How do I direct-connect GigaBit LAN cards server-to-server at hp-ux 11i?

[Stuart Abramson_2]

We are getting new servers (rp7410-s), a new GigaBit switch and new GigaBit LAN cards to put in all of our current servers.

But, the GigaBit switch isn't arriving yet.

Can I "direct-connect" two of our servers together on a GigaBit connection (Copper)? I mean can I run a GigaBit cable from one GigaBit LAN card on server A to a GigaBit LAN card on Server B and talk between them at 1000 BaseT speeds?

Do I need a "cross-over cable"? We heard at HP World that the GigaBit card/software is so smart that it can test the connection and "adjust" for direct connect and you don't need a cross-over cable?

This will be HP-UX 11i, with which we have no experience.

[Jeff Schussele]

Hi Stuart,

Yes, as far as I know, you'll need a crossover cable to directly connect 2 Gig-E copper (1000Base-T) systems.
With Gig-E fibre you'd just run Tx->Rx on the systems for direct connect.

HTH,
Jeff

[Michael Kelly_5]

Stuart,
you definitely can "direct-connect" two GigaBit cards using a crossover cable to link two servers together "back-to-back".
I have this exact setup to provide a fast NFS link between two servers.
Come to think of it, I'm not certain that it is a crossover cable, I just asked the network guys for a crossover cable and what they gave me worked, maybe the cards can adjust for direct connection.

The only other thing you need to be aware of is to make sure that the IP addresses of the cards are on a different subnet. You can't have two or more cards in the same server on the same subnet.

HTH,
Michael.

[Berlene Herren · Accepted solution]

According to GB documentation: When running 1000Base-T back-to-back at either 10 or 100 Mbps, you must use a crossover cable configuration. At 1000 Mbps, you can use either a crossover or straight-through cable.

Berlene

[Tim Sanko]

1. Crossover cable is necessary.

2. The GIG switch is really necessary, for long term.

3. Fibre is nice to "swap" connection type.

Tim