[Info-vax] TUN/TAP Like driver any pointers ?

[Simon Clubley]

On 2019-09-05, John E. Malmberg <wb8tyw at qsl.net_work> wrote:
> On 9/5/2019 3:46 AM, El SysMan wrote:
>> Hi VMS folks!
>> 
>>   Working on small a yet another VPN project for Linix and Windoze ...
>>   Thinking about of possibility to implement server/client functionality on VMS.
>> So, is there something like at the FW CD-ROM what i can use to
>> understand what it need to do under VMS to achieve TUN/TAP
>> functionality? Or what i can use as a template to writing my own
>> "tun/tap for VMS" drivers ?
>> 
>>   Thanks for any reference or opinion.
>
> The feature is present even as far back as VAX.
>
> Here is a link to some older documentation that shows up from a quick 
> search.
>
> http://h30266.www3.hpe.com/odl/vax/network/tcpipv42/manage/6526pro_003.html
>
> Look for pseudo-interfaces.
>

Pseudo interfaces are nothing like the TUN/TAP drivers as far as I can see
unless the pseudo interfaces have functionality that I don't know about.

The TUN/TAP drivers create a virtual network interface which allow a normal
user space program to directly read and write packets/frames from and to
the interface as if it was a real network interface.

Basically, you can use the TUN/TAP drivers to create all kinds of
interfaces and functionality in user mode without having to go anywhere
near kernel mode and without having to create your own kernel mode
virtual network interface.

As far as I can see, the pseudo interfaces in UCX are only used to
allow additional subnetting on an existing network interface.

Simon.

-- 
Simon Clubley, clubley at remove_me.eisner.decus.org-Earth.UFP
Microsoft: Bringing you 1980s technology to a 21st century world