SG 300-20 bandwith problem

[arnobeck23]

Hello,

I've just bought a SG 300-20 switch, but I have a big problem.

I have just configured it's IP, everything else is deactivated (QoS, ...), my computers are well connected as gigabit ports.

But, the bandwith is very low, around 50-250KB/s. As I expected something well over 20MB/s.

Could you help me fix this ? Perhaps something I don't know and need to be configured.

Please help me.

[Ivor Diedricks]

The switch forwards at wire speed by default - you don't need to setup anything. What might be happening here is autonegotiation between the computers/servers and the switch is not negotiating the correct speed. On the switch ports connecting to the endpoints and on the computers/servers, try turning autonegotiation off and setting the speed and duplex to the same on both sides of the link. Start by setting just two ports (fixed Gig /full duplex) on the switch and same settings on endpoint NICs, testing between those two endpoints then move on and add more. It's important to try to isolate the problem and then move on to others. Also, you can reach out to the Cisco Support org:

http://www.cisco.com/en/US/support/tsd_cisco_small_business_support_center_contacts.html

[arnobeck23]

All my ports are auto negociating in gigabit.

I don't think it's the problem.

[Willard Dennis]

Have a similar problem, low data transfer rate and am also seeing packets dropping between end nodes... Here's the result of an iperf test between two nodes which both nego'd a 1Gb/FDX link with the switch:

server229:~$ iperf -c server231 -t 10 -d

------------------------------------------------------------

Server listening on TCP port 5001

TCP window size: 85.3 KByte (default)

------------------------------------------------------------

------------------------------------------------------------

Client connecting to server231, TCP port 5001

TCP window size: 51.6 KByte (default)

------------------------------------------------------------

[  5] local 192.168.164.229 port 33330 connected with 192.168.164.231 port 5001

[  4] local 192.168.164.229 port 5001 connected with 192.168.164.231 port 55236

[ ID] Interval       Transfer     Bandwidth

[  5]  0.0-10.0 sec  43.8 MBytes  36.6 Mbits/sec

[  4]  0.0-10.2 sec  55.6 MBytes  45.8 Mbits/sec

...I should be seeing about ~940 MBits/sec instead of > 50...

BTW, this is on a "V02" switch, with the latest firmware:

#sh ver

SW version 1.3.0.62 ( date 02-May-2013 time 14:55:01 )

Boot version 1.1.0.6 ( date 11-May-2011 time 18:31:00 )

HW version V02

I have opened a Cisco SBSC case on it, so we'll see how it gets troubleshot...