poor NIC performance
 

very poor NIC performance

i own a RH 7.3 box with 2 NICs [realtech RTL 8139D], presumably 100 Mbps capacity , this machine acts as a gateway and connects to the internet thru optic fibre cable with one NIC ;and the other NIC shares the connection to mulitple machines thru a hub .
I am running Apache to host a binary resource directory , although my NIC is capable of transfering data at 100 Mbps , still the download speed over LAN is as low as 1 mb/sec . Is there a way that i can increase the transfer rate ?

also

how do i configure "squid" to restrict people from using my public IP as a proxy server . I use Webmin's Interface to configure my server settings !!

any help would be greatly appriciated

I am pretty sure that the cabling has been carried out in a perfect and glitch-free manner

last but not the least the gateway machine is 18GB SCSI HDD , 2.4Ghz P4 Ht , 512MB DDR RAM ,