Film-Tech Cinema Systems
Film-Tech Forum ARCHIVE


  
my profile | my password | search | faq & rules | forum home
  next oldest topic   next newest topic
» Film-Tech Forum ARCHIVE   » Operations   » Digital Cinema Forum   » Change the VNC inbound port on an AP20 and/or DSS200

   
Author Topic: Change the VNC inbound port on an AP20 and/or DSS200
Leo Enticknap
Film God

Posts: 7474
From: Loma Linda, CA
Registered: Jul 2000


 - posted 09-23-2015 10:45 AM      Profile for Leo Enticknap   Author's Homepage   Email Leo Enticknap   Send New Private Message       Edit/Delete Post 
I wondered if there's any way to do this.

I have an AP20 and a DSS200 on the same VPN and I want to be able to establish VNC connections to both of them from the outside.

I initially tried to make this work by using Dolby Show Manager for the DSS200 and VNC for the AP20. I forwarded all the ports my firewall tells me that Show Manager is trying to use to the DSS200 in the router's firewall settings (1098, 1099, 4444, 4445, 49648, 49651 and 61616), but without success - it won't connect from an external IP.

So I'm down to VNC, which uses port 5900 by default. Problem: neither the AP20 nor the DSS200 lets you change the inbound port from 5900 to something else, and unless I can do that, I can't connect to both remotely, both using VNC and both at the same time. To make this work, I need to set up port forwarding on my router settings such that the correct port goes to the correct machine. Neither manual mentions a way of changing the VNC port, and I can't find anything online, either. Does anyone know of any undocumented way? Obviously, I only need to change the port on one of the machines. Many thanks in advance.

 |  IP: Logged

Scott Norwood
Film God

Posts: 8146
From: Boston, MA. USA (1774.21 miles northeast of Dallas)
Registered: Jun 99


 - posted 09-23-2015 10:51 AM      Profile for Scott Norwood   Author's Homepage   Email Scott Norwood   Send New Private Message       Edit/Delete Post 
Assuming that you are using NAT and have access to the router/firewall, you can just redirect different inbound ports to port 5900 of the DSS200 and AP20.

For example, you could port 5900 on the external address to port 5900 on the DSS200 and 5901 on the external address to port 5900 on the AP20.

Then, you need a client that lets you specify the port number. Connecting to the external address at port 5900 will connect you to the DSS200 and connecting to the external address at port 5901 will connect you to the AP20.

BUT, VNC is not secure and should not be used directly over public networks. You really should be tunneling this over ssh or a VPN. If you do this, then none of the NAT translations above apply, since everything runs over ssh or the VPN.

 |  IP: Logged

Leo Enticknap
Film God

Posts: 7474
From: Loma Linda, CA
Registered: Jul 2000


 - posted 09-23-2015 10:59 AM      Profile for Leo Enticknap   Author's Homepage   Email Leo Enticknap   Send New Private Message       Edit/Delete Post 
It's on a VPN, which has been set up such that when you connect to the VPN, it's as if you are plugged directly into the router in the booth (the firewall defining the VPN is upstream of the booth router). If that booth router's settings lets me translate incoming on 5901 into 5900 on a given local IP, I'm guessing that should work. I'll see if this can be done when I'm in this afternoon - many thanks.

 |  IP: Logged

Marco Giustini
Film God

Posts: 2713
From: Reading, UK
Registered: Nov 2007


 - posted 09-23-2015 03:22 PM      Profile for Marco Giustini   Email Marco Giustini   Send New Private Message       Edit/Delete Post 
I can access different devices via VNC when I VPN on a network. Yes, the port is the same but the IP is not! Why should you need a different port?

 |  IP: Logged

Steve Guttag
We forgot the crackers Gromit!!!

