[noelieg]

I started this question under OS X Troubleshooting but it was suggested I move it here, so here's what there is so far:

I am running OS 10.4.5 on a G5 iMac.
After several months of use with no problems, this week I discovered that I am unable to connect to several websites I am accustomed to visiting frequently. These are not 404 errors. Safari and Firefox both give me the message that they "can't connect to the server," and Netscape says the "connection was not accepted." Examples of problem websites are: nytimes.com, daypop.com, democracynow.org, and as I go through my bookmarks I come up with a new problem website for every 25 or so bookmarks.

I had monkeyed with some of my system settings including activating the firewall which I deactivated with no better results. I cannot remember if there
was anything else I did which could affect the web connections with the firewall off. I repaired permissions just in case--no change. It was suggested that I make one of the problem sites my home page on Safari--that did no good.

I sent a message to the NY Times via webmast@nytimes. com asking if there was some reason I should suddenly have a problem connecting--it didn't get spit back at me, but it has yet to be answered.

Out of ideas as to what else to try. Any help out there? If not, any ideas what site I might visit which might be of help?

A RESPONSE:
>You may want to switch to a different DNS server(s). Post your ISP and geographic location >and maybe someone can recommend you some.

MY REPLY
>Oh, dear. Now we're getting into territory which I've always found a bit murky, but I'm willing to try. Any idea WHY things would suddenly go bonkers on me after so many months?

>My ISP is bellsouth.net, and my geographic location is Gainesville Florida, US.

>It was also suggested on another forum that I try the traceroute utility or, if ignorant as to how to use it (that's me), the Network Utility, so I tried the latter, but, of course, I'm not sure what to make of the results. Here's one which seems to indicate more failure:

>traceroute to www.nytimes.com (199.239.136.200), 64 hops max, 40 byte packets
>traceroute: sendto: No route to host

This result came under the LOOKUP tab:

>; <<>> DiG 9.2.2 <<>> www.nytimes.com
;; global options: printcmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 11332
;; flags: qr rd ra; QUERY: 1, ANSWER: 4, AUTHORITY: 0, ADDITIONAL: 0

;; QUESTION SECTION:
;www.nytimes.com. IN A

;; ANSWER SECTION:
www.nytimes.com. 260 IN A 199.239.137.245
www.nytimes.com. 260 IN A 199.239.136.200
www.nytimes.com. 260 IN A 199.239.136.245
www.nytimes.com. 260 IN A 199.239.137.200

;; Query time: 23 msec
;; SERVER: 205.152.144.23#53(205.152.144.23)
;; WHEN: Sat Mar 4 11:34:22 2006
;; MSG SIZE rcvd: 97


A REPLY:
>Check out this FAQ: http://www.dslreports.com/faq/11703

>ghporter usually stalks the Networking forum, so reposting your thread over there could be fruitful.


OK, that's the end of the thread. I went to the FAQ suggested, but it's all from a Windows standpoint. I went to my ISP's site and found for my area the primary and secondary DNS addresses. My TCP/IP setup does not require me to enter a DNS address, but I tried entering the secondary address, then attempted to access the NY Times site with no luck.

Thus far no one seems to think that this has anything to do with my computer or something I inadvertently did to the settings. But what could have happened to gum up the works after the many months I've been working without incident?

Help or direction to someplace where I might find it would be sooo appreciated.

noelieg

[f1000]

Originally Posted by noelieg

OK, that's the end of the thread. I went to the FAQ suggested, but it's all from a Windows standpoint.

In OS X, you can use Network Utility to ping IP addresses.

Try some of these alternative DNS servers: http://www.dslreports.com/faq/12703

[noelieg]

Aaaarghhh!

I called Bellsouth.net, my ISP. They told me to do something I haven't done since I left OS 9, and that was to restart with the SHIFT key down. I didn't know that was something which still worked with OS X. So I did it--it took FOREVER for it to progress from the grey Apple, and while I waited (and I did this twice) the fan came on and made a terrible racket, then it went off and eventually the desktop appeared...and Safari brought up the NY Times site and another site I had trouble with.

So, what does this mean? A conflict? I used to be a whiz at troubleshooting such things in the pre-OS X days, but now I don't know where to start.

