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Can't access Internet


Peter Chatterton
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Okay Peter let's try to sort this out. You wrote:

 

On the Connections icon (in the bottom right-hand corner of the screen, it looks like two lumps of shishkebob on a stick at a 45 degree angle) if I hover the mouse over it it says "Network is up on interface eth0". If I pull the cable it says "Network is down...".

 

This is absolutely normal, and meant to be this way.

 

> ifconfig eth0

Link encap: Ethernet

HWaddr 00:02:55:8A:69:1D

inet addr: 192.168.2.13

Bcast: 192.168.2.255

Mask 255.255.255.0

inet6 addr: fe8...

Scope:link

RX packets: 343 errors: 0

TX packets: 2332 errors: 0

RX bytes: 37KiB

TX bytes: 167 KiB

Interrupt: 20

 

netstat -r

Dest 192.168.2.0

default 192.168.2.1

 

Looks good, too! Your machine has 192.168.2.13 as IP address.

 

Default route is 192.168.2.1. This means your network routing defaults to that address, which is most probably your DSL Modem. So your machine is connected to it and all well! You'll presumably just have to find out about two important issues:

 

a) DNS service

 

b) firewall issues

 

 

a) Is your provider giving your a DNS server number automatically? If yes, you likely can choose 192.168.2.1 as DNS address on your machine, or obtain it from your modem using dhcp. If no, you should find out which DNS servers your provider is giving you, and use that one. You probably can "ping 192.168.2.1" in the scheme you've given above. If not, temporarily remove your firewall. Can you ping it now? If yes, try to ping the DNS server you are using. (You can end ping by pressing Ctrl-C).

 

b) This is more often a mess than actually doing sth right with home users. Firewalls were never meant to work on the same machine containing user data, but in the middle between "the big wide world" and local networks. I know there's "personal firewalls", but if you don't really know the concept, you can probably stay without one. Correct firewalling is a science on it's own, as you have to understand networking in detail.

 

If your modem provides a hardware firewall, I'd suggest to use that one and leave your local machine without. If you do not want to do this, you should delete previous functionality and set it up anew AFTER your connection is working. (On firewalls and security see also http://www.iks-jena.de/mitarb/lutz/usenet/Firewall.en.html )

 

If you're using shorewall, install iptables-ipv6 also and *deactivate* IPv6 (you actually don't need it, right?) within shorewall.conf (resides in /etc/shorewall). Small editors of your choice are "joe" or "nano"; vi can really be a pain in the ass, especially if you're new. I'd suggest to "urpmi nano" from console window and apply changes. (Shorewall authors advise to disable IPv6, see config file.)

 

I don't know what XP is doing to your modem, just know about Mandriva. :-)

The method above *should* work. I know these problems well because of my own experiences...

 

Good luck,

 

scoonma

Edited by scoonma
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/etc/resolv.conf contains:

search no-domain-set.bellcanada

nameserver 192.168.2.1

nameserver 192.168.2.1

 

In view of my lack of Linux knowledge, this could be a very simple-minded sort of problem; maybe I'm leaving out a basic step. Is there another step after configuring the network in MCC and starting it from the Connections dialog?

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I changed to firewall to let everything thru.

 

In MCC > Mange Hosts, I added the host 192.168.2.1

 

Under network monitoring I connected ethernet:

-- it showed some trailing dots, then

-- "connection complete" and then

-- "not connected"

 

ping 192.168.2.1 worked

 

Konqueror gives the error "Unknown host".

 

In CLI, host linux.org gives "No host could be reached".

 

Under MCC > Manage Connections > DHCP

should there be a DHCP host name?

It's blank.

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[...]

ping 192.168.2.1 worked

 

Konqueror gives the error "Unknown host".

 

In CLI, host linux.org gives "No host could be reached".

 

Under MCC > Manage Connections > DHCP

should there be a DHCP host name?

It's blank.

 

This would be the name of the server giving your local machine it's IP number, 192.168.2.13 in your last case. Is there a reasonable output of "host 192.168.2.1"? If yes, you should add that name here. Not every device capable of providing DHCP service must have a hostname, but it's worth a try (my DSL-Router/Modem has www.routerlogin.com). If not, just leave it blank.

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host 192.168.2.1 also gives "No servers could be reached".

 

I couldn't think of a DHCP host name to give it.

 

No greater problem. If you're sure that the modem does act as a full dhcp server, it should work without hostname (check good handbook, i.e. one that's giving you some technical info). But you need DNS.

