Slow Internet Problems

[mcmike100]

I have my Powerbook connected wirelessly to my Dlink DI-624 802.11g router with cable internet access. The computer is only ten feet or so away from the router, and I even bought the bigger external antenna for the router so that the computer in the other room can access the internet.

Even though I have one of the faster internet plans, however, the net is often very slow. Pure download speed is usually very good, but the problems come with simple web browsing and such. The strange part is that usually things load slowly on the first try, but clicking again they load almost instantly.

For example, in iTunes Music Store, double-clicking on a song for the preview often brings up the "Opening URL - Connecting..." window for five seconds or so, but if I immediately cancel and double-click again then the song loads instantly.

Similarly, with web links, clicking once often makes it pause and do nothing as it seems to load the page, but clicking again will make it come right up.

Any idea what's causing this and how I can fix it?

Thanks a lot!

 

[dpaanlka]

Try going to System Preferences, clicking on Network, clicking on Airport, clicking on TCP/IP, and where it says DNS Servers type in the following:

4.2.2.1
4.2.2.2
4.2.2.3
4.2.2.4
4.2.2.5
4.2.2.6

That may work, but it may not. If it does great. If it doesn't, then I don't know...

 

[Makosuke]

That is almost certainly a DNS resolution issue, which is what the above poster is having you test (those numbers are for the Root nameservers, which you don't really want to keep using, but if it fixes the problem it tells you that you're having slow DNS query problems).

I've once seen this happen on a network with a particular router, and it's a really annoying issue since it's hard to pin down. It could be that the MacOS just doesn't like your provider's DNS servers, or that they're not responding in a timely fashion. It could also be that it's having a latency problem with the router. That's EASY to check: Just plug your Mac directly into your modem (DSL or Cable, I assume), and see if the problem goes away.

If it doesn't, it's your ISP's DNS servers. If it does, then your router is not playing nice.

This is sometimes caused when the ISP's main DNS server isn't responding correctly, and so the Mac has to try two before it gets a response. I've seen this happen when a router gets the DNS servers via DHCP (as it's supposed to), but then doesn't get an updated list when it's supposed to, so it's still using an outdated list.

You can test this by powering down both the modem and router for a couple of minutes, then turning the modem back on, wait for it to finish initializing, then turn the router on and wait for it to finish warming up. Again, if that fixes it, you're good.

This problem is, I THINK, caused by when the response to a DNS query doesn't come back in a timely fashion; the MacOS spazzes out on waiting, and so it appears to be taking an inordinately long time to get the reponse. A router-induced delay of some sort might cause this, and it can often be worked around by just manually entering the DNS servers into the MacOS--you can usually look up the ones that your ISP gives you and type them in manually.

 

[mcmike100]

Thanks very much.

Entering those 4.2.2.x DNS numbers seems to have helped.

To find out the real ones given by my ISP, can I use the three sets of numbers listed on my router's setup page?

Under WAN on the Device Information page, it lists the following things:

MAC Address
.....
Connection
DHCP Client Connected
IP Address
.....
Subnet Mask
.....
Default Gateway
.....
DNS
.....

Would those be the right ones?

Thanks!

 

[trainguy77]

Yes the ones listed under DNS would be your ISP IPs try enter those and see if you get decent speed.

 

[mcmike100]

Thanks, it seems to be working!

 

[Makosuke]

Thanks, it seems to be working!

Good to hear that. It would appear that your router is doing DNS resolution internally or isn't passing requests fast enough, if typing them in manually worked.

ISPs rarely change those, so it's probably a near-permanent fix that you can just forget about now, but if you ever have problems in the future, remember to check and see if your ISP has changed its DNS servers so you don't waste time unnecessarily troubleshooting.