+ 0 Votes Ummm....Lag is an understatement robo_dev 2 years ago For starters, if the switches can only do half-duplex, then switch the firewall settings to match that. Duplex mismatch results in SEVERE performance loss. Running at half-duplex is roughly half the speed of full duplex, since data is moving in one direction only. A mismatch means one device transmits, times out, retransmits, times, out, etc. etc. Full duplex gig delivers something like 800 Mbps, while half delivers around 400 Mbps. If you are running duplex-mismatched gigabit ethernet currently, upgrading your switches will make a very big difference. If you could fix the duplex mismatch, that will solve most of the problem. Keep in mind, by the way, that if the connection to the Internet is only 6MBS, then the speed of the switch uplink does not matter, as long as it's greater or equal to 6MBS.