0.0.0.0:* LISTEN

I cannot find out the problem, have you got any idea?

Thank you.

sinapsi wrote:
> I have a debian linux stable.
> The machine is connect to the internet via router with nat , port 113 is
> forwarded to the linux box.

I have the exact set up. A Debian Sid, and I run oidentd and use irssi
to connect to irc servers.

> Identd is installed and I have this line in inetd.conf:
>
> auth stream tcp nowait nobody /usr/sbin/in.identd in.identd
>
> I connect to irc with a command line client like irssi or Bitchx to dalnet
> or efnet and I always get:
>
> No Ident response

This is because your NAT translates the local port to a different port.
I have the same issue, here is some log from my NAT (Cisco router thingy):

10.0.0.10:37626 xx.xx.xx.xx:31661 4770 0x00046 tcp eth0 wan0-0

When EFNet now asks my oidentd at port 113 it will issue the command:

31661, 6667

but it should send:

37626, 6667

Protocol fetched from RFC 1413
http://www.cse.ohio-state.edu/cgi-bin/rfc/rfc1413.html

> In netstat -atn:
>
> tcp 0 0 0.0.0.0:113 0.0.0.0:* LISTEN
>
> I cannot find out the problem, have you got any idea?

The problem is the router, really not sure how to make the ports be
transperent.

--
Regards
Hans-Christian Egtvedt

In article <9Ha7d.37389$35.1754899@news4.tin.it>, sinapsi wrote:
>The machine is connect to the internet via router with nat , port 113 is
>forwarded to the linux box.

That NAT router may be your problem.

>Identd is installed and I have this line in inetd.conf:

Looks OK

>I connect to irc with a command line client like irssi or Bitchx to dalnet
>or efnet and I always get:
>
>No Ident response

So fire up tcpdump and see what's happening. If the NAT box is also
masquerading the port numbers (such that your outbound IRC session is
changed to a different source port, identd is going to fail, because
the ident query asks "who is on your port XXX connecting to my port YYY"
and your Debian box isn't trying to connect _from_ XXX - it's really on
JJJJ.

Old guy

The strage thing is that if I connect to IRC with XP and mirc identd works
and I get recognized, so I don't think is a problem of the router.
And it works on windows even if I dodn't do port forwarding. It just take
some more time to get identified when port 113 is not forwarded but it
works.

"Hans-Christian Egtvedt" <hc@egtvedt.no> ha scritto nel messaggio
news:cjjnv9$il1$1@orkan.itea.ntnu.no...
> sinapsi wrote:
> > I have a debian linux stable.
> > The machine is connect to the internet via router with nat , port 113 is
> > forwarded to the linux box.
>
> I have the exact set up. A Debian Sid, and I run oidentd and use irssi
> to connect to irc servers.
>
> > Identd is installed and I have this line in inetd.conf:
> >
> > auth stream tcp nowait nobody /usr/sbin/in.identd in.identd
> >
> > I connect to irc with a command line client like irssi or Bitchx to
dalnet
> > or efnet and I always get:
> >
> > No Ident response
>
> This is because your NAT translates the local port to a different port.
> I have the same issue, here is some log from my NAT (Cisco router thingy):
>
> 10.0.0.10:37626 xx.xx.xx.xx:31661 4770 0x00046 tcp eth0 wan0-0
>
> When EFNet now asks my oidentd at port 113 it will issue the command:
>
> 31661, 6667
>
> but it should send:
>
> 37626, 6667
>
> Protocol fetched from RFC 1413
> http://www.cse.ohio-state.edu/cgi-bin/rfc/rfc1413.html
>
> > In netstat -atn:
> >
> > tcp 0 0 0.0.0.0:113 0.0.0.0:*
LISTEN
> >
> > I cannot find out the problem, have you got any idea?
>
> The problem is the router, really not sure how to make the ports be
> transperent.
>
> --
> Regards
> Hans-Christian Egtvedt

There is no NAT box . NAT is done from the router alcatel speedtouch pro.
The port forwarding is set on the router to forward all the call from port
113 to my linux box on port 113.


"Moe Trin" <ibuprofin@painkiller.example.tld> ha scritto nel messaggio
news:slrncls8q0.jh.ibuprofin@atlantis.phx.az.us...
> In article <9Ha7d.37389$35.1754899@news4.tin.it>, sinapsi wrote:
> >The machine is connect to the internet via router with nat , port 113 is
> >forwarded to the linux box.
>
> That NAT router may be your problem.
>
> >Identd is installed and I have this line in inetd.conf:
>
> Looks OK
>
> >I connect to irc with a command line client like irssi or Bitchx to
dalnet
> >or efnet and I always get:
> >
> >No Ident response
>
> So fire up tcpdump and see what's happening. If the NAT box is also
> masquerading the port numbers (such that your outbound IRC session is
> changed to a different source port, identd is going to fail, because
> the ident query asks "who is on your port XXX connecting to my port YYY"
> and your Debian box isn't trying to connect _from_ XXX - it's really on
> JJJJ.
>
> Old guy
>

Yes it looks like it's a router problem.
Infact if I telnet from an other local machine to the identd server port 113

I have a tcpdump:

