SUMMARY: Full duplex tp ethernet mode for sun?

Detlev Habicht (habicht@ims.uni-hannover.de)
Wed, 04 Jun 1997 11:18:48 +0200

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" <varshney@pacbell.net>:

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 m 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
tcp_xmit_hiwat=65536
tcp_recv_hiwat=65536

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 <benji@hnt.com> is also
true:

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" <baldma@hotmail.com>
Farzad Mansour <zod@home.net>
Chan Ling Ling <llchan@kdupg.edu.my>
"Matthew Stier" <mstier@hotmail.com>
clg@csph.psu.edu (Craig L. Gruneberg)
Karl von Jena <kvj@ix.netcom.com>

bye and have a nice day!

Detlev

-- 
 Detlev  | Institut fuer Mikroelektronische Systeme, Uni Hannover
 Habicht | D-30167 Hannover +49 511 7624992 habicht@ims.uni-hannover.de