Why Does XB8 Gateway Assign Dynamic IP addys not really in order

computerman2

Hello There

Some reason my network devices i’ve noticed start out at .1, .48, .94, .116 and go from up there. Like my Wifi HP Printer is .130

Shouldn’t it be .1,2,3. 4 etc?

Guess not something to really worry on…til sometime i update the Wifi password again, and maybe then it will fix itself possibly

HardlyWorthit

computerman2
If it aint broken, don’t fix it.

MacLeech

computerman2 It’s a security through obscurity move.

It’s a bit more difficult to tell how many devices are on the network if 10 are randomly scattered across a scope of 254 vs those 10 being in sequential order.

Also, many newer Wi-Fi devices use “Wi-Fi Privacy” by changing MAC addresses between Wi-Fi network connections to force different IP assignments and reduce tracking attempts.

CommunityMember

computerman2 Shouldn’t it be .1,2,3. 4 etc?

At least one well known (and commonly used) dhcp server in the embedded space assigns (by default) a pseudo-random IP (hashed from the MAC address) from its available ranges, if there is not an existing assignment for that device. One advantage of doing so (using the hash) is that even if the device lease has long ago expired (powered off or disconnected) there is an increased chance that the IP it had used previously can be reassigned to the same device when it becomes active again. While the build/config for that server can override the defaults (and assign addresses sequentially), there is little reason to do so.

jweaver

All Xfinity gateways do that. It would also seem the IPv4 addresses assigned by DHCP are a bit more sticky compared to other routers.

computerman2

Oh ok, well then will stop worrying on this aspect of things then.

Just concerned me a little, but now i understand why it does what it does, and leaves it alone

Andyross

I have an Asus router, and DHCP also seems a bit random.

Devious

All you have to do with Asus router is manually assign the IP (LAN > DHCP Server) and the client will always have the same IP assigned by the router. You can also set the hostname for the device.
I also limit the IP ending pool to how many clients I have then nothing else can connect as no IP to obtain.

Andyross

As far as I can tell, once assigned to a MAC, it seems to never change. It’s just that initial assignment that is random.

jweaver

Andyross It seems to either go by its logic to reassign IP and sees the IP as available when device reconnects or it may be retaining it’s IP Assignment table even beyond reboot, granted device has been online with DHCP Lease renewal.