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Cambo105
10-16-2007, 05:32 PM
I am once again having internet connectivity issues. If I open Konqueror and try to go to the Knoppix website I get this message:

An error occurred while loading http://www.knopper.net/knoppix/:
Unknown host www.knopper.net

Net card config brings up these results:

eth1 Link encap:Ethernet HWaddr 00:16:D3:A8:91:DF
inet addr:128.119.27.174 Bcast:128.119.27.255 Mask:255.255.254.0
inet6 addr: fe80::216:d3ff:fea8:91df/64 Scope:Link
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:1746 errors:0 dropped:0 overruns:0 frame:0
TX packets:43 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:155538 (151.8 KiB) TX bytes:3632 (3.5 KiB)
Interrupt:16

lo Link encap:Local Loopback
inet addr:127.0.0.1 Mask:255.0.0.0
inet6 addr: ::1/128 Scope:Host
UP LOOPBACK RUNNING MTU:16436 Metric:1
RX packets:16 errors:0 dropped:0 overruns:0 frame:0
TX packets:16 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:0
RX bytes:800 (800.0 b) TX bytes:800 (800.0 b)

Does this provide any insight? What should I be looking for when I run netcardconfig?

Harry Kuhman
10-16-2007, 05:44 PM
I don't see anything awful about your netcardconfig info. As before you are sending and receiving packets. And as before, the next step is to try
ping 72.232.180.133then
ping knoppix.netIf the first works and the second fails then there is a problem that is keeping you from doing a DNS lookup on knoppix.net. And I take it we should assume that you can't get to any URL on the Internet, not just Knoppix.net, correct?

Cambo105
10-16-2007, 06:13 PM
Thats correct, I can't access anything. I'll try those pings and report back.

Harry Kuhman
10-16-2007, 06:28 PM
An error occurred while loading http://www.knopper.net/knoppix/:
Unknown host www.knopper.net
I'm not sure why that final colon is in the top url, it shouldn't be and I get an error with it there also (but a different error than yours). I can get to http://www.knopper.net/knoppix/ or just www.knopper.net though.

Cambo105
10-16-2007, 08:19 PM
Here is what I came up with:

PING 72.232.180.133 (72.232.180.133) 56(84) bytes of data.
64 bytes from 72.232.180.133: icmp_seq=1 ttl=48 time=51.4 ms

knoppix@Knoppix:~$ ping knoppix.net
ping: unknown host knoppix.net


Also I tried typing http://www.knopper.net/knoppix/ directly into the browser and I got the same error message. So I guess its a DNS problem? Excuse my ignorance, but what exactly is that and what are the remedies?

Harry Kuhman
10-16-2007, 09:14 PM
.....So I guess its a DNS problem? Excuse my ignorance, but what exactly is that and what are the remedies?
As mentioned in your previous thread, DNS is the system that looks up URL and translates them into IP addresses. You could have answered this yourself with a simple search (http://www.google.com/search?q=DNS). Google is your friend. (AKA: STFW).

In a previous thread here (http://www.knoppix.net/forum/viewtopic.php?t=25578&postdays=0&postorder=asc&start=0) a similar problem was reported and speculated that it was related to how the DNS servers in question were dealing with IPv6 (most users still use only IPv4 and so don't see IPv6 problems, but some of the software on the Knoppix disc apparently supports IPv6). I know they say that they don't support Linux, but this might be a good thing to discuss with the system admin people. Failing that, I would read through the thread that I referenced you to and see if it doesn't give you some things to try. I can't test any of these myself, since my Internet Service Provider limits me to IPv4 (as does my router). There are many different DNS servers that you have access to, changing the DNS server used may help (this is set by DHCP originally but this setting can be changed, see the thread for details). Also, just using a different browser may resolve the issue.

It may be worth it to you to take notes on what DNS server your system is using when it fails, and check it again later if you find it working again. Your DHCP server may be selecting from several DNS servers, and one might be configured in a way that causes this problem, while others are configured in ways that do not. If you were to report this issue with the IP address of the problem DNS server and the IP address of a DNS server that does not cause the problem to the network admin, and explain the problem, then it is likely that they would correct the configuration of the problem DNS server and you would have to deal with it manually in the future.

Harry Kuhman
10-16-2007, 09:21 PM
Here's a thread (http://www.knoppix.net/forum/viewtopic.php?p=89824#89824) that talks about how to disable IPv6 in firefox (AKA IceWeazel).

