Problem setting up ADSL modem using PPPoE HOWTO

Laird · n00b Joined: 06 Aug 2007 Posts: 15

Hi all, this is my first post.

I'm trying to get an ADSL connection up and running. I've received the ethernet ADSL modem and my ISP has confirmed that my line is set up for ADSL and that they use PPPoE. I've physically connected the modem and all the lights are green. Now I'm trying to configure Linux to recognise the connection by following the document, HOWTO Connect using PPPoE.

I've followed all of the steps carefully except that I've substituted ppp1 for ppp0 because I already have a dial-up modem using ppp0.

When I get to /etc/init.d/net.ppp1 start though, I don't get the output that the HOWTO describes. Instead, I get this:

didymos · Posted: Mon Aug 06, 2007 11:14 am Post subject:

Yeah, I wrote that actually. You missed this bit:

Laird · n00b Joined: 06 Aug 2007 Posts: 15

I didn't miss that although I did re-emerge it because I saw that there was a later version available. I now have version 2.4.4-r9 installed.

Laird · n00b Joined: 06 Aug 2007 Posts: 15

Nice work on the HOWTO by the way. It reads clearly.

Laird · n00b Joined: 06 Aug 2007 Posts: 15

Hmm, I've just noticed in the /etc/init.d/net.lo file the following lines:

didymos · Posted: Mon Aug 06, 2007 11:52 am Post subject:

didymos · Posted: Mon Aug 06, 2007 11:54 am Post subject:

OK, wait: which version of baselayout is this?
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Thomas S. Howard

Laird · n00b Joined: 06 Aug 2007 Posts: 15

I think we're thinking the same thing... I'm in the process of emerging the latest version:

didymos · Posted: Mon Aug 06, 2007 12:12 pm Post subject:

Yeah, that should fix it. I'm going to have to change the wiki page. I didn't realize things had changed like that since the 1.11.* versions.
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Thomas S. Howard

Laird · n00b Joined: 06 Aug 2007 Posts: 15

Yes, that fixed it. I reckon that it would be a good idea to add that to the wiki page.

I still have a problem though: my connection still does not come up. For example, ifconfig does not show ppp1, it only shows ppp0 (my dial-up connection). Checking in /var/log/syslog, I find the following entries that appear to correspond to my invocation of /etc/init.d/net.ppp1 start:

Laird · n00b Joined: 06 Aug 2007 Posts: 15

More information:

didymos · Posted: Mon Aug 06, 2007 2:16 pm Post subject:

What does the following show:

Laird · n00b Joined: 06 Aug 2007 Posts: 15

I don't have the ip command - which package do I need to emerge to gain it?

didymos · Posted: Mon Aug 06, 2007 2:28 pm Post subject:

It's in iproute2. I thought it was one those packages that was always emerged as part of system. Guess not. It's good to have it around, but you can also just use the "route" command. It's the same information, just formatted a bit differently.
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Thomas S. Howard

Laird · n00b Joined: 06 Aug 2007 Posts: 15

OK, thanks. route gives:

didymos · Posted: Mon Aug 06, 2007 2:50 pm Post subject:

I take it the DSL will replace the dial-up connection, so try using the "defaultroute" option with ppp1. Stop ppp0 then start ppp1 and see if the connection will finally come up. You can always start ppp0 back up.
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Thomas S. Howard

Laird · n00b Joined: 06 Aug 2007 Posts: 15

didymos · Posted: Mon Aug 06, 2007 3:15 pm Post subject:

You take personal checks? I'll also need a self-addressed, stamped envelope, at which point the check will be in the mail.

Anyway, I'm out of ideas right now. The only thing that comes to mind is the cable to the DSL modem. Maybe it's just not quite seated in one or both jacks. I have to take off anyway, but I'll try and come up with something less desperate than "loose cable". Unless it works, in which case it wasn't some random idea but the product of razor-sharp intuition.
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Thomas S. Howard

Laird · n00b Joined: 06 Aug 2007 Posts: 15

No worries, thanks for your help so far Thomas. I think that sometime after the shops open this morning I'm going to purchase a new network card that I can't really afford, just because I saw in a thread elsewhere that it seemed to solve someone else's similar problem (one of the Intel cards apparently wouldn't work with PPPoE / DHCP... I know, I know - sounds pretty wild but hey, I'm desperate here myself).

