Re: HP-UX 11.0 ftp doesn't work with any other system

From: Rick Jones (foo_at_bar.baz.invalid)
Date: 03/23/05 

Date: Wed, 23 Mar 2005 18:58:36 GMT

Alan D Johnson <adjtech@hvc.rr.com> wrote:

[ my previous stuff trimmed since it was not necessary for the
  discussion and trimming is good form ]

> Just a note from the "sidelines"... we have consistently found that
> with HP systems and Cisco gear that they normally don't talk
> together nicely in AUTO, especially if you set it in
> /etc/rc.config.d/hp(laninterface) and the switch/router port is hard
> coded. The behaviour that he is describing seems very familiar and
> has always been corrected by hardcoding both ports ( the switch and
> the lan interface ) to 100FD.

I may have misinterpreted what was written but, having one side
hardcoded and the other in AUTO is a configuration (aka operator)
error. In such cases, the fault dear friends lies not in our NICs but
in ourselves :)

How Autoneg is supposed to work:

When both sides of the link are set to autoneg, they will "negotiate"
the duplex setting and select full duplex if both sides can do
full-duplex.

If one side is hardcoded and not using autoneg, the autoneg process
will "fail" and the side trying to autoneg is required by spec to use
half-duplex mode.

If one side is using half-duplex, and the other is using full-duplex,
sorrow and woe is the usual result.

So, the following table shows what will happen given various settings
on each side:

                 Auto Half Full

   Auto Happiness Lucky Sorrow

   Half Lucky Happiness Sorrow

   Full Sorrow Sorrow Happiness

Happiness means that there is a good shot of everything going well.
Lucky means that things will likely go well, but not because you did
anything correctly :) Sorrow means that there _will_ be a duplex
mis-match.

When there is a duplex mismatch, on the side running half-duplex you
will see various errors and probably a number of late collisions. On
the side running full-duplex you will see things like FCS errors.
Note that those errors are not necessarily conclusive, they are simply
indicators. 

-- 
The glass is neither half-empty nor half-full. The glass has a leak.
The real question is "Can it be patched?"
these opinions are mine, all mine; HP might not want them anyway... :)
feel free to post, OR email to raj in cup.hp.com  but NOT BOTH...

Relevant Pages

  • Re: SunRay 2FS MTU
    ... That is the way autoneg is supposed to work - hardcoding causes ... is required by the spec to use half-duplex on the presumtion it is ... configured with half duplex. ... the duplex setting and select full-duplex if both sides can do ...
    (comp.sys.sun.admin)
  • Re: Mac OS X NAT/related TCP issue?
    ... Where are you running tcpdump? ... You said that the link was half-duplex and that it was supposed to be. ... When both sides of the link are set to autoneg, ... the duplex setting and select full duplex if both sides can do ...
    (comp.sys.mac.system)
  • Re: Mac OS X NAT/related TCP issue?
    ... Where are you running tcpdump? ... You said that the link was half-duplex and that it was supposed to be. ... When both sides of the link are set to autoneg, ... the duplex setting and select full duplex if both sides can do ...
    (comp.sys.mac.system)
  • Re: 100Mb lan tops out at 1.2Mb ?
    ... make sure there isn't a duplex mismatch between your hosts ... When both sides of the link are set to autoneg, ... If one side is using half-duplex, and the other is using full-duplex, ...
    (comp.os.linux.networking)
  • Re: NIC dropping packets
    ... clients on the local LAN segment. ... Please say you aren't hardcoding NIC duplex settings. ... When both sides of the link are set to autoneg, ... the duplex setting and select full-duplex if both sides can do ...
    (comp.sys.hp.hpux)