[Dxspider-support] console.pl

[Brendan Minish]

On Mon, 2011-04-04 at 21:12 +0100, Dirk Koopman G1TLH wrote:
> On 04/04/11 18:13, Brendan Minish wrote:
> > I ran into a similar problem a while back on a centos install
> >
> > these days localhost (in /etc/hosts ) also has an ipv6 loopback address
> > but console.pl does not support ipv6 yet
> 
> Which is interesting, seeing as console.pl and cluster.pl use the same 
> routine for socket access whether for IPV4 or IPV6 sockets. I wonder 
> whether you could narrow the problem down a bit for me?

Sure, I can either just give you (root) access to a test node running on
a centos virtual machine that has ipv6 set up or I can test things under
your guidance 

The cluster supports user logins just fine under ipv6 whilst
simultaneously supporting ipv4 ,I am not sure how an IPv6 IP address
gets exported to the rest of the network though, check for EI7IG in your
logs if curious about this  

as far as cluster peering, I have not tested it yet but W1NR has asked
to peer over IPv6 so I guess we will know shortly.. 

If I change (in DXvars)
$clusteraddr = "127.0.0.1";
to 
$clusteraddr = "::1";
console.pl can't connect 
 
[sysop at dhcp-236 spider]$ ./perl/console.pl 
Sorry, the cluster EI7MRE-5 is currently off-line


# netstat -tnlpn
Active Internet connections (only servers)
Proto Recv-Q Send-Q Local Address               Foreign Address             State       PID/Program name   
tcp        0      0 0.0.0.0:111                 0.0.0.0:*                   LISTEN      1704/portmap        
tcp        0      0 0.0.0.0:692                 0.0.0.0:*                   LISTEN      3478/rpc.statd      
tcp        0      0 127.0.0.1:25                0.0.0.0:*                   LISTEN      2036/sendmail: acce 
tcp        0      0 :::7300                     :::*                        LISTEN      8002/perl           
tcp        0      0 ::1:27754                   :::*                        LISTEN      8002/perl           
tcp        0      0 :::22                       :::*                        LISTEN      3517/sshd         

So it looks like the cluster is listening ok for console on ipv6, but is
it also listening for ipv4 as it is supposed to 


If I then change DXVars whilst the CLX is running back to 127.0.0.1 the
console fails silently 

Telnet reveals a little more 

[sysop at dhcp-236 spider]$ ./perl/console.pl 
Sorry, the cluster EI7MRE-5 is currently off-line
[sysop at dhcp-236 spider]$ vi local/DXVars.pm 
[sysop at dhcp-236 spider]$ ./perl/console.pl 
[sysop at dhcp-236 spider]$ ./perl/console.pl 
[sysop at dhcp-236 spider]$ ./perl/console.pl 
[sysop at dhcp-236 spider]$ telnet 127.0.0.1 27754
Trying 127.0.0.1...
telnet: connect to address 127.0.0.1: Connection refused
telnet: Unable to connect to remote host: Connection refused
[sysop at dhcp-236 spider]$ telnet ::1 27754
Trying ::1...
Connected to localhost6.localdomain6 (::1).
Escape character is '^]'.
^]
telnet> quit
Connection closed.
[sysop at dhcp-236 spider]$ 


So it appears that the cluster.pl will listen for console on either IPv6
or IPv4 but not both at once and that console.pl fails silently when
asked to connect over ipv6 


> The original problem used to be that Redhat decided to have localhost 
> default to '::1' - something I have just noticed that Ubuntu Maverick is 
> also trying on now.

Well, it's more a case of adding an IPv6 address for loopback, ipv6
enabled 'things' will prefer ipv6 over ipv4 if they think they support
it. 
Most Ipv6 issues that I have seen to date have either been with boxes
that think they have IPv6 connectivity but don't, or applications that
have IPv6 issues but think that they can do IPv6 

-- 
73
Brendan EI6IZ