Sendmail gives error: Deferred: Network is unreachable

[Nivedita Tawade]

Hi,

I have configured sendmail on hp 11.0 as foll.:

1. added entry for smtp server in /etc/hosts
2. added entry for the same as DS Macro ( Smart Relay Host ) in sendmail.cf
3. To avoid DNS , changed ???Dj$w.FOO.com??? to ???Dj$w.???
4. To make UNIX work look in only /etc/hosts file , in /etc/nsswitch.conf file , put line as:
Hosts files

When I try
sendmail -v ntawade@knightsindia.co.in

it shows error -
ntawade@knightsindia.co.in... Connecting to alps-bdc via relay...
ntawade@knightsindia.co.in... Deferred: Network is unreachable

I could not find /etc/mail/switch.conf and /etc/resolv.conf . Is the error b'cos of that ? Pls help.

Thanks

[John Palmer]

Hi,

It sounds as though sendmail can't 'talk' to your Smart Relay Host (alps-bdc) possibly due to a routing problem.

Can you ping alps-bdc?

Regards,
John

[Peter Scott · Accepted solution]

For sendmail to work correctly, it needs to be able to resolve the name of the SMTP server, and it needs to be able to reach it.

Make sure that you have DNS set up correctly and that you have a route configured to the subnet the SMTP server is on. If the servers are on the same subnet, then this won't be necessary.

Try running nslookup to make sure you can resolve the name of the SMTP server, if not make sure the IP address of the seerver is in your DNS or your hosts file. Once you can resolve the server name, make sure you can ping it, if not make sure you have a route to the target subnet by running netstat -rn if you don't have a route, then create one in /etc/rc.config.d/netconf and run /sbin/init.d/net start. If you do have a route and everything is resolvable, then you need to make sure there are no ports being blocked within your network - is there a firewall between you and the SMTP server.

Hope this all helps

Pete Scott

[Stefan Farrelly]

Its a simple network connection problem. The server knightsindia.co.in is either temporarily unavailable (it might be down) or you dont have a complete network connection to it (there and back). Try connecting to it manually;

telnet knightsindia.co.in 25

Does it come up with connect to .... ? If not something is wrong with your network. Can you ping knightsindia.co.in or do a successful traceroute to it ?

[Nick Wickens]

Have you setup the file /etc/rc.config.d/mailservs correctly ? I think that the man page for sendmail details this.

[Nivedita Tawade]

Hi,

You are right. I am not able to ping SMTP server. I have to see why its not happening.

Thanks
Nivedita

[Nivedita Tawade]

Hi,

Thanks to all of you..especially Peter for your help. The default gateway was not set up. After setting nsconf, sendmail started working.

Thanks again
Nivedita