Intermittently losing my hardwired Internet connection

[GanChan]

I'm using a 2013 MacBook Air connected to the Internet via Ethernet using a j5 Create USB 3.0 adaptor. Every so often, I'll simply lose my connection -- sometimes for a second or two, sometimes for more than a minute. It always comes back, seemingly on its own. Sometimes I will try shifting the cord or connector a bit and get results, but I don't know whether that's legit or just a coincidence.

What do you think might be the problem? My cable modem is rock solid, my Ethernet router seems to be running fine (but who knows). The Ethernet cable is just a couple of years old, and the connectors aren't damaged. My laptop seems to stay online when running Wi-Fi.

Any troubleshooting thoughts?

 

[JohnDS]

Try a different USB port and a different ethernet cable. If that doesn't work, it is likely the USB adaptor causing the problem. Try a thunderbolt to ethernet adaptor instead:

http://www.apple.com/shop/product/MD463LL/A/thunderbolt-to-gigabit-ethernet-adapter

 

[GanChan]

Yeah, this is the second USB adaptor I've had trouble with, although it's much better than the cheapo one I used previously. Would a Thunderbolt adaptor offer an inherently more stable connection than is possible over USB?

 

[JohnDS]

I have used the thunderbolt adapter with no problems.

 

[kschendel]

I've been using the Tbolt to ethernet adaptor since 2013 without problems. I agree it's probably the USB adaptor, less likely the cable, even less likely the router.

I used to have to replace my home router every couple years; they do fail on occasion, and strange dropouts can be one failure mode. I wouldn't rush to blame the router, though, until you've tried everything else, or unless other network devices are seeing dropouts as well.

 

[jeremysteele]

Yeah, this is the second USB adaptor I've had trouble with, although it's much better than the cheapo one I used previously. Would a Thunderbolt adaptor offer an inherently more stable connection than is possible over USB?

Silly question - but did you use the same cable with both adapters? If so, try another cable.

 

[belvdr]

I would perform a constant ping from both laptops. This ensures full Internet connectivity is not lost and can help isolate this.

If the ping is failing on both systems, it is something upstream (i.e. cable modem, router, ISP).

 

[GanChan]

Any chance it might be the motherboard? The adaptor is fairly new, and both the router and the cable modem are giving me normal indicator lights. I guess the ethernet cable could be failing (and I admit to stepping on it on a few occasions), but how often do they go bad?

I suppose the ISP could be throwing out spotty service. The fact that the lost correction usually corrects itself after a few page refreshes would seem to point toward brief drops in service. Plus, I'm in an apartment building where lots of people are constantly using devices, so maybe it's something like dirty power or mini voltage swings affecting the components or the adaptor....

 

[belvdr]

Any chance it might be the motherboard? The adaptor is fairly new, and both the router and the cable modem are giving me normal indicator lights. I guess the ethernet cable could be failing (and I admit to stepping on it on a few occasions), but how often do they go bad?

I suppose the ISP could be throwing out spotty service. The fact that the lost correction usually corrects itself after a few page refreshes would seem to point toward brief drops in service. Plus, I'm in an apartment building where lots of people are constantly using devices, so maybe it's something like dirty power or mini voltage swings affecting the components or the adaptor....

Normal indicator lights mean nothing. My cable modem always looks fine, but can be throwing T3 timeouts.

 

[kschendel]

I once wasted an hour of my time (and an unusually helpful Verizon phone tech's time) by not substituting an ethernet cable when it was an easy thing to try. If you don't have to fish through wall or anything, try a new cable before moving on to other suspects.

If you have dirty AC power, installing a mini UPS for your router may extend its life, assuming that it's OK today. Both APC and CyberPower make small UPS units suitable for routers and similar small equipment. I rather doubt that power is your immediate problem, although it's not impossible.