[Info-vax] invisible vax

[John E. Malmberg]

On 2/17/2016 2:41 AM, nierveze at radio-astronomie.com wrote:
> hello again,
> maybe I did not explain well:
> first everything works well ,excepted lynx,I'll explain below,so we
> could stay here and say ok,but there is a 'mystery':the adsl 'box' is a
> router with an local network and an internet connection to that
> network,until now all the machines that were connected to the local
> network(192.168.*.*)were visible from outside (from my isp)

That is an extremely bad condition.  Most LAN protocols do not have 
enough security for that configuration.

> now all are visible (pcs under windows95/98 and above,linux
> machines,even the nintendo games of my child,but not the vax.I have
> changed nothing to the vax.

There are several active botnets that are continuously scanning for such 
machines to take them over.  There is a high probability that at least 
some of your machines may be part of a botnet if your configuration is 
or was what you describe.

Or are you having issues translating your issue to english?

A normal configuration, as described below, is to have all of your 
systems invisible to the internet, but able to access the internet as 
long as they initiate the connection.

So it sounds like your problem is that the Internet is invisible to your 
VAX, which is an entirely different condition, and a common problem when 
setting up a home network.


You need a firewall router between your LAN and the Internet and that 
firewall router when working properly will by default make all your 
machines invisible to the Internet.

The firewall router makes all your systems use one public TCP/IP address 
when connected to the internet, and gives each of your system a private 
IP address though NAT.

> I think it does not come from vms,but from difference in the
> software  of the box,and it has no consequence on the functionnality
 > of everything.

 From your description you just recently installed a different 
firewall-router than what you are using.

On the firewall router, you need to have set what TCP/IP address it is 
using for the LAN.  And then you need to divide up the LAN address pool 
into static and DHCP assigned IP addresses.

The off the shelf firewall routers normally only allow 256 IP addresses.

So if your local network is 192.168.x.*, all systems in the network must 
have the same "x" and a mask of 255.255.255.0 in order to communicate.

The systems also must have their default gateway set to the LAN IP of 
the firewall router.

> For lynx :the problem is not in unzipping a downloaded file,it
> happens  when trying to access to remote site,not a local page
 >  (it eliminates vms/lynx),I tested with a simple page on my site
>  where I was sure there is no zip file to download and I still get
> the error message (unable to decompress file).

Please, Please use paragraphs with blank lines.  Reading one big block 
of text takes much longer and is much harder to understand.  And two 
spaces after a period., one space after a comma.

> I'll try another version  of lynx.  Another test I did :lynx is ok with
> all sites on linux.  This also does not surely come from the
 > vax/vms/ucx/lynx because it happened suddenly when I moved from
 > satellite internet to adsl internet.

This sounds like a mis-configuration between the firewall router and the 
VAX.

My guess is that:

  A: the non-VMS machines use DHCP and so they
     auto-configured themselves.

  B: The VMS system either had a fixed IP address and has not
     been updated to the new internal network IP or its DHCP
     client is not compatible with your new firewall router.

  C: You do not understand how to do manual TCP/IP configuration,
     because otherwise you would have both figured the above out
     on your own, and you have not presented any of the data
     that is actually needed to solve the issue.

And in order to fix this, you need to learn:

1. How to configure a local TCP/IP network on your firewall router so 
that you know what the fixed range is and what the DHCP pool is and how 
to change them.

2. How to assign a fixed TCP/IP address to your VAX, which depends on 
the TCP/IP program that is installed. There are at least 3 different 
possibilities based on the version of VMS you posted earlier.

It is very possible that the DHCP client on the VAX is not compatible 
with the DHCP server on your new firewall router and you will need to 
switch to using a fixed configuration.

Either that, or you new firewall router uses a different set of IP 
addresses than your old one and the fixed IP address of the VAX was not 
changed to match.

Once you understand those two things, you should be able to fix your 
problem in minutes.  And each issue should not be too hard to look up on 
the Internet.

Regards,
-John
wb8tyw at qsl.network