sshd and IPv6

M

minimike

Hi there,

Could it be possible that the sshd in the base system can't handle IPv6?

In /etc/ssh/sshd_config I have written:

Code: 
Port 22
AddressFamily any
ListenAddress 0.0.0.0
ListenAddress ::

On my laptop nmap shows me the port is open but if I want log in with ssh like this:

Code: 
ssh -6 username@MY_IPv6_ADRESS

nothing happens. The server is proper available over IPv6 and a firewall doesn't block SSH. SSH over IPv4 works. I'm using FreeBSD 8 stable on my server and Debian 6 on my laptop as client.
 
How long does not happen anything? If it's about 30-120 seconds, it may be a DNS resolution related problem.
Try setting 'UseDNS no' in /etc/ssh/sshd_config on the server to disable this check and skip the delay.
 
minimike said:
Hi there,

Could it be possible that the sshd in the base system can't handle IPv6?
Click to expand...

No, it definately works.

In /etc/ssh/sshd_config I have written:

Code: 
Port 22
AddressFamily any
ListenAddress 0.0.0.0
ListenAddress ::
Click to expand...

But 0.0.0.0 and :: are not valid IPv4 or IPv6 addresses, what are you trying to achieve? If you set these to valid addresses I'm sure it will work...

thanks Andy.

PS ok, in theory :: is all IPv6. But what happens if you don't comment this out? As I have done....

PPS you did try pinging your IPv6 address didn't you?
 
AndyUKG said:
But 0.0.0.0 and :: are not valid IPv4 or IPv6 addresses, what are you trying to achieve? If you set these to valid addresses I'm sure it will work...
Click to expand...

It's fine to use 0.0.0.0, it's the same as INADDR_ANY, a listening address used by default by many server programs, see /usr/include/netinet/in.h. Same rules apply for IP version 6, '::' means INADDR_ANY for IP version 6.
 
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