And, of course, I'm assuming that other people running Windows on the same network and using the same DNS server are not seeing the same problem. A bad DNS server could cause this problem without being an IPv6 issue, but in that case you likely wouldn't be able to post here, and I would expect you to know that the problem wasn't limited to Knoppix users. So unless I hear otherwise I'll stick with my IPv6 theory.

Cambo105
10-17-2007, 09:43 PM
Ok, so here is what unfolded this afternoon, following a tiresome electrical and computer engineering exam nonetheless.

I booted knoppix, and launched firefox. I got the message Checking Compatibility of Add Ons, which lasted for several minutes, then the window just disappeared. At this point, fed up, I just left it and did some calc homework. A few minutes later, the FF browser popped. So I typed about:config and disabled IPv6 DNS, closed FF and reopened. I tried to get to google.com, nothing. So i tried knoppix.net, still nothing. At this point I typed 72.232.180.133 in, and like magic I'm at Knoppix.net. Then i tried knoppix.net, that worked as well. So i tried google.com and that worked too. I searched for "knoppix forum", and thats where I am right now, posting this reply. Is this a predicted course of events?[/list]

Harry Kuhman
10-18-2007, 02:20 AM
Is this a predicted course of events?...
No, not really. Even if plugging in the IP address somehow allowed your system to later link the URL to the IP (it wouldn't), there are other IPs on the Knoppix.net page (such as the google ads) that need their own DNS lookup. I'm not clear on why DNS lookup started working. It may be some delayed action from turning off IPv6 (as I said, I have no hands on experience with IPv6), or it might be something else. Since this problems seems to come and go for you, I suspect it's "something else".

Cambo105
10-18-2007, 02:52 AM
I'm posting this via windows (I had to run a windows program, Quartus II), so I'll try booting up Knoppix later and see if the same procedure yields the same results. Its kinda of confusing and I wish I had more time to really research this and play around with Knoppix.

Cambo105
10-18-2007, 04:40 AM
I booted Knoppix, and again I had the same problems. Firefox opens a "checking compatibility of add ons" window for several minutes, then this disappears, then several minutes later the FF browser pops up. From here I disabled IPv6 again, closed and re opened FF. I tried to access the knoppix website first and that didn't work, so I typed in 72.232.180.133 again, and it worked! Brought me right to the Knoppix site, and I made note of the google adds that showed up on the side. After that I could access any site freely, so here I am. So I guess the same procedure did yield the same result which is rather interesting. But since it takes ten minutes from when knoppix loads to when I can access the net, I am trying my luck with a persistent disk image saved to a USB drive.

Cambo105
10-18-2007, 12:46 PM
The plot thickens...

I booted knoppix this morning, with the command home=scan and I chose the second option down (I forget the exact details) and I loaded my persistent disk image from my USB device. I opened iceweasel (FF) and I my information from last time had been saved (history et cetera), but when I tried Knoppix.net, I got nothing. So again I went to 72.232.180.133 and it worked, and after that everything worked fine. Thats where I am this morning, I still don't fully understand what is going on here.

dram
07-01-2008, 07:56 AM
For consistently good results with dns, I've found it best to place your isp's primary and backup nameservers inside the routers setup page. This helps bypass issues with the little dns-forwarding code inside most soho routers that do not always follow the internet specs and are may be tuned to how other os's/manufacturer's define the protocol. Linux sticks to the exact internet protocol, and sometimes dns can get hung, or be very slow when it deals with these internal router dns-forwarders. You can help bypass it by specifying the real primary and backup dns servers in the router setup page. If you do this, restart networking, or just reboot the computer.

Of course you can use alternate dns servers, like those at the bottom right of the page at opendns.com, but there are others. For security reasons, don't make them up, nor blindly use any that you see in other postings - verify them by visiting the site or use some other form of verification.

For the temporary nature of Knoppix, or if you don't have access to the router, you can temporarily edit your /etc/resolv.conf file, and place your real dns server addresses at the top of the list - leave the one you may have already found (likely to be that of the dns-forwarder, at the bottom.)

I'll use some fake dns addresses here as an example - use the real thing obviously!

Quickly edit:

sudo nano /etc/resolv.conf

Edit somewhat like so:

nameserver 123.45.678.901
nameserver 123.45.678.902
nameserver 192.168.0.2

These are fake/example addresses of course, but this will take affect immediately and will persist until reboot, OR until your system gets a re-lease of it's dhcp address. When a re-lease occurs, you might find that /etc/resolv.conf gets overwritten without the new nameservers, but for the typical knoppix session, this should hold for awhile for those who don't have access to their router setup.