red lion 308FX2, Руководство пользователя

Страница: 36 / 40

3-24 N-Tron® Series 300 TX/FX Models User Guide
Operation and Maintenance Revised 2015-12-04
Ports Commands
By default, the RJ45 ports are auto-sensing for speed, duplexing, and crossover or straight through wiring. When
you select ANY ‘forced’ option, the auto-sensing for that port is disabled for all three parameters and the ‘remain-
ing’ (unforced) options are set to 100 Mbits, Full Duplex, and straight through cabling. For example, if you select
speed10 for port 2, then port 2 will be: speed10, full duplex, and straight through wiring. If you need ‘half duplex’
also on port 2, you will have to select it also as auto-sensing will be disabled for port 2 after you forced speed10.
The FX ports are always 100 Mb, and Full Duplex.
Note: In a LAN it is best to set ALL devices at autonegotiate, or to set ALL devices to the same
mode (speed/duplex).
If one end of a link is set to forced speed/duplex, but the other end is not forced, problems can be created.
On the 308FX2, 309, 316, or 317, it is possible to autonegotiate, or force to any of 4 modes: 100 full, 100 half, 10
full, or 10 half.
If you force one unit into 10/full, and leave another in autonegotiate (the default), the unit in autonegotiation does
not go into 10 full mode. It goes into 10 half. It gets no autonegotiation response. It easily senses speed passively,
but has no way to sense duplex mode and so uses the “safest” duplex mode - half. This is in accordance with the
IEEE specification. Thus, you have one unit at 10 full and the other at 10 half - basically functional but not ideal.
The unit at 10 full transmits without checking for busy and you get more data collisions. Also, the 10/full unit does
not back off or retransmit based on the collision domain.
The same problem results with one unit forced to 100/full and the other autonegotiating. The autonegotiating unit
goes into 100/half mode.
The available “ports’ commands are listed and described in Table 16 .
Table 16.
Ports Commands
Command Description Next Prompt
info Get information on port parameters
enabling Enable or disable each port
negotiate Select autonegotiate or not for each port Enter ports that are to autonegotiate:
speed10 Force 10 Mb speed for each port Enter forced 10 Mb ports:
speed100 Force 100 Mb speed for each port Enter forced 100 Mb ports:
half Force half duplex mode for each port Enter forced Half duplex ports:
full Force full duplex mode for each port Enter forced Full Duplex ports:
crossover Force crossover connection for each port Enter forced crossover ports:
Each time a forced port function is selected (speed, duplex, or crossover) the ports entered next are the complete
new set of ports for that function. For example, if you enter ‘speed10’, then respond with only <enter> (no ports) to
the prompt “
Enter forced 10 Mb ports :”, then no ports in the switch will be forced to 10 Mb, regardless of prior his-
tory.