Now that we separated the domain OTHERDOMAIN.mycompany.com into a second zone of authority from the mycompany.com domain, the question is what configuration changes we need to make, if any, for the purposes of delivering mail. The answer to that question depends on whether AS1 remains the only mail server in the network or if a second mail server will handle the mail for users in
the OTHERDOMAIN.mycompany.com domain.
5.6.1 AS1 as the Only Mail Server in the Network
The two zones of authority: mycompany.com and
OTHERDOMAIN.mycompany.com are separated for the purposes of DNS only.
The DNS server on AS1 is authoritative over the mycompany.com domain and the DNS server on OTHERHOST is authoritative over the
OTHERDOMAIN.mycompany.com domain. All hosts on the three networks,
10.5.69.192, 10.5.62.0, and 10.1.1.0, have TCP/IP connectivity to each other and the mail administrator certainly may choose to have the AS1 mail server as the only mail server in the network. In other words, users in the
OTHERDOMAIN.mycompany.com can have their POP3 client configured to have
and it arrives on the user’s POP3 mailbox on AS1 as we explained in Chapter 3.2.3, “Configuring AS1 as a Mail Server” on page 44.
For the preceding example where AS1 remains the only mail server in the network, there is no need for any further DNS server configuration changes on the parent name server AS1 nor on the child name server OTHERHOST beyond what was already configured for Chapter 3.2.3, “Configuring AS1 as a Mail Server” on page 44. The users in the OTHERDOMAIN.mycompany.com can have their PC configured to use OTHERHOST’s IP address as its DNS server. The name server on
OTHERHOST resolves the mail server’s IP address, which is AS1’s IP address.
In conclusion, even with the OTHERDOMAIN domain’s zone of authority
delegated to the child server OTHERHOST, the mail configuration outlined in Chapter 3.2.3, “Configuring AS1 as a Mail Server” on page 44 is the only mail
configuration necessary if AS1 remains the only mail server for the network. All POP3 users need a POP3 directory entry on AS1 with their SMTP domain name equal to AS1.mycompany.com. Mail can be addressed to the user using either: [email protected]
or
Both of the previous "mail to:" addresses allow mail to be delivered to the AS1 mail server.
5.6.2 Otherhost as the Mail Server for Otherdomain.mycompany.com
If OTHERDOMAIN.mycompany.com has its own mail server, and assuming that,
for example, OTHERHOST is that mail server, we need to make configuration changes to OTHERHOST and also to the mail server AS1.
5.6.2.1 Mail Configuration on Otherhost Mail Server
The mail configuration required on OTHERHOST is similar to the mail configuration outlined in Chapter 3.2.3, “Configuring AS1 as a Mail Server” on page 44. 1. The POP3 user needs a user profile and POP3 directory entry on the
OTHERHOST AS/400 system. It is important when configuring the SMTP domain
name for each user to make it equal to
OTHERHOST.OTHERDOMAIN.mycompany.com. See Chapter 3.2.3.1,
“Configuring a POP3 User on AS1” on page 45 for details.
2. We need to update the DNS configuration on the OTHERHOST child name server. The following steps are similar to what was outlined in Chapter 3.2.3.3, “Configuring the Domain’s Mail Server in the DNS Server” on page 48. However, this time, we perform the following DNS configuration steps outlined on the child server OTHERHOST.
• Configure a wildcard MX entry. Start OTHERHOST’s DNS server configuration in Operations Navigator.
1. Double-click Primary Domains.
2. Right click on OTHERDOMAIN.mycompany.com. 3. Right click on Properties.
7. Click OK.
8. Enter the host name of the mail server:
OTHERHOST.OTHERDOMAIN.mycompany.com. (Use the fully-qualified
host and domain name. Also, do not forget the trailing dot after com.) 9. Click OK.
10.Click OK.
• Verify that the mail server is listed as a host in the primary domain file of
OTHERDOMAIN.mycompany.com. It is, in this case. We added OTHERHOST
as a new host in OTHERDOMAIN.mycompany.com earlier in this chapter. • Verify that the mail server is listed as a host in the 1.1.10.in-addr.arpa
primary domain file. It is; it was automatically added when we added
OTHERHOST as a new host earlier in this chapter.
