%
%
&" #"! !$! #
depending on the interface to which the spect is connected to.
3. 4. Problems of Point–to–Point Connection to the O2
Both link partners of a Fast Ethernet Connection exchange their abilities (10 or 100 MBit
and Half or Full Duplex) after power up and without software interaction. They decide
then for the fastest common possibility. This procedure is called Autonegotiation re-
spectively Parallel Detection.
The main interface of the O2 is only able to operate in Half Duplex like an Hub. The se-
condary interface is ready for Full Duplex but there is no software support for this on O2.
The CU09 is able to run Half and Full Duplex.
This situation leads to an improper mode decision and to a Full Duplex link at the secon-
dary interface which can’t work.
To ensure an Half Duplex decision, the Full Duplex mode is switched off on CU09/10 by
software (Prom version 97/06/11 and Unix version 97/05/01 in
xwin–nmr2.0). This de-
creases the performance by at least 10 % and leads to collisions.
Furthermore, the point–to–point connection with O2 causes errors during the boot se-
quence.
This problem can be solved by connecting the O2 to the CU09/10 via an Hub or by con-
necting the CU09 to the main interface of the O2 (which behaves like an Hub).
Workaround
Swap logically both ethernet devices of the O2. That means, connect the
spect to ether-
net controller
ec0 on the motherboard of the O2. This can easy be carried out by modify-
ing the file netif.options.
Type on O2 as superuser:
vi /etc/config/netif.options
This file contains the 2 parameter entries of if1name=ec0 and if2name=ec1. Swap the
values of both parameters to:
if1name=ec1
if2name=ec0
Type:
:wq
init5
When the O2 is shut down swap also the connections, first connection between spect
and motherboard and the second between the general net and the additional interface and
reboot the O2 and than the
spect.
3. 5. Handling
3. 5. 1. Ifconfig down/up Procedure
A network subsystem can be made passive by ifconfig down and re–initialized by
ifconfig up. These commands trigger off the following actions:
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