networking - Why is my D-Link IP webcam unreachable from within the LAN, but accessible from outside?

06
2014-04
  • abaumg

    I recently bought a D-Link DCS-930L network webcam which is connected to my WLAN network. It retrieves a IP address via DHCP from DD-WRT based router (a TP-Link TL-WR1043ND), and it is listed under "Active wireless nodes".

    The camera is registered to a webservice called "My DLink", which enables the user to access the webcam from the internet (via their webpage or via smartphone apps). This service works, and I can access the camera from outside.

    However, when I try to connect from inside my (W)LAN, it says "No route to host". How is that possible?

    --

    EDIT: I found the answer by myself accidentally by skimming through the IP webcam settings. It turned out that the option Setup > Network Setup > UPnP Port Forwarding was set to Enable. I don't use UPnP in my LAN, and it is disabled on my router.

    I don't understand how the enabled UPnP on the webcam could cause troubles, when there were no other devices supporting UPnP. Has anybody an explanation for this?

    • Answers
  • MariusMatutiae

    Most of all, you have a very confused routing table. You may wish to erase all of your routes, and let eth0 acquire a new address via DHCP: Then I bet you will see your camera. In other words: I believe the problem lies with your routing table, not with your camera.

    Try the follwoing: as sudo, 

       service network-manager stop
   ifconfig br0 down
   brctl delbr br0 
   ifconfig eth0 down
   ifconfig eth0 up 
   dhclient eth0
   ping -c3 192.168.1.30

    I think it will work now. In any case, all of the changes above disappear upon reboot.

  • user295510

    It's possible that you turned on ap isolation in the basic wireless settings of dd-wrt.


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  • Chris Marisic

    Recently I upgraded to Comcast Business and their modem has a built-in router so I took off my DD-WRT router and moved to a location in my home where I needed more ports and Wi-Fi (preferably without running new Ethernet cables since it's 50-100 foot run through floor and ceilings).

    I have my network cable from my Comcast modem going into Port 1 of my DD-WRT router with Port 2 and 3 being networked PCs. I have DD-WRT setup as a DHCP forwarder with the firewall disabled. This lets my all of my devices access the network fine. Is the correct the way to do this? Or is this a less optimal solution and it should be done in a slightly different way?


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  • Peter Mortensen

    If you're OK with the Comcast modem's firewalling capabilities then that sounds fine. If it were my network, I would disable the modem's routing and do all the NAT'ing on the DD-WRT router because I'm picky about my firewall rules.