Must I now move this thread to someother category?

noelieg

[f1000]

Originally Posted by noelieg

So, what does this mean? A conflict? I used to be a whiz at troubleshooting such things in the pre-OS X days, but now I don't know where to start.

It could be just coincidence. Are you using a router? What Startup Items do you have?

[noelieg]

It could be just coincidence. Are you using a router? What Startup Items do you have?

Not a coincidence if I restarted w/o the shift key, found the problem returned, and restarted again with the shift key depressed and problem disappeared, right? No router. I start up w/ Safari, Eudora, iTunes, Dashboard.

What gets turned off when starting with shift depressed?

noelieg

P.S. Thanks for sticking with me on this.

[f1000]

OK, go to Preferences/Accounts/Login Items and list what you see there. My guess is that your network issues might have to do with Eudora.

[ghporter]

You probably just dumped the DNS cache. This is something the computer (the OS) uses to decrease time taken to resolve URLs you use a lot. It is also possible to get a DNS cache corrupted, which will do bad things like point your browser to the wrong Internet IP address. In your case it looks like it was pointed to a nonexistent address, but sometimes you can get your cache hijacked by clicking on links on a malicious site.

You can clear your DNS cache with lookupd in Terminal. Enter "lookupd -flushcache" (no quotes) and that clears it just fine without a restart-though you may need to restart your browser.

[noelieg]

f1000 was on the right track, only it wasn't Eudora causing the problem, but something called Peer Guardian which was supposed to provide some security when downloading bittorrents. Now that I've removed it and its startup thingies, everything is fine.

I can never get used to the totally weird s_it that goes wacko. I'm not even going to bother inquiring how a conflict like this would cause only some, not all, URL's to not work.

I've always said that one never learns anything about one's computer until something goes wrong. Fortunately or unfortuantely for me, things have been whizzing along smoothly for a long time with OS X. This is what I get for commenting aloud that I never have any problems with the computer now that I've been using OS x!

Thanks for all the help, fellas. This was the only Mac forum (including the Apple forums) where I got any responses.

noelieg

[endlessracingz]

I have this same problem but what you guys are discussing here in the thread is over my head can anyone help me?!

[ghporter]

See the second paragraph in my post above? Follow those instructions-you don't have to understand precisely what it's doing for it to work. In short, that clears out stored lists of URLs (like "www.website.com") and their real Internet IP addresses (like 123.234.123.234). Sometimes this storage gets screwy, and sometimes it gets bad information. Clearing it out is a good idea in any case.

[endlessracingz]

ghporter I did as what you posted but it didn't fix the problem. I still have the same issue as noelieg had. I really need to figure this out since I need a lot of the websites for school related things.

[endlessracingz]

Can anyone else please help!!! noelieg hasn't been on here in forever and probably wont be back and I still have the problem!!

[ghporter]

If you did precisely what I said, you should have noticed that it took a little bit longer to connect to sites-but only for a little while. That would be the DNS cache refilling. The next step is to see if it's really a DNS problem or your browser. Have you tried connecting to these sites with, let's say Firefox as well as Safari? If you can't get to the sites with multiple browsers, then it's not likely a setting issue in any one of them. The next step is to open Terminal again and type "ping www.site.edu" (where you substitute the real website's URL for the dummy I put in, and again no quotes). You should get something like this:

Code:
Last login: Fri Aug 24 17:59:25 on console
Welcome to Darwin!
Serene:~ Glenn$ ping www.macnn.com
PING www.macnn.com (207.58.150.187): 56 data bytes
64 bytes from 207.58.150.187: icmp_seq=0 ttl=57 time=47.800 ms
64 bytes from 207.58.150.187: icmp_seq=1 ttl=57 time=48.321 ms
64 bytes from 207.58.150.187: icmp_seq=2 ttl=57 time=49.527 ms
64 bytes from 207.58.150.187: icmp_seq=3 ttl=57 time=48.629 ms
64 bytes from 207.58.150.187: icmp_seq=4 ttl=57 time=47.941 ms
64 bytes from 207.58.150.187: icmp_seq=5 ttl=57 time=47.999 ms
64 bytes from 207.58.150.187: icmp_seq=6 ttl=57 time=48.447 ms
^C
--- www.macnn.com ping statistics ---
7 packets transmitted, 7 packets received, 0% packet loss
round-trip min/avg/max/stddev = 47.800/48.381/49.527/0.542 ms
Serene:~ Glenn$

Use the "Control-C" key combination to end the pings. Note that the ping command uses DNS, so if it's working you'll get an actual Internet IP address in the ping output, but if not, you'll get a message that says the server could not be found.

