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SG200-26 Switch Performance

Unanswered Question
Jul 18th, 2014
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Hi. I did not find information on this elsewhere. We recently setup a small business network in a colo. When we connect directly to the WAN interface with a computer the throughput is fine. The moment we connect the switch it drops drastically. File copies move like mud between machines on the LAN and WAN. Calculations show we are only using a tiny fraction of the link capacity. Since it is not possible to access this switch via CLI there does not appear to be a way to determine something as simple as total bytes or bits the switch forwards. And there also do not appear to be any useful logs. Each port shows total bytes but under Status and Statistics > Interface. Do I have to manually add each one of those? Not a switch I would have bought but I am stuck with it at the moment. Any suggestions would be greatly appreciated.

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Brandon Svec Fri, 07/18/2014 - 12:33
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    Small Business, February 2016

This sounds like a duplex mismatch.  You didn't say which port your uplink is, but if you look at stats for that port do you see dropped packets or collisions?  I would try going to port management > port settings and hard code the port to 100 full or maybe Gig and see how it works.

kbullard00 Mon, 07/21/2014 - 06:39
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brandon thanks for the response. Actually in my research that was suggested and I verified all of that. I also ran Wireshark and there was little packet loss or retransmissions. However, I did manually add up the bytes/sec on each port in the GUI (sure a laborious way to do it since you can't access the CLI on these low-end switches). From the specs for this switch it supports up to 52Gbps. My calcs showed the ports totalled about 120Gbps. I would assume this means the switch doesn't have the horsepower which is not really obvious until I try to copy a large file. It was perplexing that capacity tests at ISPGeeks showed no bandwidth issues.

Brandon Svec Mon, 07/21/2014 - 08:43
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I think the screen shot you showed is total bytes and packets for the interval since the counters were last reset, not per second statistics.  So, I don't think you can calculate from that information how much backplane capacity is being used.

 

That said, what is your WAN link speed and what are your expectations for transfer speed total and per device?  You are correct, this is a low end desk top switch and may not be appropriate for your application or expectations.

 

 

kbullard00 Mon, 07/21/2014 - 08:46
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I refreshed those port speeds several times and they stayed about the same. As far as the WAN link it is 100MBps. Calculations show they should theoretically reach close to 10MBps but file transfer speeds are in the kbps range.

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