• Close the DNS window to save the configuration. Or, if the DNS server is already active, click on the Update Server smart icon to reload the DNS configuration changes while the DNS server continues to be active. 3. Check the TCP/IP and SMTP Configuration on OTHERHOST.
We need to verify the TCP/IP domain information and SMTP attributes. These steps are similar to the steps outlined in Chapter 3.2.3.4, “Verifying the TCP/IP and SMTP Configuration on AS1” on page 50 except that this time, the steps are performed on OTHERHOST.
• Use the CFGTCP command, option 12 to verify that the Search First is
*LOCAL.
• On the same display, verify that the Internet address is 10.1.1.2, which is the IP address of the local AS/400 OTHERHOST itself. The SMTP server running on OTHERHOST first searches the local host table to determine where to deliver the mail and if it does not find what it needs in the local host table on the AS/400 system, it queries the DNS at IP address 10.1.1.2
(OTHERHOST).
• Use the CFGTCP command, option 10 (on OTHERHOST system) to make sure that the host OTHERHOST is listed, has an Internet address of 10.1.1.2, and has an entry with a host name of OTHERDOMAIN.mycompany.com (do not put a period at the end of com when using CFGTCP option 10).
• Use CFGTCP option 10 (on OTHERHOST system) to make sure that the host AS1 is listed with an IP address of 10.5.69.222 and has an entry with a host name of mycompany.com.
• Use the CHGSMTPA command followed by F4 (to prompt) and page down once to check on the Mail Router and Firewall parameters. Mail Router should be equal to *NONE. The Firewall parameter should be set to *NO. 4. Add host name to the AS1 system’s local host table.
• On the AS1 system, issue CFGTCP option 10. Make sure the host OTHERHOST
is listed with an Internet address of 10.1.1.2 and has an entry with a host name of OTHERDOMAIN.mycompany.com.
5. Make sure that SMTP, POP, and QMSF jobs are active on both mail servers
OTHERHOST and AS1.
• Check the status of the SMTP server jobs, the POP server jobs, and the QMSF job or jobs. All jobs should be running under the QSYSWRK subsystem. Then use the WRKACTJOB SBS(QSYSWRK) command to view all active jobs in the QSYSWRK subsystem. You may have to page down several times to find the jobs we are looking for.
• The SMTP server is active if the following four jobs are active:
QTSMTPCLNT
QTSMTPSRVR
If these jobs are not active, you can start the SMTP server with the command:
STRTCPSVR *SMTP.
If the previous jobs are active and you made changes to CFGTCP option 10, option 12, or with the CHGSMTPA command, you must end and start the SMTP applications for the changes to take effect.
• The POP server is active if at least one job is active with the name QTPOPxxxxx, where xxxxx is any number. For example:
QTPOP00595 QTPOP00597 QTPOP00637 QTPOP00653
If at least one QTPOPxxxxx is not active, then start the POP server with the command:
STRTCPSVR *POP.
• Make sure at least one QMSF job is active under the QSYSWRK subsystem. The job name is QMSF. If a QMSF job is not active, then start one with the command:
STRMSF.
Starting the DNS server on OTHERHOST:
• If the DNS server is not started on OTHERHOST, the following AS/400 command will start it:
STRTCPSVR *DNS
• Once the DNS server is active, a job named QTOBDNS starts in the QSYSWRK subsystem. Its job log should be the first place the DNS
administrator looks if there is a problem. The job runs under the user profile QTCP. If the QTOBDNS job has ended, use the WRKSPLF QTCP command and then F18 to go to the bottom of the list of job logs. This should help you locate the QTOBDNS spooled job log.
As a child name server queries a parent name server (or vice versa) to get responses for queries that it is not authorized for, it caches the response. Thus, if the child name server is queried for the same information again, the name server will give the answer out of its cache instead of querying the parent server again. However, if the child server is stopped and started, it clears its cache. Therefore, it is beneficial to try to minimize the number of times the name server is stopped and started once it is in production. If configuration changes need to be made to the name server while it is active, the
recommended method is to use Operations Navigator and the Update Server TIP