SG300 & SG100 not talking?

[ValleyITPC]

Hi all.  I have a 48 port SG300 unit sitting as the main and only switch in an office.  We needed to branch out a couple of extra connections in a room, but didn't want to run the cables, so we just put in a small 8 port SG100 switch, connected that to the wall, then connected two PCs and one WAP (AP541N).  All seemed to be fine, but once in a while, we'll lose connectivity upstream from the SG100 to the SG300.  The two PCs can still ping each other, but we can't get past the walljack/ uplink to the 48 port. 

It used to be inconsistent - days of working fine then just stopping.  Power cycling the SG100 usually fixed it.  If I power off/on the SG100 it'll work for about 5 seconds, then it'll fail again, consisetntly now.  Yet, all ports are working, since the PCs can ping each other fine even if I move cables to ports thatwere used by the uplink to the wall jack and so forth.  It almost sounds like some kind of switch-to-switch issue, not the cabling but whoknows maybe one doesn't like the other suddenly?  Makes no sense. 

CAn anybody theorize, or provide advice?  Thank you. 

[Tom Watts]

Hi Valley one idea would be to set the auto negotiation on the SG300 to manual 1000 full duplex or 100 full duplex and see if it makes a difference.

Have you tried a different port on the SG100 to the SG300 and swapped out wires as well?

-Tom
Please mark answered for helpful posts

[ValleyITPC]

Hi Tom, thanks for replying. 

I haven't yet done those things.  I thought first I'd swap the SG100 with antoher SG100 to perhaps eliminate device-specific issues first.  This is a new customer environment so we haven't traced and marked the network lines yet.  I could tone out that one line though and will probably do so today. 

The SG300 shoud of course be managable to charnge the duplex and speed but the SG100 isn't.  I have tried different ports, but used the same cable.  However, given that we needed a certain PC connected immediately, I took that cable, disconnect it from the SG100 and plugged it dierctly to the PC so it's the PC straight to the wall now, and it has been consistently fine for about 20 hours now. 

So it could easily be the speed/duplex tweaking that could fix, or maybe the actual SG100 itself is an issue in some way, but since it only seems like the combination of the SG100 uplinked to the SG300 has so far been the problem, it leaves me confused and that's why I was suspecting something in their interaction.

I am still going to swap the cable anyway though as well and will post back here when all that's done. 

[ValleyITPC]

I"m at a loss.  Maybe it's the "low-cost factor" (any time you get a bunch of low-cost switches, where all SHOULD be equal, often it's not...).  I particularly like this SG100 units but anyway. 

So, I swapped another switch in, and so far so good after about 40 hours.  I took the supposedly bad switch, brought it back to my office and set it up with a PC, 2 printers, the Internet connection, and a link to the rest of the network and so far, no issues of any kind. 

I haven't tried with all ports, as I'd have to go a couple of days each tmie to give the errors a window of opportunity to start up again.

So, though I don' tahv an answer, I have the results I need, which for now is a working SG100 at the customer site.  Maybe their SG300 needed a reboot so to speak, which it got during a brief power outage the day after I last posted. 

Well, I"ll post a new thread if the switch acts up again, and will then also tweak with the duplex/speed to see what happens.