SRW2048 slow responsiveness

[sean.hayes]

Scenario:

I have a network that consists of the following:

Internet -> Comcast modem -> Linksys RVS4000 router -> 2 x Linksys SRW2048 switches -> LAN connected devices.

Issue

One of the switches is really slow at handing traffic regardless of how many ports are in use. The other is performing well and I have no issues.

On the underperforming switch I can't get to the WebView screen at all. In fact when I try and log in  the switch appears to time out while it's trying to draw the screen and  dumps me back at the login prompt.

The underperforming switch I think has had sub-par performance like this for a while and I feel I have now spent enough time testing and that I have isolated the issue to the switch.

What I've done in terms of troubleshooting

I have disconnected everything from the switch other than an admin laptop and a connection to the RVS4000. I disconnected the other SRW2048 and other devices from the RVS4000 so the admin laptop was the only device on the LAN. The web / network access performance in that configuration is dire - the same as if all ports were connected and operating normally. I switched the switches plugging in the other SRW2048 and disconnecting the sub-par SRW2048 and the LAN/Internet performance is much better and as expected.

I took this time to update the firmware on the sub-par switch so that now runs the following software:

Boot Version:          1.0.0.04 (Date:  08-Sep-2005, Time:  16:57:40)

Software Version:      1.2.2d (Date:  23-Feb-2009, Time:  13:58:42)

Hardware Version:      00.03.10

I didn't update the firmware on the other (working) switch.

However, I found that after this no improvement was made. I also updated the firmware on the RVS4000 while I had the opportunity. Again, no change in the switch performance.

I'm looking for guidance on what other checks  / tests I can do to identify what is making the switch perform like this or any suggested fixes.

Thank you

[David Carr]

Mr. Hayes,

Has this switch been doing this the whole time you have had it or  did it just recently happen?

When you upgraded the firmware, did you do a factory reset of the switch and manually reconfigure the switch. Typically as best practice for me, when i do a firmware upgrade I will factory reset the device and reconfigure the switch. 

Try reflashing the firmware again, and do a hard reset and manually configure the switch, this will let us see if it is software based issue or a hardware issue. 

Another thing you can check for is, if the switch only gets sluggish after it has a lot of devices connected to it, maybe pull back some of the units and test the performance.  If you notice one device is making a significant impact on the performance of the switch you could mirror the port that is connected to that port and see what kind of traffic it is sending and receiving.

[sean.hayes]

Hi David,

I've had the switch for 4 years and over the past few months I've had

reports of slow connectivity in my office. I have 2 other SRW2048s (of the

same vintage) and of course when I was testing the speed I realised I was

connecting to one of the better performing switches. After deducing the slow

speed reports were coming from those connected via one particular switch

that's when I focused more on this one.

During my testing I did unplug all other connections to the switch except

the cable to the router and the cable to my laptop directly connected to the

switch.

I originally saw that the under performing switch didn't have a default

gateway and wanted to address that in the command line and I thought that

would fix the issue. However, I found that it wouldn't accept the gateway

setting giving me an obscure error message which I can't recall. It was at

that point I decided to reset the switch and then upgrade the firmware. I

hadn't planned to upgrade the firmware but I figured it was worth a shot. I

then re-configured the switch setting it's default IP and gateway (and

nothing else). I didn't notice any difference in speed after doing this.

During my testing I found the switch sluggish regardless of the number of

connections. Pings from my laptop (when it was the only connected device) to

the switch were in the region of 2-4 seconds. Connecting my laptop to

another SRW2048 in the same rack (again my laptop was the only connected

device) the pings were in the region of 2-4 ms.

I tried chaining the switches from the router so it would be

Internet->Modem->Router->Switch1->Switch2 but I have it now as

Internet->Modem->Router->Switch1 and on a different router port

Internet->Modem->Router->Switch2. I tried all combinations and left it that

each switch was connected to a different port on the router. Again no change

in performance regardless of configuration.

I don't believe it to be a single device causing the issue as I performed

most of my testing out of hours and with only a laptop connected to do

configuration and speed testing.

I'm confused as to what else to try to narrow down the issue given that I

can't access the configuration of the affected switch and I'm unfamiliar

with other network utilities to analyze the network.

Thank you

Sean

On Wed, Mar 2, 2011 at 8:50 AM, davicarr <

[David Carr]

If you have done all you  can with the software/firmware and the issue is still showing itself and you have removed the connections except for a laptop and still having issues, it could be hardware issues.

Have you tried replacing the switch with another srw2048 to see if the issue is the switch or network?

[sean.hayes]

I haven't but I think you are right.

I'll plan to do that and see what results I get.

Thanks.

On Wed, Mar 2, 2011 at 10:08 AM, davicarr <

[Randomizer1]

I had one that was doing the same thing I found out that it had "BAD CAP SYNDROME"

All of the 1500uFd 6.3 Volt caps were bad all 21 of them had swelled and the ESR had gone from .2 to 10

I replaced them and the Switch is now working fine