Resolving FOSCAM connection dropouts

I bought a FOSCAM FI8908W wireless IP webcam off eBay recently. It has lots of features for the price.

However, I've had problems with being unable to connect to the camera after a period of time (an hour or so). Power cycling the camera would fix the problem.

I've tried upgrading to the latest firmware (version 11.14.2.17 is supposed to fix WiFi disconnection problems), but it did not fix my problem.

Problem analysis

The problem is not related to my browser or the wireless network. I've tried disabling DHCP (router based static IP). It turns out the problem is that the webcam simply ceases to respond to ARP (Address Resolution Protocol) requests (once in this broken state).

ARP is a mechanism to translate between IP addresses and device MAC addresses. It underpins all IP communications over both Ethernet and WiFi, since at the lowest level it relies on exchange of packets between device MAC addresses. The ARP protocol allows a network device to discover the MAC addresses of the peer device with the designated IP address, therefore allowing communication.

When the IP webcam stops responding to ARP requests, you're in a situation where your client (PC/NAS etc) says "who has this IP?" and simply gets no response.

A static ARP entry is a fixed mapping between an IP address and the device MAC address.  In this case you never need to ask "who has this IP?", because it is known in advance.  Instead, the IP to MAC translation is successfully performed and the request packet sent to the destination.

TIP: A static ARP entry must not be confused with a static DHCP lease.  A static DHCP lease means the device is granted a fixed/static IP by your modem/router (based on its MAC address).  However clients will still lose communication with the device once it ceases to respond to ARP requests.  The modem/router cannot respond to ARP requests sent to the IP webcam, the IP webcam must respond to these.

Where to fix

Fixing the problem needs to be done on all devices that will communicate with the IP webcam.  If you simply do so from the family PC, or laptop then you need to apply the fix there.

If you have a NAS (Network Attached Storage) device that records from the IP webcam then you need to apply the fix on the NAS itself.

If you make the IP webcam directly accessible via the Internet, then the change would need to be applied to your modem/router.

Prerequisites

Assign static IP address

Since we'll use a fixed mapping from IP address to MAC address, you will need to use a fixed IP address for your IP webcam.  This is referred to as a static IP address.  The IP address is normally configured in the IP webcam settings, though you can get fancy and get your router (DHCP server) to always assign the same IP address.  Make sure the IP address is not in the range that might be assigned to other devices.

To identify the configured IP address range used by DHCP, you will need to refer to your modem/router.  For example this device is using the range 192.168.1.1 to 192.168.1.100 to dynamically assign to devices.  Therefore you could allocate a static IP of 192.168.1.200.

Determine MAC address

You need to know the MAC address of your IP webcam.  This is normally printed on the device itself, and will be in the form AA:BB:CC:DD:EE:FF, or AA-BB-CC-DD-EE-FF.  Note that each network interface has a different MAC address - so there will be one for the WiFi network, and one for the Ethernet network.  Make sure you choose the correct one.

If you cannot access the IP webcam easily, then instead you can determine the MAC address from your PC.  Reboot your IP webcam so that it will be accessible.  Then open a terminal or Command Prompt window, and run these commands.  Note these commands should be the same/similar across Windows, MAC or Linux.

Verify you have connectivity to the IP address of your IP webcam:

c:\> ping 192.168.1.20

Pinging 192.168.1.20 with 32 bytes of data:

Reply from 192.168.1.20: bytes=32 time=7ms TTL=64
Reply from 192.168.1.20: bytes=32 time=3ms TTL=64
Reply from 192.168.1.20: bytes=32 time=3ms TTL=64
Reply from 192.168.1.20: bytes=32 time=3ms TTL=64

Ping statistics for 192.168.1.20:
Packets: Sent = 4, Received = 4, Lost = 0 (0% loss),
Approximate round trip times in milli-seconds:
Minimum = 3ms, Maximum = 7ms, Average = 4ms

Then display the known IP addresses and MAC addresses.  Take note of the MAC address corresponding to the IP address of your IP webcam.

c:\> arp -a
...
Internet Address   Physical Address    Type
192.168.1.20       01-12-23-34-45-56   dynamic

Solution

Solution for Windows XP

These are the commands for Windows prior to Windows 7.

Add:

c:\> arp -s 192.168.1.20 01-12-23-34-45-56

View:

c:\> arp -a
...
Internet Address   Physical Address    Type
192.168.1.20       01-12-23-34-45-56   dynamic

Delete (if you need to revert the change):

c:\> arp -d 192.168.1.20

To make this change persist after rebooting, simply add the "arp -s" command to a batch file that you run from your Windows startup folder.

Solution for Windows 7 and Windows 10

Note that adding & removing static ARP entries must be done using an Administrator Command Prompt.

Add:

C:\WINDOWS\system32> netsh interface ipv4 add neighbors "Local Area Connection" store-persistent 192.168.1.20 01-12-23-34-45-56

View:

C:\WINDOWS\system32> arp -a
...
Internet Address   Physical Address    Type
192.168.1.20       01-12-23-34-45-56   dynamic

Delete (if you need to revert the change):

C:\WINDOWS\system32> netsh interface ipv4 delete neighbors name="Local Area Connection" 192.168.1.20

Unix (NAS, and possibly MAC)

These commands have been tested on a Synology NAS.

Add:

# arp -s 192.168.1.20 01:12:23:34:45:56

View:

# arp -a
...
? (192.168.1.20) at 01:12:23:34:45:56 [ether] PERM on eth0

Delete (if you need to revert the change):

# arp -d 192.168.1.20

You need to run the arp command when your NAS boots.  On a Synology NAS you would use the Task Scheduler.  Otherwise for other brands you may need to create an init script, or cron job instead.

Modem/Router

I strongly recommend against letting your IP webcam be accessed directly from the Internet.  Specifically you should not be relying on the security of your IP webcam.  There could be a security flaw which mean that the IP webcam is (a) allowing strangers to access the video feed, or (b) providing a back-door into your home network.

A much better way is to get a quality router or NAS with VPN server functionality.  From the Internet you can then establish a secure VPN between your laptop/smartphone and your home network. Once the VPN is connected, then you can access the IP webcam just like when you're at home.

However, if you wish to proceed...

The commands are likely to be different for every brand of modem/router.  It may be impossible to configure on many brands or models.

These commands work on an older Billion modem (7404VGO-M).

Add:

C:> telnet router_ip
admin> ip interface iplan add staticarpentry 192.168.1.20 01:12:23:34:45:56

View

C:> telnet router_ip
admin> ip interface iplan list staticarpentries

Static ARP entries for interface: iplan

ID   | IP Address      | MAC Address
-----|-----------------|-------------------
1    | 192.168.1.20    | 01:12:23:34:45:56
-------------------------------------------

Smartphone

It is only likely to be possible if you have a rooted mobile.
I suggest you get a NAS with built-in capability of recording and storing video from your IP webcam.  Then, use the apps provided by your NAS manufacturer to access access live view and recordings.