Two Mac addresses

[matthew robey]

Hello there,

OpenVMS V7.3-2
TCPIP V5.4 Eco 4
Decnet V (Over IP)

The nic has mac address of 00-02-A5-20-17-EB


the switch sees the mac address as AA0004000604


and a MC NCL SHO OSI TRANSPORT ALL gives


UID =
732992B9-84C7-11D9-862D-AA0004000604 (note the last 12 characters)


Any ideas why the switch doesn't see the address as 00-02 etc

[David B Sneddon · Accepted solution]

Matthew,

When you configure DECnet V you have the option
of using Phase IV addressing. I assume you selected
YES to that option. DECnet is changing the MAC
address of the NIC to match your Phase IV DECnet
address. If you don't *need* the Phase IV addressing
you can turn it off and a reboot should show the
00-02... address.

Regards
Dave

[matthew robey]

Thanks Dave,

I was sure that I had seen this type of mac address before, but couldn't put my finger on it.

Matt

[Robert Gezelter]

Matt,

Concur with Dave. A further note. The DECnet Phase IV-ism with the MAC address is one of the reasons that DECnet needed to be started before the IP stack or LAT.

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

[Antoniov.]

yes,
this is the reason of decnet can't support two address on same server.

Antonio Vigliotti

[Jan van den Ende]

this is the reason of decnet can't support two address on same server.


...with one VERY IMPORTANT exception!

With DECnet, you can have a _REAL_ cluster alias, which is an other DECnet address!

That stupid IP has something they dare call that, but it is just a single-network device alias, that can fail over provided _NO_ active connections.

A DECnet alias is valid SIMULTANIOUSLY over ALL servers, and PER application you dedine your outgoing ID to be the server or the alias.

Proost.

Have one on me.

Jan

[Wim Van den Wyngaert]

It is possible to have 2 decnet addresses but both will be used to reach the destination, t.i. they are considered to be connected on the same network.

If the network is not the same, it is still possible to fool decnet by keeping the correct line open via a permanent job. We once did that (decnetplus using nsp transport).

Wim