We had this problem start yesterday.
We are running DU 3.2c on a 2100. Our DNS server is on an NT network.
People telneting/FTPing are from W95 machines on the NT network.
When someone would telnet either it would take a about a minute for the
login
prompt to come up or would never come up. FTP would come back as call
blocked.
The only people that could login were those who were specifically
defined
in the /etc/hosts. Since I'm using TCPwrappers, it was trying to do a
reverse
DNS on telnet logins (which is where I believe the hangup was from).
Once I removed the DNS entries from my /etc/resolv.conf, then the logins
were
fine (tcpwrappers was not compiled in Paranoid mode).
Here's the problem.
If I disable the tcpwrappers, however, I'm still getting telnet hanging
on logins, if I rename my resolv.conf file (disabling the DNS), the
logins
work fine, except now we can't send email (can't resolve the addresses).
What is causing telnet to do a reverse DNS and is there any way to stop
it
but still allow dns service for our email system (sendmail/mailx), aside
from
defining each IP address in the /etc/hosts file for all users.
George Gallen
ggallen_at_slackinc.com
Received on Fri Jun 04 1999 - 14:26:57 NZST