It is possible under certain conditions. Without going into a fully 802.11 explanation, Devices on a network do not actually communicate using the IP Address, The IP is linked to the MAC address of the device using APR Tables.

If the APR and IP have got out of sync, then it will not work. It is possible to manually assign an IP to an MAC.

You can see the ARP Table by typing: "ARP -a" at the CMD prompt. some router will show you the ARP table in the GUI, most will display address if it has access by Telnet or SSH.

It sound like the problem is between PC and NVR, so check the PC ARP table against the MAC set in the NVR.

The simplest thing to do is flush the APR Cache using: "netsh interface ip delete arpcache" in an elevated CMD prompt.

This will not damage anything, it just causes the cache to rebuild.

Hope this help.

#SentryAlertSystems

Reading your post again, have you allowed the NVR to obtain an IP by DHCP and then Hardcoded that address as STATIC in the NVR? This is a complete NO.NO.. And will cause Hell.

Address allocated by DHCP come from a DHCP pool, this is managed by the router. Once you switch the NVR to Static, the DHCP will re-allocate this IP to the next device needing an address by DHCP. Now you have two devices with the same IP address. And this with most definitely caused APR problems. When a systems needs to find a device for the first time, it sends a 'whois' broadcast, both devices will respond with there MAC. the PC only has space for one MAC.

You must allocate a Static IP from outside of the DHCP Pool. This will be a setting in the router with the DHCP Start Address and Size. So if it starts at 192.168.1.50 and size of 50, use an address below 192.168.1.50 or above 192.168.1.100.

i.e. 192.168.1.49 or 192.168.1.101.

Please let me know if this helps?

When doing it via dhcp then making the dvr static there is normally a reverse option in the router?

Me being a numpty would have thought the router wouldn't hand this out again as its been reserved in its settings?

on most I put it outside the table , but curious about the above?

The router will reserve the IP Address for the period of the lease time. Some route will let you set the lease time, but its normal between 1 to 3 days. But could be hours. You can see the lease time on a PC by typing: ipconfig /all under the CMD prompt. Look for Lease Expires

If this reserved it forever, it would not the Dynamic. And eventual, all the IP will be used up.