pppoe configuration and dns name resolution

[RW]

On Sat, 20 Oct 2012 09:42:31 +0530
Jack wrote:

> Hi again,
> 
> This time I disabled DHCP on my fxp0 interface and
> in my adsl modem too.
> But the problem still exists.
> 
> This time I tried both approaches:
>  assigned an IP address explicitly to fxp0, and
> then no explicit assignment to fxp0.

I'd leave fxp0 unset until you've fixed the other problems - it's not
necessary for PPP. 

Modems and routers in PPPoE bridging mode don't normally require any
adjustment or other access so there's probably no need to assign
address anyway.


> I still don' get why FreeBSD is having trouble
> connecting via PPP.

The original problem you quoted was with DNS and
that's explained by the DHCP on fxp0 overwriting resolv.conf with the
router/modem's own non-functional DNS proxy.


As regards ppp.conf mine was simply:

default:
  set log Phase tun command

adsl:
  set device PPPoE:vr0
  set authname <my username>
  set authkey  <my password>
  add default HISADDR


> ppp_adsl_unit="0"
> 
> 
> I tried to specify tun0 interface explicitly,
> but still no luck.
> When I start ppp using:
>       service ppp start
> It shows tun0 is busy.

Don't try to specify the tun device number. I've noticed in the past
that occasionally tun0 becomes unusable and ppp will switch to tun1.
I've seen this happen when I've been restarting ppp a lot. 


> From my understanding it shoud not matter whether fxp0 is
> assigned the  ip address via DHCP server on local lan or via
> manually - at least this concept works on windows.
> 
> But in FreeBSD, if I enable dhcp on fxp0, then
> /etc/resolv.conf is created each time I boot in FreeBSD,
> so the only nameserver being 192.168.1.1, ie adsl
> modem ethernet interface.
> Even if I edit it to include nameservers of my ISP or OpenDNS
> this file is created each time FreeBSD boots, and these entries
> are lost, with only entry being 192.168.1.1
> 

There's no good reason to use DHCP in this case, you can simply set a
static private IP address (typically a high address in the same /24 as
the modem). If you really must use DHCP then it can be reconfigured
globally or per interface  (type apropos dhclient).

  
I notice that the original resolv.conf you quoted was set by resolvconf.
I've never used this so I can't comment on whether it's helping or
hindering. I suspect it aimed at laptops switching between different
networks.