Re: full/half duplex problem


Casper H.S. Dik wrote:
cconnell_1@xxxxxxxxx writes:

The nortel gb switch side is fixed full duplex, you cant change it. You
can only change the flow control settings which dont make any
difference anyway. I changed the
adv_autoneg_cap to be on and now when I disable/enable the port it
comes up in full duplex on the solaris blade.

You can't have "fixed full duplex" in Gbit ethernet.

Autonegotiation is *required* for Gbit.

Now, it can be so that the Nortel switch will only autonegotiate
1000 FDX, but if it is configured not to autonegotiate it's not
a Gbit ethernet switch.

Boot solaris blade, link comes up as 1000 full duplex -- OK
Disable/enable a port on the nortel switch - link comes up as 1000 full
duplex -- OK
Both kstat report 2 as link_duplex

BUT

If you reboot the switch module 'after' the blade is up, the link
changes to half duplex mode, and when it comes all the way back up it
stays as half duplex (kstat reports 1)

So after the switch reboots, it goes to half-duplex mode? And what
does the switch think it is set at?

Make sure that you leave auto_neg_cap on but limit the advertised
capabilities to the one you want (full-duplex/1000mbit)

Casper
--
Expressed in this posting are my opinions. They are in no way related
to opinions held by my employer, Sun Microsystems.
Statements on Sun products included here are not gospel and may
be fiction rather than truth.


Hi,
The switch always thinks the link is full duplex as its fixed at full
duplex atter its rebooted so the output of /i/link is always the same.
This was for some reason directed by ibm to nortel to have

1 Gbps
Full Duplex
RX & Tx Flow Control
Auto Negotiate off

The server link comes up as half after its rebooted. We are trying to
change this so the nortel has auto.

.

Relevant Pages

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