Please help with sendmail problem

[RegrettableError at netscape.net (Bill Horne)]

"Jerry Feldman" <gaf at blu.org> wrote:

>You've got one problem here because union.ne.mediaone.net is a valid 
>mediaone host name. I strongly suggest that you name the hosts on your 
>internal net with a different domain, such as horne.net or something.
>Your sendmail.cw file is used for host forwarding.

Is that the sendmail.cf file, or a different one? Sorry if this is
obvious, but sendmail's not my area of expertise.
                      ^

>Checkout  http://www.sendmail.org/ for tips and faqs. 

Will do. (But see below)

>Bill Horne wrote:
>> Thanks for reading this: I'm having a problem with sendmail and need help.
>> 
>> I've got an entry in my /etc/hosts file for a machine on my home network, e.g
>> .,
>> 
>> 10.50.50.72   union.ne.mediaone.net
>> 
>> Also, in the /etc/hosts.conf file, the entry is "order hosts,bind".
>> 
>> However, sendmail, when trying to deliver mail to a user on union.ne.mediaone
>> .net, is doing a dns lookup *before* checking the hosts file, and is obtaining
>> an incorrect address that has not yet aged off mediaone's nameservers.
>> 
>> How do I force sendmail to check the /etc/hosts file first?
>> 
>> TIA.
>> 
>> Bill Horne

I should apologize for not giving more details: the objective here is to
set up a hot-swappable machine, which can be plugged into the cable
modem and assume its duties without reconfiguration. To that end, it has
been set up with DHCP so that it'll work with the cable modem if I need
to connect it directly, and when the Linux box is in between it and the
modem, Linux uses a "fixed-address" DHCP parameter to lock the "union"
machine to a known IP on my detached network. The "union" box has
software on it which requires a domain name and can't get it from DHCP,
so using a "phantom" domain isn't my first choice.

For that reason, I'd like to keep the "union.ne.mediaone.net" domain
name in the box if possible: I'd like the Linux router/firewall to use
the detached address when it's on line, but to have the "union" machine
revert to "dumb wintel" mode if I need to plug it into the modem
directly.

We all know crashes happen at the worst times: for me, they're always
when I don't have two brain cells to rub together and my wife is in need
of the net. Ergo, I want hot swap capability, where moving a patch cable
and a reboot is all that's needed to get the machine going.

If sendmail is hard-coded to do a DNS lookup, I'll use a different MTA,
but I want to solve this problem instead of going through another MTA's
learning curve. So, to restate: how do I force sendmail to check (and
believe) the "hosts" file instead of doing a DNS lookup?

Bill