Painfully slow internet connection on OS X...

September 19, 2005 1:17 PM

Is it possible to test an iMac's (OS X) network card? Other suggestions for why I'm getting a slow Net connection?

My computer was working fine (iMac G5) until a few weeks ago when something happened with the display. I checked into it and found a press release from Apple that computers with my serial number had a defective something re: video so I brought it in to be fixed.

So, now I have it back (after 10 days without) and the internet connection is painfully slow. I spoke to my service provider (high speed cable connection) and the guy says that when he pings my modem it's all working fine but when he pings my particular computer he gets packet loss (100 packets sent, 62 returned).

He says that he thinks something is wrong with my network card. I have no idea how to check it or its settings without bringing it back to the Apple store (very time consuming and not at all convenient without a car).

Mefites -- any suggestions for things I can try at home before resorting to the store?

posted by dobbs to computers & internet (15 comments total)

To test the connection between your modem and the computer:

In the Network pane of System Preferences, select the TCP/IP tab under "Built-in Ethernet" and see what the Router address is. Open Network Utility, select Ping, enter the Router address, and check the results. You should get consecutive "icmp_seq" numbers. If there are gaps, that's packet loss. Try it several times.

Beyond that, I think the Hardware Test CD that came with your computer can test the Ethernet port (check you manual for details of how to use it).
posted by cillit bang at 1:40 PM on September 19, 2005

cillit bang, thanks. I did the pinging you suggested about 20 times with 20 pings per time and got 0 packet loss each time. Each ping took 23 - 30 ms; don't know if that's average or not.

I will look and see if I have a hardware test cd.
posted by dobbs at 1:52 PM on September 19, 2005

You were getting 23 - 30 ms to the router (or modem)? That is WAY too high unless I'm mis-understanding what you're pinging. I have computer -> router -> modem here and when I ping the modem I get times of 3 ms. I ping the router and I get < 1ms.
posted by Dipsomaniac at 1:59 PM on September 19, 2005

That's pretty normal. Try pinging apple.com or google.com and see what results you get. Should be 100-500ms, 0% loss.

The idea of pinging your computer individually sets off my bullshit meter. Generally speaking it isn't possible to access anything beyond the modem from outside. Ask to speak to someone sensible.

(btw I think these days Hardware Test is on the standard install disk and not a separate CD)
posted by cillit bang at 2:07 PM on September 19, 2005

Okay, I ran the full hardware test and everything worked out.

The guy on the phone was pinging my modem fine and said he was having probs with the computer. He had me shut off the firewall and then pinged the computer and told me about the packet loss.

I will try to ping apple.com and see what happens.
posted by dobbs at 3:21 PM on September 19, 2005

Okay, something's weird now. Everything's faster once I ran those tests. It was taking over a minute to load Cnn.com pre-tests and now it's like 3 seconds.

I pinged Apple 3 times (20 pings per) and got just over 100ms each with no packet loss.

Could running the tests have done something?

I had rebooted several times previously so it couldn't just be that.

Weird.
posted by dobbs at 3:25 PM on September 19, 2005

Okay, and now I pinged the router IP again and got 45% packet loss the first time and 0 the next 3 times. :(
posted by dobbs at 3:27 PM on September 19, 2005

google.com gives me all under 85ms 0% loss.
posted by dobbs at 3:29 PM on September 19, 2005

Okay, so my internet got slow again and I went back and pinged google 10 times and got 5% loss every time. I pinged Apple and got loss every time between 5 and 60%.

So, what does this mean? How can I tell if this is my computer or my internet provider's fault?
posted by dobbs at 4:30 PM on September 19, 2005

In descending order of likeliness:
1) Line
2) Network cable
3) Modem
4) Computer

Get the first three checked out before you go to the Apple Store.
posted by cillit bang at 4:56 PM on September 19, 2005

those sounds about right.

troubleshooting a network cable is a bitch, because we all like to believe that they never stop working. But they do, and you never figure it out, because, well, why the hell would it be the network cable. Might as well try another cable.

First thing you should do is power cycle your modem, and then your router. See if that improves things. I'd try that before contacting your ISP because they're gonna have you do that anyways, and they will seriously waste your time reading off a script until they put you through to someone who knows what they're talking about.

i've never had a bad NIC, but I wouldn't say it's impossible (see bad network cable, above). it is weird that your computer is dropping packets like that. It's also weird that he could hit it, but i guess if you aren't using NAT, that'd be about right.
posted by fishfucker at 6:07 PM on September 19, 2005

fishfucker, what do you mean by "power cycle your modem"? I unplugged it for 5 mins and plugged it back in and the lights bleeped on and off in a weird pattern and then settled on online.

I have not tried another cable as I don't have one handy but I'll try and find one.

Thanks!
posted by dobbs at 6:35 PM on September 19, 2005

that's the one, dobbs. Power-cycling is just unplugging and plugging back in.

i'm actually getting 27 - 76% packet loss with my macintosh wireless card right now (with a two bar signal, according to the taskbar) so if you figure out anything handy, let me know.
posted by fishfucker at 12:39 AM on September 21, 2005

after killing the DNS servers that I added in randomly yesterday, however, things seem to be working fine. Which is weird, because macs should CACHE dns so one should assume if I could hit any site it wouldn't be a problem (ie, i was having trouble with hitting websites that i'd already hit, which isn't consistent with DNS problems), but now that i've removed them it's smooth sailing on the web (so far). So hey, shot in the dark, but who knows -- there's lots of black magic on the mac side, i've found.
posted by fishfucker at 12:41 AM on September 21, 2005

I spoke with someone else at the provider and he agrees something's fucked. They're sending out a tech and giving me a new modem.

Thanks, all!
posted by dobbs at 8:55 PM on September 21, 2005