Unable to login with PPPoE (2.10-RELEASE x86)

Chris Turner c.turner at 199technologies.com
Thu Jul 7 03:08:03 PDT 2011



On Thu, Jul 07, 2011 at 10:50:46AM +0200, Georg Bege wrote:
> The funny thing is, addresses do get resolved (if I dont have any
> default) I dont get anything (no dns/resolving).
> But ping doesnt get through nor any kind of connection.

Do I have this correct:

 - without the route assignment, dns lookups are working
 - with the route assignment, dns lookups are not working?

I didn't actually see the address assignment in your ifconfig
output - was the ppp0 device output truncated or ?

If I am correct, it sounds like perhaps some data is flowing but
not all - which could indicate an MTU mismatch  

Though I don't have direct pppoe experience on FreeBSD/DragonFly -
I did once use the OpenBSD implementation (which uses a userspace daemon
rather than the netgraph device) -

I had some issues with the mtu matchup which caused some issues -

My archived configuration had :

 set mtu max 1492
 # set mru max 1492

so you might try commenting out the mru portion?

What does the ping of e.g. the remote gateway, show exactly?
host unreachable or something else?

Its been a while since I debugged an MTU mismatch but iirc 
if you can ping the gateway but not something else (like say your upstream
 dns server ) and the routes look ok (and tcpdump is showing the packets 
flowing out )

you can set some combination of ping -p and -D to detect the mismatch

again, IIRC, I think e.g.:

ping -p 1500 <routed IP? gateway IP?>
ping -p 1492 <routed IP? gateway IP?>
-> works
ping -D -p 1492 <routed IP? gateway IP?> 
-> works
ping -D -p 1500 <routed IP? gateway IP?> 
-> fails

or something like this - I'd verify what I'm saying with some searching :D

or maybe someone can chime in?

that wouldn't explain why the config is working on one but not the other,
though I do recall that some of the default settings might be different
w/r/t freebsd, etc. in ppp from previous adventures with PPP (using GSM devices)

good luck!

Cheers,

- Chris







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