Network Slow?

Perryg114

Senior member
Jan 22, 2001
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I have made some recent upgrades to my network and it is slower than before. I upgraded the router and my Gigabit switch. The new router is a Bufflo WHR-HP-G54 running Tomato. The old router is a D-link 614+. My old Gigabit Switch was a Netgear GS105. The new switch is an HP J9077A 10/100/1000Mbps ProCurve 1400-8G.

I was getting 300Mbps file transfers between any two computers on my network. Now I am getting about 170Mbs file transfers. I swapped out the switch to the old one and nothing changed. I also unhooked my server and my HD Homerun tuner from the network for these tests. I have not had time to swap out routers again and am dredding screwing up my network for a couple hours messing with routers.

I can't understand why a router that is upstream of the switches would effect the network speed but that is the only thing that is different now. I also defragged hard drives just to make sure that was not messing things up.

I have a cable modem and the output of that goes to the WAN port of the router and one of the LAN ports on the router is connected to my switch. The other computers are hooked to the same switch.

What would cause the network speed to drop? Am I getting interference that is slowing down my transmission speeds or could the router have some effect? I am using CAT5e cables. 170kbs seems a bit crappy for a gigabit network, 300kbs I can live with.

Perry
 
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Fallen Kell

Diamond Member
Oct 9, 1999
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That does sound like something is seriously wrong. Those HP ProCurve switches are good stuff. Try running a test with only the switch connected to the systems (setup static IP addresses on your systems for this) and see what happens. The only things I can think of would be something with your frame size (possibly the router you have does not support jumbo frames and as a result your systems are not using them, whereas the old router might have supported it, or had it enabled).
 

spidey07

No Lifer
Aug 4, 2000
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That is terribly slow if you're measuring it in kilobits/sec. Local transfers should be in the hundreds of MEGAbits/sec. Make sure all network cards and switch ports are set to autonegotiate speed and duplex and the cables aren't homemade - those are far and wide the most common causes performance problems.
 

NesuD

Diamond Member
Oct 9, 1999
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Disconnect everything from your switch including the router except 2 computers. Test transfer speed. If the speeds are good switch one of the comps out for another. Rinse and repeat until problem isolated or all are found to be good. Your trying to eliminate a possible problem NIC here. Had a chattering nic on my home lan and it caused all sorts of craziness. If everything is testing slow then I call switch. If everything is good reconnect Router. If the problem comes back you have pegged the router. Poorly routed cabling possibly. Make sure your runs don't run side by side with power runs for more than a few feet. The idea is to eliminate possibilities.
 

Perryg114

Senior member
Jan 22, 2001
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These are Mbps not kbps sorry my bad. Speeds were about .3 Gbps and now are about half that. Still 170Mbps is slow for gigabit. These are with all machines running Motherboard NICS.

Why does the router need to support Jumbo frames since it is 10/100 and is up stream of the switches?

If I fix the IP addresses on two machines with the same sub net can I operate without a router in XP or do I need to do something ad-hoc?

Perry
 

Fallen Kell

Diamond Member
Oct 9, 1999
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It is just something that I have seen (in terms of the jumbo-frame support). What might happen is that the system will not use jumbo frames when talking between each other on the GbE link due to not having jumbo frame support on the router. There are multiple ways to use jumbo frames:
* On a port by port basis, where everything "downstream" from a given port is known to support jumbo frames (typically performed by a router or setting on a managed switch).
* Using 802.1q Virtual LANs, where jumbo frame and non-jumbo frame devices are segregated to different VLANs.

Your previous setup may have supported jumbo frames at the router level. And thus, everything on your subnet may have been able to use jumbo frames because everything downstream from the modem device may have had jumbo frame support. The new router might not support jumbo frames, and thus, unless you segregate the GbE switch by putting it in its own VLAN, you will be limited to 1500 frame size, not the 9000 that jumbo frames would use. As for segregating on a VLAN, you would still need to get a router to route to and from that VLAN which would support jumbo frames...

Again, this is why I brought up the issue.
 
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Perryg114

Senior member
Jan 22, 2001
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Is jumbo frame support hardware or firmware driven? If it is the latter then it is a Tomato problem.

Perry
 

spidey07

No Lifer
Aug 4, 2000
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Jumbo frame support by any device does not affect the negotiation of TCP max segment size (MSS). You're barking up the wrong tree unless the transfers use UDP.