14:16:30.475474 IP 10.0.0.4.49341 > zam.zam.auth: S 4176684133:4176684133(0)
win 5840 <mss 1460,sackOK,timestamp 1450357402[|tcp]>
14:16:30.476205 IP zam.zam.auth > 10.0.0.4.49341: S 344076484:344076484(0)
ack 4176684134 win 5792 <mss 1460,sackOK,timestamp 1086145[|tcp]>
14:16:30.476574 IP 10.0.0.4.49341 > zam.zam.auth: . ack 1 win 5840
<nop,nop,timestamp 1450357402 1086145>
14:16:34.674830 IP 10.0.0.4.49341 > zam.zam.auth: P 1:9(8) ack 1 win 5840
<nop,nop,timestamp 1450357822 1086145>
14:16:34.674947 IP zam.zam.auth > 10.0.0.4.49341: . ack 9 win 5792
<nop,nop,timestamp 1086565 1450357822>
14:16:34.685178 IP zam.zam.auth > 10.0.0.4.49341: P 1:35(34) ack 9 win 5792
<nop,nop,timestamp 1086566 1450357822>
14:16:34.685685 IP 10.0.0.4.49341 > zam.zam.auth: . ack 35 win 5840
<nop,nop,timestamp 1450357823 1086566>
14:16:34.689107 IP zam.zam.auth > 10.0.0.4.49341: F 35:35(0) ack 9 win 5792
<nop,nop,timestamp 1086567 1450357823>
14:16:34.689597 IP 10.0.0.4.49341 > zam.zam.auth: F 9:9(0) ack 36 win 5840
<nop,nop,timestamp 1450357823 1086567>
14:16:34.689728 IP zam.zam.auth > 10.0.0.4.49341: . ack 10 win 5792
<nop,nop,timestamp 1086567 1450357823>

When I connect to the dalnet irc server I have no dump at all on port 113

The strange thing is that identd works when I connect from the other PC with
windows and Mirc to dalnet.
The connection pass trough the same router.

"sinapsi" <info@zam.it> ha scritto nel messaggio
news:ZDq7d.43521$35.2034455@news4.tin.it...
> There is no NAT box . NAT is done from the router alcatel speedtouch pro.
> The port forwarding is set on the router to forward all the call from port
> 113 to my linux box on port 113.
>
>
> "Moe Trin" <ibuprofin@painkiller.example.tld> ha scritto nel messaggio
> news:slrncls8q0.jh.ibuprofin@atlantis.phx.az.us...
> > In article <9Ha7d.37389$35.1754899@news4.tin.it>, sinapsi wrote:
> > >The machine is connect to the internet via router with nat , port 113
is
> > >forwarded to the linux box.
> >
> > That NAT router may be your problem.
> >
> > >Identd is installed and I have this line in inetd.conf:
> >
> > Looks OK
> >
> > >I connect to irc with a command line client like irssi or Bitchx to
> dalnet
> > >or efnet and I always get:
> > >
> > >No Ident response
> >
> > So fire up tcpdump and see what's happening. If the NAT box is also
> > masquerading the port numbers (such that your outbound IRC session is
> > changed to a different source port, identd is going to fail, because
> > the ident query asks "who is on your port XXX connecting to my port YYY"
> > and your Debian box isn't trying to connect _from_ XXX - it's really on
> > JJJJ.
> >
> > Old guy
> >
>
>

On Sat, 02 Oct 2004 08:10:29 GMT, "sinapsi" <info@zam.it> wrote:

>Yes it looks like it's a router problem.
>Infact if I telnet from an other local machine to the identd server port 113
>
>I have a tcpdump:
>
>14:16:30.475474 IP 10.0.0.4.49341 > zam.zam.auth: S 4176684133:4176684133(0)
>win 5840 <mss 1460,sackOK,timestamp 1450357402[|tcp]>
>14:16:30.476205 IP zam.zam.auth > 10.0.0.4.49341: S 344076484:344076484(0)
>ack 4176684134 win 5792 <mss 1460,sackOK,timestamp 1086145[|tcp]>
>14:16:30.476574 IP 10.0.0.4.49341 > zam.zam.auth: . ack 1 win 5840
><nop,nop,timestamp 1450357402 1086145>
>14:16:34.674830 IP 10.0.0.4.49341 > zam.zam.auth: P 1:9(8) ack 1 win 5840
><nop,nop,timestamp 1450357822 1086145>
>14:16:34.674947 IP zam.zam.auth > 10.0.0.4.49341: . ack 9 win 5792
><nop,nop,timestamp 1086565 1450357822>
>14:16:34.685178 IP zam.zam.auth > 10.0.0.4.49341: P 1:35(34) ack 9 win 5792
><nop,nop,timestamp 1086566 1450357822>
>14:16:34.685685 IP 10.0.0.4.49341 > zam.zam.auth: . ack 35 win 5840
><nop,nop,timestamp 1450357823 1086566>
>14:16:34.689107 IP zam.zam.auth > 10.0.0.4.49341: F 35:35(0) ack 9 win 5792
><nop,nop,timestamp 1086567 1450357823>
>14:16:34.689597 IP 10.0.0.4.49341 > zam.zam.auth: F 9:9(0) ack 36 win 5840
><nop,nop,timestamp 1450357823 1086567>
>14:16:34.689728 IP zam.zam.auth > 10.0.0.4.49341: . ack 10 win 5792
><nop,nop,timestamp 1086567 1450357823>
>
>When I connect to the dalnet irc server I have no dump at all on port 113
>
>The strange thing is that identd works when I connect from the other PC with
>windows and Mirc to dalnet.
>The connection pass trough the same router.

That's because mIRC doesn't care about the port numbers like oidentd does,
it just returns whatever string you specified as ident.