Unable to access some internet sites.

CursedHeart · #1 27th March 2005, 01:47 AM

The system accesses the internet through a DSL Modem/Wireless Gateway combo provided by the ISP. Networking is configured via DHCP. I am able to access some internet sites but not others with no apparent rhyme or reason. I can reach sites like redhat.com and of course fedoraforum.org but, I can reach mainstream sites like netscape.com, google.com, msn.com etc. Another PC running Windows XP connects through the same router and can access the any site just fine. Any ideas on a solution?

***bob*** · #2 27th March 2005, 02:22 AM

You might check out this thread which has a bunch of useful information if sites are super slow to load: http://www.fedoraforum.org/forum/showthread.php?t=42943

CursedHeart · #3 27th March 2005, 05:43 AM

The thread you refers to a lag during DNS lookup. DNS lookup goes off without a hitch in Firefox, Up2date, yum, ftp, and nslookup. I don't even have problem with sites being 'slow' to load, the ones that load do it rather quickly. However, a vast majority of sites resolve and hang waiting for a connection.... Firefox stalls at 'Connecting to X' for a good long while before finally timing out. The same sites refuse to load in any application I've tried to connect with, including lynx. There are a number of sites in the Up2date mirror database that cause the application to lock up, indefinitely waiting for a connection yum is a little more forgiving, at least responding to the CTRL+C break command. Up2date will often hang around as a zombie after you select 'Force Close' in the GUI environment often requiring a terminal kill signal, the python front end usually holding out for a kill -9.

The behavior is more like an arbitrary filter blocking connections to some sites and allowing them to others..

Triobe3 · #4 27th March 2005, 08:15 AM

Check preferences in your browser to see if privacy and security settings are not allowing some content and/or sites.

CursedHeart · #5 29th March 2005, 08:58 PM

I looked over the browser settings and I can't find anything that would prevent a web page from loading. I really think this goes beyond browser settings as it has an effect on all internet applications including yum and up2date. There are a large number sites that the system is unable to establish a connection to, eventually it times out. Is there something system wide that would effect the ability to connect to certain websites? The names resolve just fine, its actually establishing an HTTP/FTP connection that the system seems to be having trouble with.

tashirosgt · #6 29th March 2005, 11:45 PM

Can you ping google.com or ping it by using it's ip address ( which must be famous, but I don't know it)?

CursedHeart · #7 31st March 2005, 01:29 AM

Yes, I can ping google.com and/or its ips (216.239.63.104, 216.239.63.99); however, the browser still hangs after DNS resolution at 'Connecting to www.google.com' So where then does the problem lie?

tashirosgt · #8 31st March 2005, 02:48 PM

I have no idea where the problem lies. Is there any pattern to the ip addresses that cause a problem?

I notice on my current machine ( FC2 ) that the man for mozilla indicates that it can be run with some debug flags. So one thought is to find a browser that can be run with debug flags and writes a log in a known place. I don't know if Mozilla/Firefox writes a log. Perhaps someone can tell us.

Since the problem is global, another guess would be that it has something to do with the browsers attempt to use "The X Windows System". But I have no idea why this would depend on particular sites, especially one so apparently plain looking as google.com. See if /var/log/Xorg.0.log has any useful error messages about rejecting clients.

tashirosgt · #9 31st March 2005, 03:14 PM

...and I wonder if there is any pattern to the number and type of cookies that the non-working sites send.

imbob · #10 1st April 2005, 05:13 AM

Amazing that I found this thread! I'm having exactly the same problem. WinXP has no problems, FC3 has the following:

-ping works (IP or URL)
-traceroute works (IP or URL)
-dns lookup works
-pop/smtp works (sometimes slowly, but it works)
-http sometimes works.... more often if I click a link from my email client...odd?!? I also tried other browsers, same results.
-ftp sometimes works
-IM rarely work (yahoo, aim)

oh, and this is all going through an actiontech DSL modem setup like this:
firewall: basic (i.e. just NAT)
DHCP server on
no other speacial features active
It tells me the DNS servers are itself(192.168.0.1) and one from the ISP(205.162.184.2)

even if I put my machine in the DMZ I still have the same problem.

I noticed that sometimes HTTP will work for about 30 seconds and then it will stop working. example: open browser, enter URL, page loads, follow links, everything normal, then just stops loading stuff and waits for the server.

I tried DamnSmallLinux on the same macine and it did just fine (I didn't thoughly test it though) loading HTTP. I suspect FC3 has an issue to work out.. some small setting somewhere that needs to be changed. Basic netoworking problem.

