Old tinc version, switch mode not working

[Graham Cobb]

I have been using tinc in routed mode for many years.  However, I tried today 
to use tinc in switch mode and it doesn't seem to be working.

The problem is that my router is running a very old version of tinc!  I am 
wondering if anyone remembers whether a bug like this was fixed...

I have set up two nodes, running tinc, in switch mode.  One is running an up 
to date version of tinc (from debian testing).  But one (call it "router") is 
running an old version:

tinc version 1.0.3 (built Jan 27 2005 10:19:28, protocol 17)

What is happening is that the connections get set up fine, but I can't 
communicate through the switch.  Looking at -d5 I see that when I ping from 
the router to the client, ARP messages are being passed from the bridge to the 
tinc tun interface, tinc receives those (42 byte messages), it forwards them 
to the client, the client tinc receives them, the client broadcasts them to 
its tun interface, the client then receives the ARP response from its tun 
interface, the client sends it to the router's tinc, which reports it has 
received it and is that it is broadcasting it to the tun interface.  But the 
interface never receives it.  The "Rx packets" counter on the tun interface on 
the router remains resolutely at 0 (Tx is going up, and both Tx and Rx are 
going up on the client).

It seems that tinc on the router tries to send the ARP response (and all other 
packets it receives from the client) to the interface but the interface never 
sees it and never passes it up to the bridge.

Does anyone remember a bug like this being fixed?  If so, I might have to dig 
out my cross-compiler environment for the router and build a newer version of 
tinc.  But that will be a long job!

Of course, if anyone can suggest a configuration problem which could lead to 
this behaviour that would be even better!

I'm not hopeful of getting a resolution without building a new version of tinc 
but I thought I would ask anyway!

Graham