Computer cannot connect to another computer on different network switch

[Hanz Jason Fernandez]

Hello geeks! I have 10 computers connected to switch1 and 5 computers connected to switch2 (about 40 meters apart).

My problem is I suddenly cannot connect to all of the computers inside the switch2 from all of the computers inside the switch1 and vice versa.

I already tested the cable connecting switch1 and switch2 and it's working fine. (Used cable tester, connected a laptop to the cable that the switch1 is using and its working)

Tested all of the ports of each switches and found it good.
Computers can connect to other computers inside switch1 same in switch2
Took switch1 and brought where switch2 is located and used 1meter long cable, connect to other pc and its working.

What else did I miss? Please help me with this. Thanks in advance.

 

[bigpinkdragon286]

Is your long run of cable running past any points of high interference?

 

[Hanz Jason Fernandez]

None. I have been using that cable since 2008. Just encountered the problem yesterday.

 

[bigpinkdragon286]

Try different ports on the switches, or different switches altogether? Perhaps your switch is unable to generate enough signal if it's been heavily burdened for many years of broadcasting at high power over a long cable? I've had some pretty long runs that over time had to have switches replaced, as ports, and even entire switches went bad.

Is it safe to assume you've power-cycled both switches? 🙂

 

[Hanz Jason Fernandez]

Yes I already did. Tested all the ports too. Replaced good and working switches but the same problem occurs. I try to replace the cable now and I will let you know what will happen.

 

[bigpinkdragon286]

I'm still skeptical of interference. Just because the cable has operated in the position it's been in for years, doesn't mean something new hasn't begun affecting it.

Cable connections can become loose over time. Have you scrutinized the crimped connectors at both ends? Are the network switches saying that the ports your 40 meter cable is connected to are connected, and that there is activity occurring on those ports? Wiggling the ends as they plug into the port may reveal a flaky electrical connection.

Is the cable in a location where it could be subject to foot traffic? Is it in a ceiling where it runs near any florescent lighting, transformers, high voltage lines, inductive chargers for things such as cellular phones, CRT monitors, speakers, power distribution panels, microwave ovens or other high wattage appliances, etc.?

 

[Hanz Jason Fernandez]

Thanks bigpinkdragon. After replacing the network cable things go smoothly. Didn't notice a big speaker hanging below the ceiling where the cable run. I just made a detour for the cable 😀

 

[bigpinkdragon286]

Sounds like you got things sorted and back in working order then? Glad to help brainstorm you in the right direction! 🙂

 

[Hanz Jason Fernandez]

Yeah big thanks to you bigpinkdragon. But I got the same prob in different department. I already replaced the cable but to no luck the prob still exist. It runs 88 meters. Hope you could help me with this too. Thanks in advance

 

[bigpinkdragon286]

88 meters is near the limit for the length a network cable can run, and that is provided conditions are good, and you're using solid core cabling. Since it sounds as though you are in a building, you're probably picking up scads of interference, whether you realize it or not. My recommendation is switch your long interconnects to fiber optic, which is well suited for long distances and nearly impervious to interference, or upgrade your cable, if you can't find the source of your interference. Ideally, if you upgrade your cable, you should be running a solid core, plenum rated, shielded, Cat 6a cable.