Pass wordless ssh over IPv6

skimeer · 01-14-2013, 07:05 AM

Hello,

I want to enable passwordless ssh over IPv6 in dual stack (both IPv4 and IPv6 coexist) environment.

ssh-keygen by default using hostname from /etc/hosts file.

I have enabled IPv6 on my machine and able to self ssh with IPv6 ip.

Code:

[root@test ~]# ssh fe80::20c:29ff:fe18:687c%eth0
Address fe80::20c:29ff:fe18:687c%eth0 maps to test6, but this does not map back to the address - POSSIBLE BREAK-IN ATTEMPT!
root@fe80::20c:29ff:fe18:687c%eth0's password:
Last login: Mon Jan 14 07:59:08 2013 from fe80::20c:29ff:fe18:687c%eth0
[root@test ~]#

However ssh is not working with host name,though my /etc/hosts has entries.

Code:

[root@test ~]# cat /etc/hosts
### beginning of base hosts configuration ###
127.0.0.1 localhost
::1       localhost6.localdomain6 localhost6
10.55.199.113 test test
### end of base hosts configuration ###
10.55.199.113 test4 test4
fe80::20c:29ff:fe18:687c test6 test6

Could anyone pls help me in this.

jpollard · 01-14-2013, 05:43 PM

I believe the problem is that you have conflicting IP numbers for the host.

It looks to me like both 10.55.199.113 and fe80::20c:29ff:fe18:687c are for the same machine. I'm basing this on the fact 10.55.199.113 are both test4 and test. Forward lookups would find the 10.55.199.113, but a reverse lookup will only find test as that is the first entry.

I think that forward and reverse lookups have to match. Now whether ssh recognizes multiple IP numbers and adds all of them to the known hosts entry I don't remember.

skimeer · 01-15-2013, 03:01 AM

Yes both 10.55.199.113 and fe80::20c:29ff:fe18:687c are same machine. I have no issues over Ipv4 for resolution. However with Ipv6 its not working though I have added it in /etc/hosts files.