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jszrules · Feb 8, 2008, 11:59 AM

Hi,

Have an 800MHz iMac G4. For the past day, the internet is spotty on some applications (i.e. web browsers, Mail, Software Update) while other apps that rely on the internet work fine (i.e. AIM, Meteorologist). If a page loads, it will load very slowly with errors, but usually it times-out and says the connection to the server could not be established. Same goes for when I click 'Get Mail'...50/50 chance that any, not all, of my accounts will fail to connect and show up with that caution '!' icon.

I originally thought the problem was the ISP, but all the internet apps on my other machine, HP laptop, seem just fine. Both are using ethernet and the wireless on my router is disabled. I tried disconnecting the ethernet from the HP to test if the Mac apps would improve and they do not.

Any suggestions?
Thanks.

Big Mac · Feb 8, 2008, 12:33 PM

Have you run traceroutes using Network Utility? If you do a traceroute on an inaccessible server, you should be able to figure out where things are getting dropped.

Cold Warrior · Feb 8, 2008, 05:38 PM

flush your dns cache

In Terminal, type 'dscacheutil -flushcache' then press Enter.

You may not have that tool. If not, use 'lookupd -flushcache' then Enter.

No quotes on any commands.

jszrules · Feb 9, 2008, 12:59 AM

Thanks for both of those tips. When I got back home tonight, everything seemed to be running back to normal. Not sure what happened, but I'll take it. Could it have been that the dns cache flushed itself?

jszrules · Feb 9, 2008, 02:44 PM

It's happening again. Not sure why this is so on-and-off. I tried traceroute on one of the many sites that wouldn't load and it went through a bunch of IP addresses before showing * * * repeatedly.

What does that tell me?

What does flushing the dns cache actually do?

jszrules · Feb 9, 2008, 04:40 PM

I restarted, problem persisted. I flushed DNS cache, problem still persists.

Again, AIM and Meteorologist are working just fine.

Clicking Get Mail works 50% of the time. The other times, one or all of my accounts end up with the caution '!' sign.

Loading websites in browsers is slow 50% of the time. Sometimes they never load at all. When they do load slowly, there are always several errors in the Activity menu.

I appreciate any ideas on how to fix this problem. Thanks.

Cold Warrior · Feb 9, 2008, 05:46 PM

Create a new user and see if your issues persist with that account. If they do, then the problem sounds system-wide. My next step would be an archive-install.

jszrules · Feb 9, 2008, 07:24 PM

Thanks for the response. Happens on the other user as well. However, some other observations:

1) I said earlier that AIM and Meteorologist work fine, but I noticed that AIM does take a while to Sign On and sometimes Meteo takes a little longer to refresh, so it might be an internet-wide problem.
2) Network Diagnostics periodically shows that 'Internet' has failed or 'Server' has failed, sometimes both
3) Network Diagnostics periodically that it cannot fix the current networking problems and to check with my ISP that my settings are correct. After the 'Internet' gets the green light again, it then says that my network configuration has changed and Click OK for the next step.
4) I said earlier that my HP laptop appears to be working fine. Now I'm noticing some symptoms on that machine, as well. They are not as prominent as on the Mac, but sometimes pages in HP don't load at all or load with errors.
5) I plugged my Mac directly to the modem, leaving out the router, and the problem persists.

What are all of these symptoms of? If it is simply an ISP problem, then why does AIM behave normally and not kick me off after it finally signs on...even while webpages might not load?

Chuckit · Feb 9, 2008, 08:15 PM

It sounds like a problem with your ISP to me. I can't think of anything else that would explain inconsistent problems that affect multiple systems. I'd try calling them to see if they know what's up.

Cold Warrior · Feb 9, 2008, 10:29 PM

Originally Posted by jszrules

What are all of these symptoms of? If it is simply an ISP problem, then why does AIM behave normally and not kick me off after it finally signs on...even while webpages might not load?

Sounds like an ISP problem or either your broadband modem is messed up.

As for AIM, it could simply be more tolerant of and patient with network problems.

datachump · Feb 9, 2008, 11:16 PM

Another possible explanation is that your ISP is throttling you, i.e., restricting your data flow in an effort to improve overall network congestion. Who's your ISP? Mine's Comcast and they just started doing it to me here in Jersey. My symptoms are just like yours. Rather infuriating, actually, but Comcast has always been vile. Check out this link:

Comcast tweaks Terms of Service in wake of throttling uproar

jszrules · Feb 10, 2008, 05:31 PM

Looks like you guys are right. I called my ISP and they are having issues with their DNS data server. They said it has been going on for 3-4 days, which is exactly when I started experience sluggishness. Don't know why it's taking them so long to fix. Thanks for all your responses.

Cold Warrior · Feb 10, 2008, 05:37 PM

Use OpenDNS. Plug their servers into your Mac for an all-around quicker 'net experience.

OpenDNS | Providing A Safer And Faster Internet

jszrules · Feb 11, 2008, 12:32 AM

Thanks for the tip, I might look into that. The site says to write down my current DNS settings in case I watch to switch back, but the DNS Servers field in Network Prefs is blank. Even my router says 0.0.0.0.

I'm not too sure how all this Dynamic IP/DHCP/DNS stuff works...even after reading that thread on OpenDNS from last week. Is there anything I do need to jot down? Anything else I would need to change before entering OpenDNS's IPs in that field?

Thanks for the continued help.

Big Mac · Feb 11, 2008, 02:06 AM

If even your router doesn't have any DNS addresses, I wouldn't be surprised by Internet problems. If you connect through DHCP the client (whether it's your router or your computer, in the case of a direct connection) should be getting DNS addresses automatically. If not you can call your ISP and ask for them, or you can use OpenDNS.

besson3c · Feb 11, 2008, 02:37 AM

Originally Posted by Big Mac

Have you run traceroutes using Network Utility? If you do a traceroute on an inaccessible server, you should be able to figure out where things are getting dropped.

This is actually not a very reliable troubleshooting technique, as many firewalls block these SYN packets.

besson3c · Feb 11, 2008, 02:39 AM

It is also a possibility that your DSL/cable modem might be folding... I used to have a problem similar to yours (long time ago though). Is your modem provided by your ISP?

Judge_Fire · Feb 11, 2008, 11:01 AM

I'd give the OpenDNS thing a go, too, or check whether the DNS settings on the Mac match the functioning ones on the PC.

Cold Warrior · Feb 11, 2008, 03:12 PM

Originally Posted by jszrules

Thanks for the tip, I might look into that. The site says to write down my current DNS settings in case I watch to switch back, but the DNS Servers field in Network Prefs is blank. Even my router says 0.0.0.0.

I'm not too sure how all this Dynamic IP/DHCP/DNS stuff works...even after reading that thread on OpenDNS from last week. Is there anything I do need to jot down? Anything else I would need to change before entering OpenDNS's IPs in that field?

Thanks for the continued help.

Don't worry if there's nothing there or if there's no current DNS entries to write down. Your OS will get them automatically via DHCP. Just input the OpenDNS IPs at your router and or Mac OS level.