On Mon, 2004-07-19 at 09:45, sam@xxxxxxxxxxxxx wrote: > Hi, > > i'm running Fedora Core 2 on my server - which, for the most past works > quite well.. kudos to the dev team. However, i have a minor problem i > cannot seem to fix and is thus: > > i have two network cards ( sis900 and usb200m ) and the first is connected > to my dsl300+ (dlink) modem at 10mbit and the other is connected to a > 10/100 switch that feeds the local lan. if i unplug the dsl300+ from the > rj45 my local lan works quite fast 8MBytes ftp transfers etc to the local > net via the usb200m. however if i plug the modem in i only get 120kbyte > transfer speeds and such. i have switched the modem to the other nic and > the same thing happens. for some odd reason i can only get good speeds to > / from the server to the local net if i only make the local net nic 10mbit > with mii-tool OR unplug the modem and thus get 100mbit speeds.. > > help! > > regards, > Sam. So if you disconnect the modem (10Mbit) the transfers are fast on the LAN side. And if you set the LAN NIC to 10Mbit and connect the modem to the other NIC your transfer speeds are fast? Have you looked at the stats on the interfaces to see if you are taking any errors? ifconfig -a will give you a listing of each interface. Pay attention to the RX and TX lines, you will see counters for errors, dropped, overruns, and frame. If for some reason you are getting errors on packets they will be retransmitted. Lots of errors will result in very poor performance but the transfer will still get through due to the TCP/IP protocol. Also what type of switch are you using? I have seen some switches that have problems negotiating the right settings. When using 100Mbit connections you want to have full duplex set. For 10Mbit connections half duplex is usually the default. If you have a duplex problem between the NIC and the switch you will see the error count increase during a transfer. >From the description it almost sounds like the interface connecting to the modem is forcing either duplex or speed settings on the other interface. Have you checked that using mii-tool in both configurations? -- Scot L. Harris webid@xxxxxxxxxx It's not hard to admit errors that are [only] cosmetically wrong. -- J.K. Galbraith
