Jack LaPlante said:
I'm setting up my nifty new dedicated web server with a firewall
like this: (I'm on RH9, the rpms look like the latest avail )
iptables -A INPUT -i lo -j ACCEPT
iptables -A INPUT -m multiport -p tcp --dport www,ssh,sftp,smtp,10000 \
iptables -A INPUT -j LOG -m limit
iptables -A INPUT -j REJECT
(an o'reilly setup from the linux security cookbook)
Now, when I log in via SSH or SFTP, there is a 30 second pause while my
password authorizes. It used to take a second or two. Flush the rules
and the login is up to speed again.
You don't allow inbound 53/udp, so your machine can't use DNS. By default,
sshd looks up the name of the connecting machine, and it looks like the
DNS lookup takes 30 seconds to time out.
I want to force my clients to use SFTP for all their file transfers but
the delay is going to be annoying.
Any suggestions to speed up my logins?
iptables -A INPUT --source $DNS_SERVER_IP_HERE -p udp --sport 53 -j ACCEPT
Assuming I got the syntax right, do that once for each DNS server you have.