During network tests with mismatched duplex settings we found the impact to bevery significant. 1.5Mbps (mismatched) vs. 60 or more Mbps (matched).
Following is some info on setting the duplex mode... http://support.ap.dell.com/docs/network/063my/linux.htm Optional parameters for the driver can be supplied as command line arguments to the insmod command. Commonly, these options are specified in a module configuration file: "/etc/modules.conf" or "/etc/conf.modules." See the Linux man page for more details on the module configuration file. These parameters take the form: <parameter>=value[,value,...] where the multiple values for the same parameter are for multiple NICs installed in the system. All the parameters are listed below. line_speed Selects the line speed of the link. This parameter is used together with full_duplex to select the speed and duplex setting of the link. The valid values are: 0 - Auto-negotiate (default) 10 -10 Mbps 100 -100 Mbps Note that selecting 1000 Mbps manually is invalid. 1000 Mbps can only be achieved through autonegotiation. full_duplex Selects the duplexity of the link. This parameter is used together with line_speed to select the speed and duplex setting of the link. Note that this parameter is ignored if line_speed is 0. The valid values are: 0 half duplex 1 full duplex (default) rx_flow_control Enables or disables receiving flow control (pause) frames. This parameter is used together with auto_flow_control. The valid values are: 0 pause receive disabled (default) 1 pause receive enabled if auto_flow_control is set to 0, or pause receive advertised if auto_flow_control is set to 1 tx_flow_control Enables or disables transmitting flow control (pause) frames. This parameter is used together with auto_flow_control. The valid values are: 0 pause transmit disabled (default) 1 pause transmit enabled if auto_flow_control is set to 0, or pause transmit advertised if auto_flow_control is set to 1 auto_flow_control Enables or disables auto-negotiation of flow control. This parameter is used together with rx_flow_control and TX_flow_control to determine the advertised flow control capability. The valid values are: 0 flow control auto-negotiation disabled (default) 1 flow control auto-negotiation enabled with capability specified in rx_flow_control and TX_flow_control (only valid if line_speed is set to 0) mtu Enables jumbo frames up to the specified MTU size. The valid range is from 1500 to 8184. --- Don Leeper <[EMAIL PROTECTED]> wrote: > The problem started when we notice a slow connection > at times. We checked > everything and called HP. They informed me that > sometimes the intel NICs > don't function great when set to "auto". I then > switched one of the windows > boxes to a set duplex, (100 full) and it seemed to > help a lot. I noticed the > same on my redhat box and just wanted to change it > there as well. It did > help out a lot to manually change it on the Windows > box. The redhat box is > doing ok though. Can't tell too much just when doing > downloads or something. > > don > > -----Original Message----- > From: Jeff Kinz [mailto:[EMAIL PROTECTED] > Sent: Thursday, March 06, 2003 7:46 AM > To: [EMAIL PROTECTED] > Subject: Re: NIC duplex > > On Thu, Mar 06, 2003 at 07:16:08AM -0900, Don Leeper > wrote: > > I was informed the mii-tool will do it. I have > Intel nics, and it seems > that > > when I am able to force them to the correct duplex > as my switch, they run > > better. It seems that between the NIC and my HP > switch it is best to > > manually change the duplex to whatever the port on > the switch is set to. I > > know that auto detect usually works pretty good on > Linux but according to > HP > > support it was a good idea to change it. I can > easily change it on a > windows > > box but I didn't know an easy way to change it in > Redhat. It would be nice > > to be able to change it in the network config > gui.(for anyone from RedHat) > > Yeah - some of the folks who work in this area are > aware of the need but > it looks like it might be a tough one to crack. > > They haven't' a consistent way to do it from the > command line, much > less a GUI. > > One thing I read said you should not have full > duplex turned on when the NIC > is connected to a switch. What are you setting the > duplex, full or half? > > Have you noticed any performance benefist/problems > either way? > > -- > Jeff Kinz, Open-PC, Emergent Research, Hudson, MA. > [EMAIL PROTECTED] > copyright 2003. Use is restricted. Any use is an > acceptance of the offer at > http://www.kinz.org/policy.html. > > > > -- > redhat-list mailing list > unsubscribe > mailto:[EMAIL PROTECTED] > https://listman.redhat.com/mailman/listinfo/redhat-list > > > > -- > redhat-list mailing list > unsubscribe > mailto:[EMAIL PROTECTED] > https://listman.redhat.com/mailman/listinfo/redhat-list __________________________________________________ Do you Yahoo!? Yahoo! Tax Center - forms, calculators, tips, more http://taxes.yahoo.com/ -- redhat-list mailing list unsubscribe mailto:[EMAIL PROTECTED] https://listman.redhat.com/mailman/listinfo/redhat-list