Posts: 12814
From: Annapolis, MD
Registered: Dec 1999


 - posted 09-23-2015 06:16 PM      Profile for Steve Guttag   Email Steve Guttag   Send New Private Message       Edit/Delete Post 
What he said!

 |  IP: Logged

David Buckley
Jedi Master Film Handler

Posts: 525
From: Oxford, N. Canterbury, New Zealand
Registered: Aug 2004


 - posted 09-23-2015 08:39 PM      Profile for David Buckley   Author's Homepage   Email David Buckley   Send New Private Message       Edit/Delete Post 
This seemed so obvious that it cant possibly be the case, but reading the thread three times, I may have a slightly different understanding.

Perhaps the issues is that this is a host-to-lan VPN, and thus at the host end (ie at home) there is only one IP address, and thus the choice of what to connect to at the far end is made by what port one connects to at the local end, through a mapping table.

In such a case, in every router I've needed to configure, it is possible to set both the source port and the destination port independently, even though they are usually set the same.

In the image below, which is a SSH VPN configuration, there are two VNC connections to different hosts, named Library and Rack, both on port 5900, but at the local end they are on different ports (5902 and 5903) on the same local IP address, which isn't shown.

 -

 |  IP: Logged

Marco Giustini
Film God

Posts: 2713
From: Reading, UK
Registered: Nov 2007


 - posted 09-24-2015 04:38 AM      Profile for Marco Giustini   Email Marco Giustini   Send New Private Message       Edit/Delete Post 
Leo,

The description you give us

quote: Leo Enticknap
It's on a VPN, which has been set up such that when you connect to the VPN, it's as if you are plugged directly into the router in the booth
qualifies your VPN as any VPN I've encountered. If it works locally when you're plugged into the router, why shouldn't it work remotely?

 |  IP: Logged

Leo Enticknap
Film God

Posts: 7474
From: Loma Linda, CA
Registered: Jul 2000


 - posted 09-27-2015 06:43 PM      Profile for Leo Enticknap   Author's Homepage   Email Leo Enticknap   Send New Private Message       Edit/Delete Post 
Apologies for the delayed response - a busy few days.

The problem is that I don't have control over the router through which the connection comes into the building from the outside world. The booth router is downstream of that, and our IT guy has set the "outside world" router up such that when I log on to the VPN, I then have one internal IP address that takes me to the booth router. I've just checked the settings of the booth router (Netgear FVG318) and there doesn't seem to be any way in the port forwarding page to say "Please direct an incoming connection on port 5901 to 192.268.40.30:5900" (or whatever address). There probably are routers out there that can do that, and so the solution to this may be a new router.

 |  IP: Logged

Frank Cox
Film God

Posts: 2234
From: Melville Saskatchewan Canada
Registered: Apr 2011


 - posted 09-27-2015 07:03 PM      Profile for Frank Cox   Author's Homepage   Email Frank Cox   Send New Private Message       Edit/Delete Post 
The router that you have can do it, no need to change it.

Inbound Rules (Port Forwarding)

 |  IP: Logged

Scott Norwood
Film God

Posts: 8146
From: Boston, MA. USA (1774.21 miles northeast of Dallas)
Registered: Jun 99


 - posted 09-28-2015 12:19 AM      Profile for Scott Norwood   Author's Homepage   Email Scott Norwood   Send New Private Message       Edit/Delete Post 
A cursory review of that page does not show a way to redirect to a different port on the inside machine.

On a Cisco router (the real ones, not the "Cisco Small Business" ones), the command that you want is this, assuming that your inside host is 10.1.1.3 and your external address is 172.24.1.2:

ip nat inside source static tcp 10.1.1.3 5900 172.24.1.2 5900 extendable

This re-directs port 5900 on the outside address to port 5900 on 10.1.1.3. You can change either port numbers as necessary to re-direct from an arbitrary number to a different arbitrary number, including re-directing multiple external ports to port 5900 on multiple internal hosts.

