troubleshooting a gigabit connection

wpublic · Post by **wpublic** » Mon Apr 10, 2006 7:57 pm

i work with video and do a lot of large file transfers back and forth between 2 systems; they are already networked with static IP's 192.168.1.xxx

one had a gigabit onboard(3COM) so i added a 10/100 NIC and got it set up with the previous settings and works fine. i added a gigabit NIC (Realtek RTL8169) to the other.

the drivers for the gigabit cards are installed. I set up a static IP 192.168.0.99 on one and 192.168.0.98 on the other; 255.255.255.0 subnet mask and nothing for default gateway and DNS. I am using a belkin 25' cat6 (straight) cable. I believe i read in the specs for the realtek card that it can autosense and crossover when needed (MDI/MDX?)

it is showing in network connections to be connected at 1.0 Gbps, but i don't see a dramatic increase in transfer speed. between 2 compressed drives, a transfer of a dvd folder at 4.4 GB would take about 9 minutes on 100 Mb/s and on the gigabit connection(i confirmed that it is using the gigabit to transfer) it takes around 6 minutes for the same transfer.

is this normal or should i be trying something else? I set both of the cards to full duplex and the connection crashed. now they are set to autonegotiate. should i make the cable into a crossover cable?

I just did a transfer and watched it in the task manager, network utilization spiked at around 14% for the gigabit connection. what's a simple way to check for dropped packets?

thanks in advance for any input you may give.

Post by **FlyingPenguin** » Mon Apr 10, 2006 8:51 pm

Hold on - you maintained the existing 10/100 connection between them and then added a 2nd 1Gbit connection between them? That won't work. The computers will only use one connection or the other at one time, and it will preferencially use the connection that has a gateway probably.

You need to disable the 10/100 connection and use the 1Gbit connection exclusively, which means you'll also need a gigabit switch. You'll need the switch to connect them to a broadband modem.

wpublic · Post by **wpublic** » Mon Apr 10, 2006 10:31 pm

yea, i'm looking to catch a deal on a gigabit switch which should eventually solve that one.

hypothetically, could i disable one of the 10/100 and still have the gigabit connection to the other computer that also has a 10/100 connected to the gateway? sort of like this:

|PC|----1Gbps----|PC|_______10/100_______|gateway|

Post by **FlyingPenguin** » Tue Apr 11, 2006 7:22 am

Yes, but you'll need to enable ICS (Internet Connection Sharing) on the 10/100 NIC. THis will setup that NIC as an Internet gateway: http://www.practicallynetworked.com/sharing/xp_ics/

As for transferring files, be aware you're not going to see a 10 fold speed increase in file transfers. Few workstations can actually sustain gigabit speeds. You're running up against other issues: PCI bus bandwidth, hard drive controller bandwidth, caching of the NIC.

Plus few NICs are really capable of full 1Gbit speeds (there's a reason why servers use expensive 1Gbit NICs).

wpublic · Post by **wpublic** » Tue Apr 11, 2006 5:24 pm

thanks. i'll try it out. on compressed drives, i'd be happy with a x2 speed boost.