The Internet Agent Displays a 450 MX Record Lookup Failure

Problem:  The Internet Agent has requested a lookup from the Domain Name Server and did not get a response.

Action:  Check the resolv.cfg file for correct configuration.

The resolv.cfg file should be in the following format:

domain your_domain_name  
nameserver ip_address
nameserver ip_address
nameserver ip_address

The domain name is first, followed by up to three nameserver IP addresses. The following is a sample resolv.cfg file:

domain sgunix.org  
nameserver 172.16.5.18

Possible Cause:  The IP address to your DNS has changed.

Action:   Update the resolv.cfg file.

Possible Cause:  TCP/IP is configured incorrectly.

Possible Cause:  There is a problem with your network interface card.

Possible Cause:  There is a problem with your network cabling.

Possible Cause:  The DNS server is down.

Possible Cause:  IP filtering has been added to the routers so the Internet Agent cannot see the DNS server.

Action:  Ping the nameserver IP address to see if it is reachable from the gateway station.

Action:  Ping the LAN segment router IP address.

Action:  Make sure the named Internet Agent program is running on the nameserver server.

Possible Cause:  Outbound ports are disabled. TCP/IP can use port 1024 through 2099 or some other range of outbound ports for sending.

Action:  Check with your Internet service provider for the outbound ports it uses.