Laird · n00b Joined: 06 Aug 2007 Posts: 15

Oh, and, by the way, I had tried the loose cable trick already. I hadn't tried it on the phone jack yet though and there was a pleasing inwards movement leading to a temporary feeling of "This is it, baby!" which quickly dissipated when reality kicked in and the same error ensued...

didymos · Posted: Tue Aug 07, 2007 1:08 am Post subject:

So, did it work? Out of curiosity, what was the card you thought might be the problem?
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Thomas S. Howard

Laird · n00b Joined: 06 Aug 2007 Posts: 15

The problem is almost completely solved with no need to buy a new network card. I hope that you'll forgive me for not answering your question as to which network card I have but it would take some digging around and it seems irrelevant now - it's an onboard chip and I seem to recall that it's an Intel variant. Tell me if you'd still like to know and I'll try to find out more specifically.

It seems that I misunderstood the workings of the ADSL modem. It's a Netgear DM111P modem and to get it working I had to:
* set up eth0 as a dhcp client - the modem then assigned me address 192.168.0.2
* browse to 192.168.0.1 to set up the modem
* enter my username and password in the appropriate place and reboot the modem - it then handles the PPPoE connection itself
* leave eth0 set up as a dhcp client - now that the modem has username/password and connects, the address assigned is no longer 192.168.0.2, but is rather the ISP-assigned address for the ADSL connection. If I want to configure the modem again I guess I have to leave the phone connection unplugged so that I get assigned 192.168.0.2 again and can again access 192.168.0.1.

I'm a little confused about exactly how it's relaying traffic because I have a strong firewall set up but when I run an external portscan it finds most ports "closed" rather than "hidden" and it even finds two open ports. I'm guessing that those ports are on some interface that the modem itself is exposing, rather than on my ethernet card. But that would mean that it's not forwarding incoming connections and I would be unable to run e.g. a web server - I'll have to investigate this.

The main problem that I have now though is that even though eth0 becomes the default gateway when I bring eth0 up, eth0 is no longer the default gateway when the lease is renewed - and the DHCP lease is set to 300. So every few minutes I have to manually type in route add default eth0, which is silly - there has to be a way to configure things better. My /etc/conf.d/net file currently looks like this (minus comments):

didymos · Posted: Tue Aug 07, 2007 5:29 am Post subject:

This is why I prefer not to let the DSL modem handle PPPoE. But first, for the routing, try not setting it yourself and let DHCP do it. The ISP's server ought to pass along routing info, which the DHCP client can set whenever a lease is taken. As to using the modem without the built-in PPPoE client, from the manual it appears you can choose to have it use "RFC 1483 Bridged or Routed Ethernet", which would allow you to use pppd to connect and the modem will just act as an Ethernet-ATM bridge. This also takes care of the forwarding and firewall issues, by giving full control over traffic and ports to the Linux box. If that's the case, then eth0 can be statically assigned 192.168.0.2 and you can access the modem whenever you want.
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Thomas S. Howard

Laird · n00b Joined: 06 Aug 2007 Posts: 15

Wonderful - it's all working now using pppd. Turns out that the menu option was RFC 2684 rather than RFC 1483 but I can forgive them their mispromotion - it works.

Thanks so much for your help! The juicy goodness of broadband is mine!!! Yeeeeeeha!

Three things remain.

Firstly, I was wrong about the ports being left open by a modem interface - turns out that my firewall rules covered only ppp0 and not ppp1, so it was my fault that ports were visible, and not the modem's. Apologies to Netgear for any malignment that they suffered.

Secondly, I'm not sure how I would statically assign 192.168.0.2 to eth0 given that in the net config that you provide, config_eth0 is set to "null". I tried, after pulling ppp1 up, running ifconfig eth0 address 192.168.0.2 and I received this error message:

didymos · config_eth0=( "192.168.0.2/24" )