 

It seems your modem gives your client a working IP, but does not "forward" a (working) nameserver. So if you're not sure, choose a DNS server manually (i.e. make sure it appears in /etc/resolv.conf afterwards). You cannot do much wrong with this. Just adding more namserver entries won't hurt anything. You may also try to disable the default search domain (don't have to delete the entry, just comment it out by inserting "#" at the beginning of the line.)

 

Plese also check hardware connection again: Is the modem's DSL side on-line (LED status)?

Sometimes DSL and ethernet cables are simply interchanged when both have RJ45 connectors, too.

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I'm using the same cable for XP and Linux, is this okay?

 

I got 198.235.216.130/131/134 from http://www.dslreports.com/faq/7525 and appended them to /etc/resolv.conf and put a # before nameserver 192.168.2.1. Connect ethernet under network monitoring did the same as before:

-- it showed some trailing dots, then

-- "connection complete" and then

-- "not connected"

 

Maybe I should confirm some of my settings:

MCC > Manage Connections > eth0 > TCP/IP > DHCP has 192.168.2.13 but greyed out.

MCC > Manage Connections > eth0 > DNS servers has 192.168.2.1

*it seems not to have noticed my changes to resolv.conf; how do I change this?

*I've tried rebooting but the changes get dropped! (I did apply them as root)

MCC > Manage Connections > eth0 > search domain has no-domain-set.bellcanada

 

MCC > Manage Connections > eth0 > DHCP > DHCP client has dhclient

MCC > Manage Connections > eth0 > DHCP > Assign host name from DHCP address is checked but DHCP host name is blank and DHCP timeout is blank.

MCC > Manage Connections > eth0 > DHCP > Get DNS servers from DHCP is checked

MCC > Manage Connections > eth0 > options has Start at boot and hot-plugging checked.

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I'm using the same cable for XP and Linux, is this okay?

 

Of course! I just meant please make sure you've not plugged your DSL cable into ethernet socket and ethernet cable into DSL socket at your modem. (You can actually spend hours searching for the error if everything else is configured correctly.) Sorry if this was not so clear. Then be sure to be on-line with your provider regarding hardware. Any LED on the modem showing you're connected or data being transferred?

 

I got 198.235.216.130/131/134 from

http://www.dslreports.com/faq/7525 and appended them to /etc/resolv.conf and put a # before nameserver 192.168.2.1. Connect ethernet under network monitoring did the same as before:

-- it showed some trailing dots, then

-- "connection complete" and then

-- "not connected"

 

Maybe I should confirm some of my settings:

MCC > Manage Connections > eth0 > TCP/IP > DHCP has 192.168.2.13 but greyed out.

MCC > Manage Connections > eth0 > DNS servers has 192.168.2.1

*it seems not to have noticed my changes to resolv.conf; how do I change this?

*I've tried rebooting but the changes get dropped! (I did apply them as root)

 

This is some annoying msec behaviour: The system tries to secure itself but does not respect actual changes made by the admin. You can care about this in the next step. First edit your resolv.conf, so that it looks like the following:

 

# search no-domain-set.bellcanada
nameserver 192.168.2.1
nameserver 209.226.175.223
nameserver 198.235.216.134
nameserver 198.235.216.130

 

(First two outside ns entries claimed to be sympatico nameservers: http://www.oclug.on.ca/archives/oclug/2004...ary/037573.html )

 

Then do "chattr /etc/resolv.conf +i". This should prevent the file from being altered.

Afterwards you can "service network restart" and check with "ifconfig -a" what has

happened. Are you able to successfully "ping 198.235.216.134"?

 

MCC > Manage Connections > eth0 > DHCP > Get DNS servers from DHCP is checked

 

I'd uncheck this, then restart the network. How's it now?

 

 

 

Ah - just a moment: I remember some details from my modem times: How do you identify yourself to your provider: Did they give you a login/password combination for your account? In that case ... I have to admit that you do have to use the pppoe option. Then you'd have to configure BOTH eth0 and ppp0; in the following way:

 

In MCC, choose eth0 and NO TCP/IP address at all! No dhcp, nothing. Just leave it as blank as possible.

(Rather looks like disabled when trying to change, but still exists.)

 

For ppp0, choose manual DSL configuration for pppoe and enter your data.

 

By that, eth0 will get it's dynamic net address. Never seemed fully logical to me, but it worked here once.

In that case, you should make /etc/resolv.conf accessible to the system again by: "chattr -i /etc/resolv.conf".

 

Please excuse any possible confusion!

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