More on Masquerading

[Ow Mun Heng]

On Sun, 2004-08-15 at 08:59, Harry Putnam wrote:
> One of these *mc files cures my bounce problem.  The one with the
> Masquerading stuff in it.
> 
> >From another thread I've learned that masquerading doesn't work as I
> thought it did but for years now I've been masquerading what ever
> machines I have at home as `newsguy.com'.  I thought I'd learned a way
> of using the `genericstable' to do something similar and not need to
> masquerade.
What exactly does genericstable do? (Sorry, writing this mail off-line)

> 
> My assumption was that the `Smart_host' at the other end of my
> sendmails outgoing activity required a resolvable host as source IP to
> avoid bouncing.  I thought by setting some genericstable vars I could
> make it appear to be a resolvable host name.
But it isn't right? newsguy.com isn't a valid Domain Name is it??
I'm not sure if your solution is a viable solution to my problem.

My Problem.

@work = mails must be sent out using the corp exhange server (smart host
feature _must_ be implemented via sendmail.mc)

@home = mails are sent out w/o using smart host. Meaning, I have to
actively re-compile sendmail.mc each time between office and home to
send out emails. Cause @home, mails gets relayed directly to the
receipient's MX. 

> It is not an internet FQDN, just my own made up domain for my local
> lan.  Therefore will never be resovable by dns lookups.
Just as I thought. And what/how does this affect mail sending?

> 
> My attempt at using generics tables consisted of adding:
> (see sendmail2.mc below for the full settings)
> 
>   FEATURE(`genericstable')dnl
>   FEATURE(`generics_entire_domain')dnl
> 
> And to /etc/mail/genericstable:
>    reader               reader at newsguy.com
What does this achieve?  I don't see a genericstable in my
 /etc/mail/ directory

> Building the hash and restarting sendmail.
> 
> With that in place I get these kind of errors:
> (wrapped for mail).  They happen too quickly to be coming from the
> smart_host so its my sendmail process rejecting it.
> 
> >From /var/log/messages
> 
> Aug 14 19:31:34 reader sendmail[12324]: i7F0VTsA012322:
> to=<reader at jtan.com>, ctladdr=<reader at reader.local.net0> (500/500),
> delay=00:00:04, xdelay=00:00:04, mailer=relay, pri=120355,
> relay=smtp.newsguy.com. [129.250.170.69], dsn=5.6.0, stat=Data format
> error

What's data format error? And I see that your relay is =
smtp.newsguy.com, which resolves to your Inet Public IP.

For my case, it gets relayed to the localhost (127.0.0.1)'s smtp. which
then hands it over to sendmail to contact the MX.


What I want to know is, is there a way to say that I want mails to be
sent out 1st using the Direct approach, if it fails then fall back to
the smart host.

Something like /etc/host.conf

user$ cat host.conf 
order hosts,bind

pseudo code :
if [check if it's a local address ]; then
	pass to local sendmail
elif [check if we can send direct to MX ]
	pass to sendmail for direct MX
else # when all else fails
       pass to smart host for relay


	
       



-- 
Ow Mun Heng
Fedora GNU/Linux Core 2 on D600 1.4Ghz CPU kernel
2.6.7-2.jul1-interactive 
Neuromancer 15:00:10 up 24 min, 5 users, load average: 0.42, 0.40, 0.36