Setting ewa0_mode while running OpenVMS

[Robert Atkinson]

My 2-penny worth......

I've been through a number of DR tests using various DE500 and DE602 cards, and generally found problems when trying to use AUTO on either end. We always set both ends to FastFD to ensure no problems.

After upgrading to Gig cards, I tried the same, but it wouldn't work. After chatting with the engineers and doing some tests, we're now happy that Gig cards should always be set to AUTO for both ends.

Rob.

[Jon Pinkley]

Both the switch and the embedded NIC are 1Gbps capable.

Autonegotiation should work, and is always recommended for 1Gbps devices.

Yes, there were problems with early switches and NICs that interpreted the autonegotiation specs differently, but the whole discussion about 10/100 devices has no bearing on this discussion.

The switch should be set to Auto, and your problems should go away. Jim's note about autonegotiation only happening at boot (init?) time is news to me, but we generally don't disconnect the cables, so I have no first hand knowledge concerning whether or not autonegotiation works after boot. I would have expected it to work if the cable was unplugged and reconnected.

[Jim_McKinney]

Some systems can/do autonegotiate every time a cable is unplugged and then plugged. However, to the best of my knowledge, VMS does not do so. My understanding is that the autonegotiation occurs when the system is initialized and then again when VMS boots and not again after that. I don't currently have the means to test/prove whether this is true.

[Richard Stockdale]

set device ewa/full/noauto - you have to turn off auto-negotiation otherwise it will just auto-negotiate again and get the same result (100 mbit half-duplex).

Note that setting the device to what is already set does not result in redoing auto-negotiation (so set dev/full is setting it to the same setting, i.e., enabling full-duplex and having auto-negotiation enabled).

Note that setting the device to anything different from what is set causes the device to be reset (if necessary) and new settings applied. You can reset the device by doing LANCP UPDATE DEVICE/RESET, but that is never necessary to cause new settings to be applied. You can reset the device to cause auto-negotiation to be redone.

Note that any link bounce (of sufficient duration) causes auto-negotiation to be redone. So unplugging and plugging in the cable again causes auto-negotiation to be redone.

Note the most modern devices do auto-negotiation in hardware without driver interaction, with a few exceptions, like the DEGXA-SA (or any fiber variants of Broadcom 570x devices).