Let us know which way things go.

[endlessracingz]

I tried it and all I get is

Code:
PING www.zabpike.com (216.185.128.200): 56 data bytes
^C
--- www.zabpike.com ping statistics ---
138 packets transmitted, 0 packets received, 100% packet loss

and nothing after. I cannot connect to the site with any browser what so ever.

[ghporter]

Since ping was able to resolve your URL to an IP, that means you have good DNS service and eliminates one potential problem. Now for a new tool: "Open Network Utility and click Traceroute.
Type the domain name or IP address of the final destination and click the Trace button." (From Mac Help). This will basically document how your connection is routed along the way between you and whatever destination you enter. The output (in the window in Network Utility) may make no sense to you at all, but it will to some of us, so copy the whole thing and post it here-go ahead and edit your local WAN IP out to protect yourself. It sounds like there's a potential problem between you and the Internet backbone.

Before you do this, have you turned off ALL of your equipment and restarted it? Turn off/unplug power from everything between where your broadband comes into your home and the computer-including your computer. Now turn on or plug in power to each item, from the wallplate (cable or DSL) to the computer, giving each device a full, timed minute to start up BEFORE turning on the next device. Each of these devices is an embedded microcomputer, and no consumer/small business networking device (even Apple's) is built to "mission critical" standards, so they generally accumulate errors over time-sometimes errors that just plain stop them from working. This "turn it all off" process ensures everything has a hard reset/cold boot and a chance to restart fresh and (hopefully) operational.

[Fred33]

Thanks for that Traceroute tool. I was having the same issue as neolieg and I used the tool and I figured out the issue.

[endlessracingz]

ghporter, I will post what the traceroute comes up with once I get home from work.

You have an interesting point with the power down sequence but I don't think that is the problem since my desktop computer (PC) does not have any issues connecting to the website but my laptop (mac) does.

[ghporter]

Since your laptop uses a different connection to your LAN, it could still be a router problem-I've been sitting right next to my wife and connecting great on my PC while her iBook refused to see anything, and a power cycle on the router cured it (this has happened more than once). DHCP can be tricky, particularly when a router gets goofy just after renewing one address and just before renewing another. Try the tactic and see; all it will cost you is time.

[endlessracingz]

Ran the traceroute and this is what i got:

Code:
Traceroute has started ...

traceroute to www.zabpike.com (216.185.128.200), 64 hops max, 40 byte packets
 1  ***.***.*.* (***.***.*.*)  5.367 ms  2.054 ms  2.832 ms
 2  * * *
 3  * * *
 4  * * *
 5  * * *
 6  * * *
 7  * * *
 8  * * *

[ghporter]

That looks pretty bad. Those * * * lines are timeouts-meaning that there's no response from the next hop. I'm assuming the first IP which you edited out, is your router or something like that. It looks like you aren't even getting anything to your ISP. Have you contacted them?

[endlessracingz]

No I haven't yet but that only seems to happen for a few websites. I can connect to all others fine. Right now I am on this site.

[endlessracingz]

hmm I don't know how this traceroute thing is suppose to work because no matter what website I type in, even Google all get those *** like below

Code:
Traceroute has started ...

traceroute: Warning: www.google.com has multiple addresses; using 64.233.167.104
traceroute to www.l.google.com (64.233.167.104), 64 hops max, 40 byte packets
 1  ___.___._._ (___.___._._)  3.442 ms  2.776 ms  3.829 ms
 2  * * *
 3  * * *
 4  * * *

It MUST be my router... when I use my computer on a different wireless router I can connect to all other websites fine. Even ones I cannot connect to at home.

This is rather confusing...

[endlessracingz]

Any more help????

[ghporter]

If we assume it's your router, we'll have to know all about it and how it's set up. Make, model and version of the router are a good start, and how you've configured it as well. It sounds very much like that particular router isn't getting or passing DNS server addresses. That's supposed to be passed through DHCP. So find out what the router shows for DNS addresses and whether you have that sort of data show up when you run ifconfig through terminal.