PoC: New

2026-06-28T19:53:51Z

New

New page

The '''OS/400 DNS server''' can officially be configured via '''OpNav''' only. However, there are other ways…

OpNav is a component of ClientAccess for Windows, which is installed along with OS/400.

== Configuration ==
The DNS server of OS/400 V4R2 up to and including V4R5 is based on BIND 4.9.3 from the ISC. Therefore, the configuration directives from ISC apply immediately. At startup, the system looks for the main configuration file ''/QIBM/USERDATA/OS400/DNS/BOOT''. You can easily create this file yourself:

Dns DNS von OS/400 V4R2 bis einschliesslich V4R5 basiert auf BIND 4.9.3 vom ISC. Somit gelten auch die Konfigurationsdirektiven unmittelbar. Beim Start wird nach der Hauptkonfiguratiosndatei ''/QIBM/USERDATA/OS400/DNS/BOOT'' gesucht. Diese kann man bequem selbst erstellen:
edtf '/qibm/userdata/os400/dns/boot'

Example file content:
; Working Directory
directory /QIBM/USERDATA/OS400/DNS
; Root-DNS-File
cache . NAMED.ROOT
; Zone Statements
secondary myzone.com 192.168.1.11 db.myzone.com

''Edtf'' is very similar to ''seu'' in its operation . Alternatively, this file can be created elsewhere and uploaded to the appropriate location in ASCII mode via FTP.

It is recommended to import an up-to-date root zone file. This can be obtained, for example, from [https://www.internic.net/domain/named.root Internic], and transferred via FTP to ''qdns/qatocdnsrv.root'' as well as to ''/qibm/userdata/os400/dns/root.hint'', as specified in the corresponding directive.<ref>BIND cannot deal with a file in a library. It's unclear why there is a copy in a ''qsys.lib'' file.</ref>

The directory permissions must be adjusted before starting the DNS server:
strqsh cmd('chown qtcp /qibm/userdata/os400/dns')

Through the <code>chgdnsa</code> command, you can set ''autostart at TCP startup'' to ''*yes'', as well as a desired debug level, and finally issue <code>strtcpsvr *dns</code> to start the server.

Less encouraging is the fact that when testing this DNS as a secondary to BIND 9.10.3 running on Debian Linux, no secondary zones can be loaded. The primary server pushes the zones out via AXFR, but the slave on the AS/400 does not accept them. According to the AXFR job log, BIND expects more data bytes than it receives. A fix to this behavior is not known.

== Weblinks ==
* [http://www.cs.ait.ac.th/~on/O/oreilly/tcpip/dnsbind/ch04_03.htm Setting Up a BIND Configuration File], O'Reilly Books
* [https://www.redbooks.ibm.com/redbooks/pdfs/sg245147.pdf AS/400 TCP/IP Autoconfiguration: DNS and DHCP Support], IBM RedBooks

[[Category: Software Configuration Guide]]
[[Category: System Administration]]

Configuring the OS/400 DNS server without OpNav - Revision history

PoC: New