This should work... shouldn't it?

[Charles Holland]

Have two L2000 boxes (and other systems as well) which have 100MB interface cards. All are connected through a HP J3235A
"AdvancedStack Hub 8TXE".
The NIC cards in the two L boxes are described by ioscan as A5230A/B5509BA. In system "T" it is set at 100MB Half Duplex and Autonegotiaion on. On system "H" it is set at 100MB Half Duplex with Autonegotiation off.

I'v searched the forums and have tried the suggestions of "lanadmin -X 100FD" which the systems apparently accept. Shortly there after response times become longer and longer to make DB inquires from one machine to another. Until in frustration we issue the command "lanadmin -X 100HD" to set it back to half duplex, and slowly our response times decrease.

What has been suggested is that our hub is not capbable of doing full duplex and that we should just wait and try again when we switch it out with a switch.

All comments, suggestions are welcome with points be awarded accordingly. Thanks

[Pete Randall]

Charles,

If you've been setting both NICs to 100FD *AND* forcing the port in the hub to 100FD, it should work nicely. If you can't force the hub's port, then you should leave at 100HD.


Pete

[Uday_S_Ankolekar]

100 FD should work well with your NIC's but if your hub is not capable of handling Full duplex then you are stuck. Only other thing I can suggest you is, it's always better if you configure auto-neg off on NICs and as well in switch port.

-USA..

[Patrick Wallek]

I can't find anything that says definitively whether or not that hub support 100FD. It does sound as if that is your problem though. If things get bad with 100FD on your servers then leave it at 100HD.

I would agree that you should definitely try again if/when you get a switch. At the point be sure you set the switch ports at 100FD (Auto neg off) as well.

[Jeff Schussele]

Hi Charles,

I agree with Pete.
If you don't have the hub or switch port locked in to a specific duplex, you'll cause all kinds of collisions & retries which will appear to you as diminished throughput.
So if you want to run full duplex & you should, then the port has to be locked down to full duplex & you'll need to also lock the NIC to full duplex in it's appropriate /etc/rc.config.d/?????conf file.

Rgds,
Jeff

[Charles Holland]

Pete,
In the documentaion on the Hub there is nothing in the Installation and Referance Guide to indicate how to change between HD and FD. To install it, back in 1999 I believe, we simply pluged in the network cables from the NIC cards and turned it on. That was it.

[Steven E. Protter]

I don't understand why you are making the change.

But.

If you are going half duplex, you need to have everything, including hubs and switches set that way explicitly.

HP NIC's running 100 BaseT have known issues with Cisco and other switches set for auto negotiate.

SEP

[Geoff Wild]

The J3235A is Half Duplex only.

Set your servers to 100HD, auto-neg off.

Found a pdf here:
http://www.doors.ch/DOCS/HP/COMM/HUBS.PDF

Only the 12TX's are Full Duplex.

Rgds...Geoff

[Hai Nguyen_1]

Charles,

If all interconnected devices are capable of autonegotiate, leave it that way. Otherwise, if you want to force duplex/speed settings, you have to do the same on all interconnected devices.

Hai

[Zeev Schultz]

Pick a 8 port fd/hd/autosensing 100bt switch
for more convinient settings.Like here:
http://www.hp.com/rnd/pdfs/compact_switch_hub.pdf (ProCurve 408 j4097b)

Zeev

[Pete Randall]

Charles,

It sounds like the hub is un-configurable, then. In that case, set both NICs to 100HD until such time as you get a new switch and you'll have much better results.


Pete

[Bill Costigan]

Generally speaking hubs are always half duplex.
They are simple repeaters and do not have the buffering to handle full duplex. the hp 10/100 hubs have a single bridge between the 10 baseT ports and the 100 baseT ports that can buffer packets, but trafic that simply comes in 100 and goes out 100 has no buffering.

Switches on the other hand has buffering and can usually handle both half and full duplex ports.

As was suggested turn off auto-neg on the NICs and set them all for half duplex.