Mac internet speed

I'm trying to diagnose some internet speed issues on my MacBook. It's happening everywhere I use the internet -- at home (Comcast), at work, at my favorite cigar store. (All are wireless.)

At first, when it was home, I thought it was my service, as my XBox 360 was also exhibiting some internet speed issues. I bounced the router, and the 360 was fine -- but the Mac was not. (Plus, once I got the machine to work and the cigar shop today, it's still exhibiting the behavior.)

The behavior itself is odd -- once a host seems to be found, speed is no longer an issue. (In other words, download speeds themselves are fine -- but getting the request to the server is the issue.)

My gut reaction is that I'm having a DNS issue.

Any troubleshooting advice?

EDIT

On the advice of Josh, I tried a Speakeasy test. Once the site resolved, the speed here at the cigar store was reliably 20+mbps up and 3+mbps down. I expect my home environment to be similar when I get back tonight. As stated above, the issue isn't the download speed itself -- it's the resolution. I may try Am1rr3zA's advice of setting my own DNS if this continues to be an issue. Still soliciting other ideas, however!

John Rudy

Posted 2009-09-21T22:59:03.343

Reputation: 3 267

1if you think it's from your DNS set other DNS service provider for yourelf. like 4.2.2.4 or 4.2.2.3 – Am1rr3zA – 2009-09-21T23:04:02.680

Answers

What does a speed test from somewhere like speakeast.net say? Are the results consistent?

EDIT 1: If you think it's DNS, open the terminal and type: dig www.google.com (replacing www.google.com with the hostname to check. When the results come back look for the line: Query time: ** msec. What is the output?

EDIT 2: Since DNS doesn't seem to be the issue, how does raw HTTP seem to work? In the terminal, try:

HOST=www.google.com
time echo -e "GET / HTTP/1.1\nHOST: $HOST\n\n"|nc $HOST 80

and let's see how long that takes. (Obviously just change HOST= to the hostname to check)

FINAL EDIT: For other people having the same issue, see the comments. The issue turned out to be erroneous DNS servers listed in the network configuration.

Josh

Posted 2009-09-21T22:59:03.343

Reputation: 7 540

Consistently high -- once I finally make it to their site. :) – John Rudy – 2009-09-21T23:30:59.787

Try testing DNS speed, see my revised answer. – Josh – 2009-09-21T23:35:26.047

Now that was enlightening. Results I considered perfectly fine -- 25, 40 msecs. Odd since I'm still exhibiting the behavior in-browser. (And it's not just Firefox 3.5 -- I also see it in Safari, NetNewsWire and Nambu. Hmmm. I'd almost say browser add-on, but I have none for the WebKit-based stuff, and it's affected too ... ) – John Rudy – 2009-09-22T02:20:19.403

I am just troubleshooting bit by bit... please see EDIT 2... :-) – Josh – 2009-09-22T02:27:42.167

Same behavior as the browser, so I feel a little better. Took a total of 10.322 seconds to retrieve Google's home page this way. Normally this operation is borderline instantaneous -- I've rarely seen Google take more than 1 second to pop up, unless I was on my cell phone's connection. :) – John Rudy – 2009-09-22T11:48:15.730

(BTW, thanks for all the help! This is greatly appreciated!) – John Rudy – 2009-09-22T11:48:46.417

1You didn't quite hit the answer, but I'm giving you the accept for all the troubleshooting. Turns out it actually was DNS. I'd been signed into my work network all day Friday, and the DNS & search domains from there persisted. Being inaccessible anywhere else -- even the their wireless network, sans VPN -- they caused the issue. I noted their addresses & removed those two DNS servers and the search domain, and everything's back to normal! Thank you again for the help. For the next guy, can you mention to check the DNS page for errant servers, log and remove them and try? – John Rudy – 2009-09-22T12:01:20.633

@John Rudy -- Glad I could help! I didn't think of that and when dig had such normal results I started to think about other things to check. But I'm glad you figured it out! – Josh – 2009-09-22T12:06:12.107

I wouldn't have gotten there if it wasn't for this answer. And this is now one of the most comprehensive Mac network troubleshooting questions around. :) – John Rudy – 2009-09-22T14:10:41.127

You might try disabling IPv6 if you have it enabled; some networks and routers still have various problems with it. The setting is in System Preferences » Network » Advanced » TCP/IP » Configure IPv6.

mark4o

Posted 2009-09-21T22:59:03.343

Reputation: 4 729

Thanks for the advice, but no change. – John Rudy – 2009-09-22T11:43:39.687