SUMMARY: Full duplex tp ethernet mode for sun?

From: Detlev Habicht (
Date: Wed Jun 04 1997 - 04:18:48 CDT

Hi all,

i asked this question:

 We have just installed a Cisco Catalyst 3000 ethernet twisted pair switch
 in our Sun network.

 This switch has a full duplex mode for 100BaseT and 10BaseT connections.
 This is a new feature for me. The manual told, i can now drive
 twisted pair with 20 Mbps or 200 Mbps.

 Now my question: Which Suns can i drive in full duplex mode or what must
 i do to drive a Sun in full duplex mode?

Well, i don't tell something about my hosts. First i want to use a ULTRA 2
in full duplex mode. This is possible. (I have to check in the future, what
i can do with my other hosts. (Ultra 1, SS10, SS5))

I change my system to the same configuration, described in the mail from
"S. Varshney" <>:
  Hi here's a summary posted earlier, ie if you have the sunfast ethernet
  adapter on your SUN:

  ere is a doc in the answerbook for Ultra h/w setup describing the
  parameters to set for full duplex operation:

  1) Driver dependent config (/kernel/drv/hme.conf):
  -- ------ --------- ------ -----------------------
  adv_autoneg_cap = 0 adv_100fdx_cap = 1 adv_100hdx_cap = 0 adv_10fdx_cap = 0
  adv_10hdx_cap = 0;

  2) /etc/system config:
  -- ----------- -------
  * Begin hme - force 100BaseTX - Full Duplex Mode
  set hme:hme_adv_autoneg_cap=0
  set hme:hme_adv_100hdx_cap=0
  set hme:hme_adv_100fdx_cap=1
  * End hme

  3) ndd config setting:
  -- --- ------ --------
  ndd -set /dev/hme adv_autoneg_cap 0
  ndd -set /dev/hme adv_100hdx_cap 0
  ndd -set /dev/hme adv_100fdx_cap 1

  So far I have had no problems using Full Duplex 100BaseTX mode on my
  Ultra Creator 1 with Bay's 28115ADV 10/100 switch, agent software
  version 2.012.

  How to check what mode and speed a hme adpater is current running at:
  sunbay:/# ndd /dev/hme link_speed
  1 1 - 100MB/sec
  sunbay:/# ndd /dev/hme link_mode
  1 1 - Full Duplex Mode

  Note: When you do a 'netstat -i' you should notice that the collision
        count should be zero...

Well, i think, this works. I have a connection ( ;-) and have the
same results like S. Varshney. The Cisco configuration menu shows me
also full duplex mode (the Ultra is connect on port 21).

Port Type Link MDI/MDIX Speed Mode Duplex Enabled/Disabled
 20 10BaseT up MDIX 10 A-CT Half Enabled
 21 ISL TX up MDIX 100 A-CT Full Enabled

Another answer comes from Len Rose <len@NETSYS.COM>. I don't it test now,
but i think, it may be a good hint for more performance:

  You should set configuration in /etc/system (not /kernel/drv/hme.conf)
  See below problems..

  Sun's hme driver doesn't seem to negotiate f/d operation and most switches
  don't support it anyway.

  Add this to /etc/system

  # 100bb full duplex mode
  set hme:hme_adv_100fdx_cap = 1
  # force 100mb full duplex mode
  set hme:hme_adv_autoneg_cap = 0
  I recommend increasing tcp transmit & receive buffers from 8k to 64k
  for performance reasons.

  You can do this after booting by:
  ndd -set tcp_recv_hiwat 65536
  ndd -set tcp_xmit_hiwat 65536

  (I ended up creating an rc script to do this)

  I haven't discovered how to make the changes permanent, I did try
  modifying these variables in /etc/system but they didn't seem to work..

  set tcp:tcp_xmit_hiwat = 65536
  set tcp:tcp_recv_hiwat = 65536
  I also tried making the changes in /kernel/drv/tcp.conf and they didn't
  work either..

  name="tcp" parent="pseudo" instance=0

Some people write me, that they have trouble, running full-duplex mode
with Bay switches. And some people say auto-negotiate dont't work with
Sun interfaces. I can't test Bay, but auto-negotiate with ULTRA 2 and
Cisco Catalyst don't work here, too. So i have also to force it via the
settings in /etc/system.

And i think, the answer from Benjamin Cline <> is also

  It's my understanding that the only Sun ethernet adaptor that supports
  full-duplex mode is the hme fast ethernet adaptor, availble on some
  SPARC-Ultra models (Ultra1 "E" series, Ultra2) and as an SBus add-in card.

Thanx also to:

bismark@alta.Jpl.Nasa.Gov (Bismark Espinoza)
"Mark Baldwin" <>
Farzad Mansour <>
Chan Ling Ling <>
"Matthew Stier" <> (Craig L. Gruneberg)
Karl von Jena <>

bye and have a nice day!


 Detlev  | Institut fuer Mikroelektronische Systeme, Uni Hannover
 Habicht | D-30167 Hannover +49 511 7624992

This archive was generated by hypermail 2.1.2 : Fri Sep 28 2001 - 23:11:56 CDT