[Simh] VAX: tap/tun.

[Andrew Back]

On Sat, 24 Mar 2007, Hans Rosenfeld wrote:

> On Fri, Mar 23, 2007 at 11:35:52PM +0000, Andrew Back wrote:
>> I have tried using 'taptap.c' and this works if I configure say IP on tun0
>> on the host, and attach xq to tun1. But if I then try attaching xq to br0
>> and putting tun1 in the bridge it stops working. I'm guessing this is
>> something to do with tun working at the IP layer.
>
> When using taptap you should always attach your XQ device to the tun
> device not configured for IP on the host (tun1 in your case). If you
> want the virtual ethernet created by taptap to be bridged to a real
> ethernet, you should add the tun device configured for IP on the host
> (tun0 in your case) to the bridge, but there is absolutely no point in
> attaching the simulator to the bridge interface itself.

I've tried this and it works until I add vlan100 to br0. If I'm running 
ping from the host before adding vlan100 to br0 it carries on working. If 
I then stop ping and restart a little while after I get "Destination Host
Unreachable". At this point if I log on to VMS and 'tcpip show interfaces' 
I can see the count for rx & tx packets going up so would suggest they are
getting to the vax via tun1, being sent back, but not reaching the host. 
Adding the interface on the DECnet vLAN seems to break things, which is 
odd considering there is no IP on there (well, save for the autoconfigured 
IPv6 address on the host i/f).

> > Lastly is there any way to create and attach a second xq in the 
simulator?
>
> There should be a XQB device.

Ah, just discovered I needed to enable this from the sim prompt.

Cheers,

Andrew