ssh, xinetd.d/ssh, bash login, IPv6 misconfiguration: huh?!

[Bill Eccles]

All,

OK, I know this is a trivial thing, but it bothers me, so it should bother you. (We’re all as anal as I am, aren’t we?!)

When I logged into a Jaguar machine, server or not, it always responded with a… well, button my… um, buttons!

Sorry for the interruption. I’ll explain later. Anyway, Jaguar machines responded with this:

Last login: Fri Jan 30 21:23:29 2004 from cube.mydomain.n
Welcome to Darwin!
[imacg4:~] admin%

Problem is, after upgrading to 10.3, this became:

Last login: Fri Jan 30 21:23:29 2004 from 192.168.0.3
Welcome to Darwin!
[imacg4:~] admin%

Funny thing is, I just fixed that problem! Unintentionally, of course, but it’s fixed, nonetheless. Here’s the rundown on that:

I got tired of seeing “sshd[1600]: reverse mapping checking getaddrinfo for imacg4.mydomain.net failed” in /var/log/system.log, so I went looking for info. I found a Japanese site (“Living with MacOS X,” I think) that told me, mostly because all the important bits were in a non-Japanese character set, that the file /etc/xinetd.d/ssh has a line in it that looks like this

        flags           = REUSE IPv6

and needs to look like this

        flags           = REUSE

resulting in a file that looks like this

service ssh
{
        disable = no
        socket_type     = stream
        wait            = no
        user            = root
        server          = /usr/libexec/sshd-keygen-wrapper
        server_args     = -i
        groups          = yes
        flags           = REUSE
#       flags           = REUSE IPv6
        session_create  = yes
}

just to be safe.

Indeed, upon changing the file and doing a kill -HUP on the xinetd process, the POSSIBLE BREAKIN ATTEMPT messages quit.

And, as I just discovered while getting the clues together for this posting (which is where I interrupted myself), the bash login now reports the last host logged in from (sorry, 11th grade grammar teacher) semi-correctly! It truncates the length of the line, I think, but reports enough back that I can now read where I logged in from last.

I know I’m not using IPv6. It’s disabled on all my machines as nothing I have here is compatible, I think. But what’s going on here that causes this?

Thanks for any clues, and I hope this helps someone else with a pucker factor similar to mine.

Bill

[Author]

Posts