autoneg problem

[James Ellis_1]

I have two servers here, both HPUX 11.0. Both set up exactly the same. Both have the patch bundle June 2000 (will soon install Sept 2001).
Ok, here is what I have a problem with.

Server1: autoneg CANNOT be set to "on". Its also running Half Duplex Mode, Speed is 100, card type is Fast Ethernet.

Server2: autoneg is on, speed and duplex mode is blank.

I want to set Server 1 autoneg to "on". But I cannot do so.

When running ioscan -funC lan:

Server1:
btlan3 claim interface
/dev/diag/lan0 /dev/etner0

Server2:
btlan3 claim interface
/dev/ether0

Also, when doing more hpbase100conf I get these:

Server1:
HP_BASE100_INTERFACE_NAME[0]=lan0
HP_BASE100_STATION_ADDRESS[0]=
HP_BASE100_SPEED[0]=100HD
HP_BASE100_DUPLEX[0]=

Server2:
lan0
0X0010837C124C
Auto_on
(blank)

Server1 has: PHNE_21217 and dependency PHNE_15612.

Server2 has: PHNE_20657 and dependency PHNE_15612.

Notice that Server2 has the older patch but still works!

Now, you noticed that Server2 has a station address while Server1 does not? I doubt this will make a difference, but maybe it does. I would like to get Server1 to have autoneg = "on".

Any help would appreciate. I realize I can set the station and duplex values via the lanadmin command, and would have to do a reboot for the new values to take effect.

Thanks,
Jim

[Darrell Allen]

Hi Jim,

I'm not an expert here but...

It's a good thing to get patches updated. That was to be my first question.

How are you trying to set autoneg on and what is the error you get?

lanadmin -X can be issued on the fly but I'd have things stopped and be on the console just in case. You should be able to issue "lanadmin -X auto_on PPA#".

As you note, /etc/rc.config.d/hpbase100conf is the config file for btlan3. That's where to make the changes effective every boot.

I don't believe you need to have the station address. I'm not sure what it's used for.

Now, let me encourage you to force the speed setting instead of using autoneg. Yes, autoneg often works but many times it doesn't. I've seen autoneg fail on multiple flavors of UNIX as well as NT. It results in a duplex setting mismatch between the server and switch which allows communication but throughput slows to a crawl under a load.

Whatever you choose, you need to be sure to set the server and switch to match.

Darrell

[Geno Church]

James,

You'll have to hard code the card to the speed and duplex setting. The reason autoneg doesn't work is the card only checks the speed and not the duplex. If autoneg is turned on then it will always be HD. If the servers are going to a switch, you'll have to hard code both the server and switch port to the same speed and duplex with autoneg turned off. Also if the cards are using the btlan3 driver then the config file hpgsc100conf file in /etc/rc.config.d needs to be configured. As far as the station(mac address) goes in the config file, it is not needed. It picks it up automatically, besides if you set it and 6 months later the card dies and you have to replace it, then the mac address changes too since there all unique, and you would have to update the config file with the new address, if you remember to do so. So in short, no statin address needed.

[Geno Church]

My mistake, btlan3 is the hpbase100conf file.

Here is a list for future reference..

driver /etc/rc.config.d/

btlan0 hpeisabtconf

btlan hpbtlanconf

btlan1 hpbasetconf

btlan3 hpbase100conf

btlan4 hpgsc100conf

btlan5 hppci100conf

btlan6 hpsppci100conf

[James Ellis_1]

Geno,
You replied "If autoneg = on, then it will always be HD".

This does not appear to be the case with my server. The two servers I have their setting like this:

autoneg=on,speed/duplex= blank
autoneg=off,sp=100,HD

I looked at the patches, and I noticed that I have the PHCO_21187 patch, on both servers.

One server that works has the lan cumulative patch PHNE_20657 but not its dependency PHNE_15612

The server that does not work has the cumulative patch PHNE_21217 but not its depencency patch PHNE_15612.

Maybe I should coordate with the DB users/adm, and see if I can change the settings. If not, just try installing PHNE_15612. Upon reading this patch, this does not indicate that this fixes the autoneg problem...

Thanks,
Jim

[Krishna Prasad]

We manually set ours to 100/Full duplex and things work fine. In our case we are running APA and use VPN's and this a requirement for our setup.

[Bill Hassell]

Let's see if I can explain this ina simple manner: Autonegotiation went through growing pains for 100BaseT and there are basically three ways to determine the speed/duplex settings (IEEE 802.3u). Before 1994, the N-way negotiation standard did not exist so Auto-sense (10 Mbit) and a parallel detection method must also be used. This involves Fast Link Pulses and a lot of details to make it all work.

However, successful auto-negotiation requires agreement on the methods and timing, plus LAN cables that are less than 35 meters or longer than 41 meters. Because auto-negotiation uses special pulses and detection windows, certain cable lengths may fail to negotiate and the standard says: if auto-negotiation fails, default to 1/2 duplex.

However, if the LAN card is at 1/2 duplex and the switch is at full, the result is a huge number of errors and in some switches, the port may be automatically disabled.

SO unless your machines are in a testing lab where cables and switches are swapped on a daily basis, it is simpler to select 100 full-duplex for BOTH sides. Note: if you set the computer side to 100FD but leave the switch to autonegotiate, the switch may fallback to 100HD which is no good. If the switch cannot be changed, try a much longer LAN cable to see if autonegotiation can be successful with a longer (or shorter) cable. As mentioned, the 'gray area' is 35-41 meters. And this can explain why two different machines negotiate differently--the LAN cables are different lengths.