We have installed Red had enterprise linux 3. We have separated the services dns, mail and proxy in separate systems. We would like to have another mail server. How to link the second mail server with previous one.

mali

We would like to have another mail server. How to link the second mail server with previous one.
If with "link" you mean "also make available for use" then it's adding another DNS MX record,
elif with "link" you mean "replace" then it's modifying the existing DNS MX record,
else you better explain in detail what you want to achieve.

Yes we wanted to make available for use the other server in addition to the existing one. I have tried by adding another MX Reconrd in DNS forward zone file. But it was not working.

With kind regards,
C. Mahalingam

I have tried by adding another MX Reconrd in DNS forward zone file. But it was not working.
One of the distinct advantages of working with GNU/Linux is Software will provide you with the "right" information: cryptic, yet exact. Wetware usually is switched to fuzzy mode: it doesn't not return ordered, exact information unless explicitly instructed otherwise. Being analytical and methodical boosts efficiency when troubleshooting.
Try it, you'll like it.

- in which configuration files did you make changes?
- what steps did you take exactly?
- with what tools and how did you test changes?
- what where the exact errors returned?

we are using redhat enterprise linux ES 3

for this os /var/named is default directory for storing zone files

i have added these two lines for mail exchange records

10 MX mailserver1
20 MX mailserver2

after entering these two lines i have checked with the following commands

named-checkzone <domainname> <forward zone file>
after checking the system produced the following result

zone <domainname>/IN: loaded serial 2006081826
OK

it gives no error

after this I have restarted the service

service named restart

here too it doesn't give any errors.

every thing look like OK

but the problem is if i am sending mail to mailserver1 it works problerly but not if sent it for mailserver2

mali

but the problem is if i am sending mail to mailserver1 it works problerly
If you:
0) incremented the serial and
1) the changes got propagated then the result from a
2) remote "dig" should show both MX records in place. If these conditions are met then
3) bringing down the "10 MX" mailserver,
4) making sure the "20 MX" mailserver is up and running and
5) sending an email to any valid address in the domain should show the message is accepted on the "20 MX" mailserver by
6) checking the maillog.
Each step must be checked and in this order and the result must be OK to be able to proceed with the next step.

after the second mail server installation I did the following

1. incremented the serial no
2. verified the syntax with named-checkzone
3. named services were restarted by service named restart
4. dig <domainname> shows both MX records

but i haven't tested with bringing down the "10 MX" mail server and tested with second mail server.

I will do and let you know this during this week end.

Thanks for your guidance.
mali

Your bind config files may actually be chrooted in /var/named/chroot/. Check if this directory exists. If so then make your changes in /var/named/chroot/etc/named.conf and /var/named/chroot/var/named/