Change IP and DECnet address on Openvms

[geir_2]

Hi,

Is it difficult to change the IP and DECnet addresses on OpenVMS?

Geir

[Karl Rohwedder · Accepted solution]

Geir,

what is difficult :-) ?

DECnet Phase V: @SYS$MANAGER:NET$CONFIGURE
DECnet Phase IV: @SYS$MANAGER:NETCONFIG
TCPIP: @SYS$MANAGER:UCX$CONFIG or TCPIP$CONFIG

Beware to set SCSSYSTEMID correct.

Search in the OpenVMS forum, there are threads already covering this topic.

regards Kalle

[geir_2]

Hi,

Thanks :-)

[Volker Halle]

Geir,

note that if you want to retain the IP node name and only change the IP address, you would need to delete the IP node name from the local TCPIP host database first:

$ UCX SET NOHOST ip-node-name

Volker.

[Daniel Fernandez Illan]

Geir.
For me there are steps to modify IP and DECnet adresses:
1 - Modify SCS parameters (SCSNODE & SCSSYSTEMID)
on PARAMS.DAT (using SYSGEN) and MODPARAMS.DAT
2- Modify DECnet local name using NET$CONFIGURE (option 2)
3- Check new local name using DECNET_REGISTER
4- Modify routing values editing NET$ROUTING_STARTUP.NCL.
5- Modify ip values using TCPIP$CONFIG.
6- Reboot node

Saludos.
Daniel.

[Robert Gezelter]

geir,

Daniel is correct to remind you to reset SCSSYSTEMID (see the HELP text in SYSGEN for the formula to convert the DECnet node number to SCSSYSTEMID).

He is also correct to remind you to check the name resolution mechanisms to ensure that the machine is properly identifiable.

On the IP side, I tend to favor running the machine with both IP addresses for a day or so. Many sites run their DNS servers with non-trivial timeouts (e.g., hours or days). Often, the DNS servers are also administered by a different group, and arranging for entries to be purged/modified can be a problem).

For that reason, I recommend multihoming the IP connections, and doing the changeover in the following sequence:

- Add the new IP address as a second address.
- Verify that the machine is reachable using the new address
- Notify the network group that the machine has a changed address.
- Wait an extended time (e.g., days or weeks; depending on a MULTIPLE of the DNS lifespans -- you can get this information without the cooperation of the network group by using NSLOOKUP on the zone record for the zone).
- Remove the old address once all of the DNS servers are no longer holding out of date cache entries

The above minimizes the potential for user disruption.

I hope that the above is helpful.

- Bob Gezelter, http://www.rlgsc.com

[geir_2]

Hello,

Is it necessary to delete the IP node name from the local TCPIP host database first, since I want to use the same nodename??

1) IP
UCX SET NOHOST ip-node-name

2) DECnet IV
$ mc Sysgen
sysgen>

At end run config scripst/command.


Thnaks

[Volker Halle]

Geir,

if you use the same IP nodename again when defining the first interface, you provide an existing name and want a new IP address, but the same name already exists with the old address and therefore the name - address pair cannot be entered in the local TCPIP host database.

Volker.

[Colin Butcher]

See "Ask the Wizard" and the VMS FAQ.

This is useful background in the FAQ:
"MGMT9. How do I change the node name of an OpenVMS System?"

[Klaes-Göran Carlsson]

And if you have some applications installed which are dependent on the nodename... like Object Broker, DECEDI.... then you of cource have to change there as well... but thats obvious, isn't it?
/Klaes-Göran