Super User is a question and answer site for computer enthusiasts and power users. Join them; it only takes a minute:

Sign up
Here's how it works:
  1. Anybody can ask a question
  2. Anybody can answer
  3. The best answers are voted up and rise to the top

I have three IP cameras installed on my LAN and I am accessing all of those on the same LAN using Internet Explorer. How can I access any of these cameras from another LAN? Each camera is set up with the gateway as and I am able to access any camera by 192.168.1.(3 or 4 or 5) but this URL is not working when I try from another LAN.

share|improve this question

migrated from Jul 19 '11 at 12:26

This question came from our site for professional and enthusiast programmers.

Sure because the other network doesnt know the cameras. You need to connect the networks using vpn (for example) or bring the cameras to the internet (using dyndns or a ip).

This is a administration thing...

share|improve this answer

192.168.* is a private address family intended for internal, private LAN usage. This is a defined feature of the TCP/IP addressing standards. What this means is that routers and gateways will not route or forward any packets for 192.168 address outside of the local network.

This has nothing to do with Java, it's a purely network thing. Like someone already suggested, you need to set up a NAT gateway. Most OTC LAN or broadband routers intended for home-usage have NAT capability so likely you have it already. All you need to do is create mappings to connect the address and ports of your webcams to ports that are then accessible from your public IP. I would consult the manual of your LAN router if you are unsure about how this works.

If your public IP is DHCP assigned (like most are on public ISP subscriptions), you might want to look into one of the dynamic DNS services out there (like so you can access your home IP using a DNS name rather than the IP.

share|improve this answer
Routers will route anything that is outside the LAN. What is outside is determined by the subnet mask. You should use LAN addresses with 192.168.x.y and usually you use as subnet mask for a home LAN. Then, anything ouside 192.168.x will be routed outside the LAN. This must be configured in the network settings, but no router will route or not route traffic outside the LAN just because of the IP-address range 192.168.x.y. – Martin Jul 19 '11 at 14:55

This is a routing issue. The computers on the "other" network do not know how to get to 192.168.1.x What you need to do is make sure that the router that the computers on the other network knows how to reach the device which is

(This is a routing principle that isn't obvious: just because I can get a packet to you doesn't implicitly mean you can get a packet back to me.)

share|improve this answer

Well I could go on an explain it all but instead it might be good idea to read this about routing. Found it the other day, its a good read and explains how routing works. It will answer your questions and allow you to do it yourself in future

share|improve this answer

You have to setup NAT on your router. Then you can access these cameras with your public IP and a port.

share|improve this answer

You must log in to answer this question.