IP6tables and sendmail

[Gregory P. Ennis]

Everyone,

I am putting together a new internal e-mail server using FC3 to replace a slower RH8 
server that has been working perfectly except for speed.  I am having difficulty 
getting sendmail to communicate to our relay that is also a RH 8 unit.

The FC3 unit does not appear to be able to send data to the RH 8 system.  The maillog 
file is receiving:

Connection refused by Rh8.domain.com

Interestingly I can telnet Rh8.domain.com 25 from the new FC3 machine and get right 
to sendmail.

In trying to tinker with iptables, hosts.allow, and the hosts.deny files on both 
systems I have not been able to make any headway.  When I used ifconfig on the FC3 
unit I noticed th6 and IP4 protocols.

eth0      Link encap:Ethernet  HWaddr 00:11:5B:55:75:2C
           inet addr:10.0.0.131  Bcast:10.0.0.255  Mask:255.255.255.0
           inet6 addr: fe80::211:5bff:fe55:752c/64 Scope:Link
           UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
           RX packets:33180 errors:0 dropped:0 overruns:0 frame:0
           TX packets:30041 errors:0 dropped:0 overruns:0 carrier:0
           collisions:0 txqueuelen:1000
           RX bytes:3181553 (3.0 MiB)  TX bytes:2684147 (2.5 MiB)

When I checked sendmail using lsof I found an entry for ip6 but not for ip4. I recked 
the sendmail.mc file and deactivated :

DAEMON_OPTIONS(`Name=MTA-v4, Family=inet, Name=MTA-v6, Family=inet6')adnl

After doing a restart to sendmail I did another lsof -i and found that it was 
listening using ip4, but I was still receiving maillog messages as being refused by 
the RH8.domain.com system.  The RH8 network card does not support ip6.

When I found the ip4/ip6 issue I thought I had the problem solved, but there were no 
changes in the symptons.  I am also having a problem with ntp and am wondering if it 
is related to the same issue as with sendmail.  Are there conflicts in using both ip4 
and ip6 protocols?

Any ideas?

Thanks ahead of time!

Greg Ennis