Are you using homemade cables or self installed cabling?
 

Perryg114

Senior member
Jan 22, 2001
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Well I was just fishing. So what you are saying is that its not the router? What should I be checking? Yes I am using home made cabling but it is the same cabling that I have been using. I get gigabit lights on all devices.

Perry
 

spidey07

No Lifer
Aug 4, 2000
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Classic symptoms of a bad cables. It can be fast with some devices but not others and getting a link light means nothing, just that there is an electrical pulse on the wire, it doesn't test anything.
 

Madwand1

Diamond Member
Jan 23, 2006
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Measure the network performance in isolation from the file transfer performance, using e.g. iperf version 1.7:

server: iperf -s
client: iperf -c server -l 64k -t 15 -i 3 -r

where client is the name or IP of the machine running iperf -s.

E.g.

F: \tools\bench\iperf>iperf -c amd-vista -l 64k -t 15 -i 3 -r
------------------------------------------------------------
Server listening on TCP port 5001
TCP window size: 8.00 KByte (default)
------------------------------------------------------------
------------------------------------------------------------
Client connecting to amd-vista, TCP port 5001
TCP window size: 8.00 KByte (default)
------------------------------------------------------------
[612] local 192.168.0.100 port 20447 connected with 192.168.0.149 port 5001
[ ID] Interval Transfer Bandwidth
[612] 0.0- 3.0 sec 328 MBytes 918 Mbits/sec
[612] 3.0- 6.0 sec 327 MBytes 915 Mbits/sec
[612] 6.0- 9.0 sec 327 MBytes 915 Mbits/sec
[612] 9.0-12.0 sec 327 MBytes 914 Mbits/sec
[612] 12.0-15.0 sec 326 MBytes 913 Mbits/sec
[612] 0.0-15.0 sec 1.60 GBytes 914 Mbits/sec
[612] local 192.168.0.100 port 5001 connected with 192.168.0.149 port 56940
[ ID] Interval Transfer Bandwidth
[612] 0.0- 3.0 sec 341 MBytes 952 Mbits/sec
[612] 3.0- 6.0 sec 339 MBytes 949 Mbits/sec
[612] 6.0- 9.0 sec 339 MBytes 949 Mbits/sec
[612] 9.0-12.0 sec 339 MBytes 949 Mbits/sec
[612] 0.0-15.0 sec 1.66 GBytes 949 Mbits/sec
 

Perryg114

Senior member
Jan 22, 2001
768
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Ok so how do I install this in windows? I downloaded it but it seems a bit complicated.

Perry
 

Jamsan

Senior member
Sep 21, 2003
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Ok so how do I install this in windows? I downloaded it but it seems a bit complicated.

Perry
Put the exe on your C:\ on each computer. On one computer, go to a command prompt, navigate to the C: (type in CD\ ), then type iperf -s

That command starts the server portion of iperf. On the other computer, open the command prompt and navigate to the C:\ again. This type, use the second command (iperf -c othercomputername -l 64k -t 15 -i 3 -r where othercomputername is the name of the first PC. If that doesn't work, try it by IP.
 

ebaycj

Diamond Member
Mar 9, 2002
5,418
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These are Mbps not kbps sorry my bad. Speeds were about .3 Gbps and now are about half that. Still 170Mbps is slow for gigabit. These are with all machines running Motherboard NICS.

Why does the router need to support Jumbo frames since it is 10/100 and is up stream of the switches?

If I fix the IP addresses on two machines with the same sub net can I operate without a router in XP or do I need to do something ad-hoc?

Perry

Just buy an atom board with at least 1 gig-e nic, and use OpenBSD + PF to do your routing (with jumbo frames on the gig-e port). Problem solved.
 

Perryg114

Senior member
Jan 22, 2001
768
4
81
Well I got it to work. I must have gotten the wrong version or something. I found the download with just the .exe file.

According to the test the first half is showing about 700Mbits/s

The second half is around 400 Mbits/s

I was looking at Madwand1's data and both where over 900Mbits/s and my second half of the test is around 400 Mbits/s.

I just ran the test with the default options and I got 250 Mbits/s.

I would post the result but it is a .jpg image. How does one insert an image on here without hosting it somewhere and posting a link?

Perry
 
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