Re: Safe Passage SSH tunneling

From: Darren Tucker (dtucker_at_dodgy.net.au)
Date: 06/22/04 

Date: Tue, 22 Jun 2004 01:18:44 +0000 (UTC)

In article <e95a3792.0406211307.56b2bf05@posting.google.com>,
joe briggs <scotty@cm.math.uiuc.edu> wrote:
>I'm currently using Safe Passage to tunnel my traffic
>(http://vastrange.com)
>to my internal corporate SSH server running linux (serves as my VPN).
>
>The problem is that it only seems to work well with a linux server
>when my administrator runs Open SSH with the -4 option (sshd -4).
>What's up with OpenSSH and the -4 option??

If by "not work well" you mean "intermittent freezes" then you're
probably being bitten by broken DNSes that silently drop requests for
AAAA addresses (ie IPv6 DNS lookups). This causes sshd to hang while
it's waiting for a reply.

sshd -4 == no AAAA lookups == no silent drops == no intermittent hangs.

The details are in this thread:
http://marc.theaimsgroup.com/?l=openssh-unix-dev&m=108666563719196 

-- 
Darren Tucker (dtucker at zip.com.au)
GPG key 8FF4FA69 / D9A3 86E9 7EEE AF4B B2D4  37C9 C982 80C7 8FF4 FA69
    Good judgement comes with experience. Unfortunately, the experience
usually comes from bad judgement.