On Sat, May 4, 2013 at 4:37 PM, Andrei POPESCU <andreimpope...@gmail.com> wrote: > On Sb, 04 mai 13, 19:15:43, andrey.ry...@bilkent.edu.tr wrote: >> hi all! >> Some time ago i get next problem. >> Net connections start work by"by jerks". In case of ssh session it look >> like this: i can put my command in bash shell but some time (from 10 to 20 >> seconds) screen is frozen. After that: input and output of the session for >> some time work as usual. >> I have no idea how i can diagnose this problem. What i should check? > > DNS. As far as I remember there was quite recently a problem just like > yours discussed here on debian-users, you could search the archives (if > you haven't already).
Indeed, the sshd daemon is configured to do a reverse DNS query for each connection request. Since you're using local IP's and have no reverse DNS setup (I assume...) those queries time out. It's not really necessary to do a reverse DNS search to authenticate a client, since in an untrusted network, the DNS server could be compromised too (someone correct me if I'm wrong), and you'll do public key challenges or ask for a password anyway so you can safely disable this. You'll need to add "UseDNS no" on the server /etc/ssh/sshd_config to do it. Guido -- To UNSUBSCRIBE, email to debian-user-requ...@lists.debian.org with a subject of "unsubscribe". Trouble? Contact listmas...@lists.debian.org Archive: http://lists.debian.org/ca++dqumrcw4aktokqzodweokg+pbjz+dpwptmorhjlyeb8u...@mail.gmail.com