This is not esoteric or difficult stuff, so maybe a firmware update for the Netger box would include support for doing this.

 |  IP: Logged

Leo Enticknap
Film God

Posts: 7474
From: Loma Linda, CA
Registered: Jul 2000


 - posted 09-28-2015 12:57 AM      Profile for Leo Enticknap   Author's Homepage   Email Leo Enticknap   Send New Private Message       Edit/Delete Post 
Thanks Scott - I can't see any way of doing this with this model of router, either. It can forward a given incoming port to a given local IP, but only on the same port. It's running the latest firmware version. It looks like a new router if this is going to be made to work.

 |  IP: Logged

Frank Cox
Film God

Posts: 2234
From: Melville Saskatchewan Canada
Registered: Apr 2011


 - posted 09-28-2015 02:29 AM      Profile for Frank Cox   Author's Homepage   Email Frank Cox   Send New Private Message       Edit/Delete Post 
another web page about this router

 -

It appears that the setting for port translation is under LAN WAN RULES on that router. Note the checkbox for "Translate to port number"

 |  IP: Logged

Marco Giustini
Film God

Posts: 2713
From: Reading, UK
Registered: Nov 2007


 - posted 09-28-2015 02:30 PM      Profile for Marco Giustini   Email Marco Giustini   Send New Private Message       Edit/Delete Post 
If you VPN on that router, you're not on the WAN anymore, you land on the LAN and you won't need any port forwarding.

Any chance that you're not actually using VPN but you're simply dialling an external ip which takes you to ONE device?

 |  IP: Logged

Steve Guttag
We forgot the crackers Gromit!!!

Posts: 12814
From: Annapolis, MD
Registered: Dec 1999


 - posted 09-28-2015 02:53 PM      Profile for Steve Guttag   Email Steve Guttag   Send New Private Message       Edit/Delete Post 
If I read it right...he is saying that he is VPNing to ITs router which gets him to the WAN side of HIS router and that his router does not have any direct internet access. So...what he is getting to is not his network except any port forwards he puts on his WAN side.

A rather cumbersome way to be...each device would have to have a separate port number so you could access them all. Seriously, you should consider putting a cheap computer on YOUR network and just remote into that. A side benefit, if you are doing any transfers/updates...etc...and there is internet trouble, you never affect a live server.

 |  IP: Logged

David Buckley
Jedi Master Film Handler

Posts: 525
From: Oxford, N. Canterbury, New Zealand
Registered: Aug 2004


 - posted 09-28-2015 06:34 PM      Profile for David Buckley   Author's Homepage   Email David Buckley   Send New Private Message       Edit/Delete Post 
This is not an unusual setup at all, either with or without a VPN, particularly when one finds oneself in a situation where one does not have control of the equipment.

quote: Leo Enticknap
... our IT guy has set the "outside world" router up such that when I log on to the VPN, I then have one internal IP address that takes me to the booth router.
So from the perspective of the gear inside the booth, there is a single router to the outside world, pretty much the same as a home DSL. The VPN gets Leo to the one IP address that his booth exposes. So what needs to be set up on the booth router is an inbound connection with port forwarding, which is on page 4-6 of the manual, and Frank has posted a screenshot from the manual which is the exact screen necessary to set this up.

The only wiggle is that you will need to add a pair of custom services, one for each destination, manual, page 4-12. When you set up the service, make the start and end ports the same, they are the port you will connect to from the remote connection.

 -

Once you've set up the services, you can then set up a port forward to connect each service to the two VNC targets.

 |  IP: Logged



All times are Central (GMT -6:00)  
   Close Topic    Move Topic    Delete Topic    next oldest topic   next newest topic
 - Printer-friendly view of this topic
Hop To:



Powered by Infopop Corporation
UBB.classicTM 6.3.1.2

The Film-Tech Forums are designed for various members related to the cinema industry to express their opinions, viewpoints and testimonials on various products, services and events based upon speculation, personal knowledge and factual information through use, therefore all views represented here allow no liability upon the publishers of this web site and the owners of said views assume no liability for any ill will resulting from these postings. The posts made here are for educational as well as entertainment purposes and as such anyone viewing this portion of the website must accept these views as statements of the author of that opinion and agrees to release the authors from any and all liability.

© 1999-2020 Film-Tech Cinema Systems, LLC. All rights reserved.