This problem is getting frusterating and I'm considering switching distros if I can't get around it.
-Jon

imbob · #11 1st April 2005, 05:20 AM

I just came across this thread and they are having the same issue.. he seems to have found a fix for himself:

http://www.fedoraforum.org/forum/showthread.php?t=48080

-Jon

Zigzagcom · #12 1st April 2005, 05:35 AM

loop,loop,loop,loop...are you being a troll?

imbob · #13 1st April 2005, 05:46 AM

no, I'm trying to be helpful to both parties. I want my problem solved, so if I help someone else solve it, my problem gets taken care of.

CursedHeart · #14 1st April 2005, 07:49 PM

First off, I have managed to find a fix that you can find at the end of this post. For those of you who just want a quick solution without reading how I got there scroll down and look for the code box.

What follows is a stream of consciousness detailing my actions, conclusions, and reasoning. For some people this may just seem like a waste of time, but for those who really need to understand the B & C I hope this helps.

When I first booted the machine I was unable to access any websites in the X/GNOME/Nautilus environment. I of course decided to investigate the problem on the console level via ping, traceroute, nslookup, ftp, and lynx. I quickly learned that lynx isn't part of the 'Personal Desktop' distribution; however, elinks is. I was able to load the Fedora Project website in elinks and given the late hour decided not to investigate further and shot off a quick post to FedoraForum.org. I didn't get any informative responses and returned to the system a few days later to continue to investigate the problem.

After booting up the system I was surprised to learn that I was suddenly able to access the Fedora Project website. I thought “Cool, it must have just been a fluke.” My optimism was soon shattered when I tried to access something as simple as google.com: no dice. I of course test as many websites as I can off the top of my head; some work, most don't and it strangely seems limited to the major players like Netscape, Microsoft, Google, Yahoo, etc. I of course then came here and created a new thread to detail the evolving problem and hopefully get some feedback on how to correct it.

Shortly after posting my rather poor description of the problem, with some of the worst grammar and word usage issues I've been forced to claim as my own in some time, I got a reply with a link to another thread detailing a sluggish DNS resolution issue. After quickly reading over the posts in this thread I dismiss the problem as unrelated and the proposed solutions as too drastic and all together would require far to much overhead for a system I am trying to set up for a friend who I swear holds the record for rendering a Windows installation completely useless without the help of a virus... tho more than once he has killed an install with a virus of some kind from various sources.

At any rate I decide to turn my attention to other issues and hopefully after distancing myself from the problem I would be able to come at it from a different angle and work it out. Returning to the system a few days later I of course check back to see if there is any insight from the FedoraForum.org community. The only available suggestion is quick to check out and disqualify. After updating some out of date packages via yum I call it a night.

Over the next two days my own efforts as well as some suggestions here in the forum put me into a pretty heavy debug mode. I spend my time on the console looking for log files or anything that might give me some clue as to what's going on with the system. Yesterday, while goofing around in the terminal window with nslookup I switch back to the Firefox window and decide to try Google again. It worked... I was frelling shock that is actually worked. I close the terminal window in my excitement and try another site: no dice. Frell, this is frustrating. Back to Google: no dice. New terminal window and more nslookup. Maybe if I try connecting to Google's IP. Don't ask why it took me that long to try to connect via IP... the only excuse I have is that I start work at 5:30 in the morning and was usually sitting down to work on the system after an 8.5-9 day on my feet and exhaustion isn't one of the best bedfellows for cognitive thought. It works, by god it works. A quick lookup of some more IP's and low and behold, they work; however, any request to an outside source, i.e. an image server or ad server fails. Through more experimentation I learn that if I have Firefox open and use nslookup on the site I want to visit, and any outside source, I can reach it via its registered name as opposed just the IP. It only worked so long as I performed the lookup while Firefox was open and would only persist for the current session. If I restarted the browser I was back to square one. Closing the terminal window often had the same effect.

This of course led me to believe that maybe something was happening during lookup that was causing the problem. Perhaps it was returning an unusable IP or something I still don't know. I decided to revisit the DNS thread and try one of the solutions presented there: disabling IPv6. After rebooting everything worked just fine. I am not sure where the problem was or what caused the applications to hang while attempting to connect, only that it seemed to be caused by IPv6. If anyone has some ideas where I may find more information, log files, core dumps, etc. I'd appreciate it.

The solution is relatively simple. Use your favorite text editor to open '/etc/modprobe.conf' and append the following to the end of the file.

Code:

alias net-pf-10 off
alias ipv6 off

Reboot, hopefully this will resolve the problem.

‡ Of course 'frell' is used to replace a censored word... the source may or may not be self evident... but its fun at any rate.

imbob · #15 2nd April 2005, 01:38 AM

Thanks for posting your success! I also tried turning off IPv6 last night after noticing the same thing about using the IP address in place of the host name. I also added my ISPs DNS server in my resolv.conf file... everything is working great now. Now, I wonder why it does that with IPv6??

-Jon