My PC “bit the dust” a few weeks ago and I am trying to ensure that I will be able to connect the new one on order to the same IP (keeping all object names, labels, comments etc as unchanged as possible). The old IP was static outside the DHCP range. Set up using Bind IP to Mac. The broken PC has not been connected for weeks now: hence it there is unlikely to be any issue with any refresh, cache life etc. To avoid a possible conflict where new PC would obviously have new MAC address but retain same IP I have been trying to delete the the ARP cache and bind list for this single entity.Through the GUI the entry will delete from the bind list ONLY and then temporarily ONLY: I can only presume it is reading from the cache? It also reappears in the ARP after a delete and refresh: how can this be when the device and IP are no longer on the network? So....I tried the CLI....using ip arp del 192.168.x.x.....and that did nothing! I don’t want to “clear/flush” the entire cache for fear of the extra work reestablishing bindings etc when all other devices and entries are good. It can’t be this difficult to delete one entry from these tables surely, where am I going wrong? Or would connecting new PC under same IP proceed without issue and auto refresh some of these entries i.e am I over-thinking it?

Are you saying you want to add the MAC address of the new PC to the "Bind List", but it won't let you (or lets you, but continues to issue an address from the DHCP pool)?

If so, issue a "Ipconfig /release" command (or unplug your PC lan and reboot the router). Then using a different device, add the new MAC address to "Bind IP to MAC".

A variation on this theme, would be to temporarily set your PC to use a static address, if you don't have a suitable second device.

Alternatively, you could set the MAC address of your new PCs LAN adapter to be the same as your old one - this will be described as "Network Address", or "Physical Address" in the advanced options of the adapter config. (Just found you a 'guide': https://www.digitalcitizen.life/change-mac-address-windows/ )

Don't worry about the ARP cache - you can flush it as much as you like, it's got nothing to do with DHCP.

I don’t have the new PC yet. I am “preparing the ground” for it. What I want to do is to use the same IP as the old PC. I would like to retain/keep the same as much information In the router as possible I.e. I will bind this IP to MAC address. I was not aware the MAC address of new PC could be changed to match the old one: that might solve some of or all of the issues I am foreseeing. The IP and new PC will have a static address(same one fixed IP I am talking about . Not DHCP). I don’t understand your comment about the ARP cache: NONE of the addresses in there are part of the DHCP pool, intentionally so, they are static/fixed outside pool range,as is the IP/MAC detail of old PC.....hence my concern of a conflict if I use same IP but with different MAC and router uses cached information.Ipconfig/release is not relevant, except perhaps, when I have new PC and need to clear initial setup address to start adding fixed IP etc.....this part of confusion I mentioned...why when PC no longer exists on network ...are both ARP and ARP cache retaining it and I cannot delete the entry’s using highlight and delete options in Bind IP to MAC form?

Forgive me if I am misunderstanding here but it seems to me that you are creating a problem for yourself that doesn't exist. I use IP-MAC binding extensively. If I remove a device from the network but want to use its IP address for a new device I simply delete the entry from the IP bind table, connect the new device and let it be given a DHCP address, add that address to the table and edit it so that it becomes the "old" static IP address that I want to use. Seems to work OK for me. Have I misunderstood?

Slightly misunderstanding :wink: ”simply delete the entry from the bind table”: exactly!!!! Using highlighting/selecting entry then delete button then refresh. The entry does not permanently disappear. It reappears in ARP table despite not being on network for weeks. Hence my admittedly non-expert theory that something is being drawn in from the ARP cache.

I should also add that the device lies outside my DHCP pool range and I am therefore not being confused by the releasing of the old IP and potential issuing to another device...