Brian Marshall <> wrote:

> No problem blocking PPPoE from the loc zone, I'm just not sure the protocol 
> number(s) I would use to achieve that.

They aren't even IP packets, and as far as I can see should not be getting 
forwarded at all. As below, they are ether type 0x8863 or 0x8864 vs 0x0800 for 
More information at

> It may not be anything to do with LCP packets at all, but something from this 
> problem PC is causing the DSL modem to think it is being asked to shut down 
> the ppp connection, in some instances (but not all instances) it even reports 
> "ppp closed by user request" in the ppp log.
> If you have any thoughts to offer I'm all ears...

It might be worth running a packet sniffer and capture the relevant LCP packets 
on both network links. On the loc net you shouldn't be seeing any PPPoEs 
(ethertype 0x8864) packets at all - possibly some PPPoE discovery packets (if 
there's anything trying to use PPPoE you'll see regular PADI packets*). In the 
modem side you'll need to refine the capture as PPPoEs packets will include all 
your internet traffic as well, so you'll need to filter on the PPPoE frame type 
as well to select just the LCP packets.

How often do these disconnects happen ?

* PADI = PPPoE Active Discovery Initiation
Sadly I have a little more knowledge of this than I think I should need having 
had to debug some PPPoE problems over the years :-(

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