> I was to play with MTU ethernet parameter in my LAN to see if I can get
> any speed improvement and found out that I can't get it more than
> 1500!!! Here is command and error:
>
> [root@athlon root]# ifconfig eth0 mtu 1600
> SIOCSIFMTU: Invalid argument
>
> [root@athlon root]# ifconfig eth0 mtu 1500
> (no error)
>
> But if I do 'ifconfig' alone it shows me that lo (local loopback
> interface) has a MTU=16436 !!!!
>
> Why can't I get my eth0 card to that MTU (even if it would make net
> slower)???

You should have a look at the Ethernet-II frame specification:

[ Preamble ][Dest-addr][Src-addr][ Type   ][         Data        ][  CRC   ]
<-64bits->  <48bits> <48bits><16bits><max1500bytes><32bits>

The Maximum Transfer Unit is the largest amount of data that can be 
transferred across a physical network; for an ethernet physical interface the 
maximum value is 1500.

-- 
Toshiro

Want to buy your Pack or Services from MandrakeSoft? 
Go to http://www.mandrakestore.com

Reply via email to