topic Re: DNS and local file in Operating System - OpenVMS

DNS and local file

Wim Van den Wyngaert — Mon, 25 Jun 2007 10:02:22 GMT

We currently don't use DNS but a local file.

For non-vms nodes, we would like to enable DNS.

$ ucx set nam/serv=a.b.c.d/system/enable
$ ucx sho ho toto.srv.tata.titi.be
shows the ip info.
$ telnet toto.srv.tata.titi.be
also works

Are there any side effects for the current IP users ?

Wim

Re: DNS and local file

Volker Halle — Mon, 25 Jun 2007 10:10:49 GMT

Wim,

enabling the Name Resolver may have an effect on incoming IP connections as well. Some UCX services may try to look up the hostname based on the IP address. This may add an additional delay to the connection establishment phase. Especially if the DNS server pointed to by the UCX name resolver is flaky or cannot resolve the address to name lookup.

Volker.

Re: DNS and local file

Wim Van den Wyngaert — Mon, 25 Jun 2007 10:17:44 GMT

BTW : 7.3 with tcp 5.3 eco 2.

Wim

Re: DNS and local file

Wim Van den Wyngaert — Tue, 26 Jun 2007 04:05:44 GMT

So, no potential problems for outgoing stuff and for local stuff (between 2 cluster nodes) ?

Wim

Re: DNS and local file

Jess Goodman — Tue, 26 Jun 2007 10:28:10 GMT

Wim,

If by "For non-vms nodes, we would like to enable DNS" you really mean:

"So that the VMS nodes can use DNS to resolve names/IPs not in the local VMS host file"

Then the command you used will work fine. Any DNS lookup requests will first search the local file, and only if the name/IP was not resolved will the request then go to the DNS server you specified.

The only side effect you might see for a command that was previously used with just the local host file is with "UCX SHOW HOST". This will still dump out the local host file first, but then depending on how your DNS server is configured you may get a dump of its entire table, or if it doesn't allow that you might get the error message:

%UCX-W-NORECORD, Information not found

Re: DNS and local file

Wim Van den Wyngaert — Tue, 26 Jun 2007 10:36:10 GMT

Yep. Zone transfer was unsuccessful. So, no dump is given.

Wim

Re: DNS and local file

Wim Van den Wyngaert — Wed, 27 Jun 2007 08:22:03 GMT

During boot :

ucx start mail will go in hang for some time when DNS is enabled. If you disable it, everything goes fine.

Re: DNS and local file

Wim Van den Wyngaert — Wed, 27 Jun 2007 08:22:46 GMT

Oeps , too fast.

... when there is no network connection.

Wim