netcat is blocked, telnet gets connection

I’m trying to install an svn server on my linux machine (ubuntu 9.04). I copied a line to start svnserve to the inetd.conf file and restarted inetd. But I’m not able to connect with an svn client to the server. I always get the error message

connection refused

Now comes the strange part: If I call

netcat localhost 3690

the connection is refused, too. But if I call

telnet localhost 3690

I get some responses from svnserve.

Any ideas what could be the cause of this – and how I can make my svnserver work?

Some more details:

• I installed inetutils-inetd (Version 2:1.6-1)

• netstat gives me the line

  tcp6 0 0 :::3690 :::* LISTEN

• If I disable all the “special IPv6 addresses” in /etc/hosts, telnet stops to work and gives me a “connection refused”, too.

• I tried to activate the daytime service of inetd (port 13). Same behaviour: netcat isn’t able to connect, telnet is.
• As far as I can see there is no firewall (ufw is installed but not enabled).

Netcat only does IPv4, and the server is only listening on IPv6.

Try setting this kernel option, then killing and restarting inetd:

sysctl net.ipv6.bindv6only=0

(And change the inetd service line to tcp. About time you start using v6)

I found the answer myself…

The problem was this line in the inetd.conf:

svn stream tcp nowait subversion /usr/bin/svnserve svnserve -i -r /home/svn

After switching the keyword tcp to tcp4 everything works fine. Now netstat gives me this output:

tcp        0      0 0.0.0.0:3690            0.0.0.0:*               LISTEN