Date   : Tue, 11 Aug 2009 17:28:36 +0100
From   : philb@... (Phil Blundell)
Subject: Econet <> Ethernet

On Tue, 2009-08-11 at 17:17 +0100, Pete Turnbull wrote:
> On 11/08/2009 16:34, Rob wrote:
> > 2009/8/11 Pete Turnbull <pete@...>:
> >> On 11/08/2009 11:37, Phil Blundell wrote:
> >>
> >>> I just checked the manual for my router (a Speedtouch 536) and you're
> >>> right: it can forward UDP or TCP, but it doesn't seem to have any
> >>> provision for forwarding other IP protocols.
> >> I'd be surprised if that's strictly true, partly because I know that
> >> people have linked them to other routers in various ways for various
> >> reasons.  For example I'd be very surprised if it doesn't forward ICMP
> >> (protocol 1), and it might forward IGMP (proto 2) and even GRE (47)
> > 
> > I suspect you are talking at cross purposes..
> 
> Mmm, that's possible -- I didn't stop to think which direction Phil 
> means.  If we're talking about inbound connections, then it might be 
> almost as restrictive as Rob suggests (TCP, UDP, ICMP and just possibly 
> IGMP). Others traffic probably work inbound only if the connection was 
> initiated on the LAN side (ie an outbound connection), and some might 
> not work at all.

Sorry, yes, I was a bit vague in my mail.  I was talking about inbound
WAN -> LAN traffic.

The Speedtouch "games and applications" configuration allows you to have
particular TCP or UDP ports forwarded to internal hosts, but there
doesn't (judging from the manual) seem to be any way of doing that for
custom IP protocols.  Even if the Speedtouch itself can do that, I
suspect there are probably enough other routers that can't for it to be
a bad idea to rely on that.  So, I think the UDP encapsulation is
probably the way to go.

p.