From Newsgroup: uk.comp.homebuilt


My new TP-Net Omada DR3650v-4G router appears to have a bit more
functionality than the Plusnet Modem 2.

One is the ability to reserve IP addresses by MAC. In terms of performance
is there likely to be a difference between allocating fixed IP addresses
to my key PCs and the NAS and using DHCP with a reserved address?
--
Jeff Gaines Dorset UK
This is as bad as it can get, but don't bet on it
--- Synchronet 3.22a-Linux NewsLink 1.2

From Newsgroup: uk.comp.homebuilt

Jeff Gaines wrote:

the ability to reserve IP addresses by MAC. In terms of performance is
there likely to be a difference between allocating fixed IP addresses to
my key PCs and the NAS and using DHCP with a reserved address?

None whatsoever.

--- Synchronet 3.22a-Linux NewsLink 1.2

From Newsgroup: uk.comp.homebuilt

On 11/06/2026 17:28, Jeff Gaines wrote:

My new TP-Net Omada DR3650v-4G router appears to have a bit more functionality than the Plusnet Modem 2.

One is the ability to reserve IP addresses by MAC. In terms of
performance is there likely to be a difference between allocating fixed
IP addresses to my key PCs and the NAS and using DHCP with a reserved address?

I use static IPs on devices that I need to access from outside the
house, so that's my house alarm, CCTV, NASes, DNS, Wireguard, OpenVPN
and the main router.

if I have dynamic IP on teh above devices, the various apps on my phone
and tablets get confused quickly!

--- Synchronet 3.22a-Linux NewsLink 1.2

From Newsgroup: uk.comp.homebuilt

On 11/06/2026 19:32, SH wrote:

On 11/06/2026 17:28, Jeff Gaines wrote:

My new TP-Net Omada DR3650v-4G router appears to have a bit more
functionality than the Plusnet Modem 2.

One is the ability to reserve IP addresses by MAC. In terms of
performance is there likely to be a difference between allocating
fixed IP addresses to my key PCs and the NAS and using DHCP with a
reserved address?

I use static IPs on devices that I need to access from outside the
house, so that's my house alarm, CCTV, NASes, DNS, Wireguard, OpenVPN
and the main router.

if I have dynamic IP on teh above devices, the various apps on my phone
and tablets get confused quickly!

its because some devices do not allow the entering of a host name and/or
the app won't let you enter the host name so entering local host names
to my hosts files on the two DNS does not work.... :-(
--- Synchronet 3.22a-Linux NewsLink 1.2

From Newsgroup: uk.comp.homebuilt

Jeff Gaines wrote:

My new TP-Net Omada DR3650v-4G router appears to have a bit more functionality than the Plusnet Modem 2.

One is the ability to reserve IP addresses by MAC. In terms of
performance is there likely to be a difference between allocating fixed
IP addresses to my key PCs and the NAS and using DHCP with a reserved address?

In a domestic environment, generally none whatever.

Problems may arise in a commercial environment where there is a server managing DHCP and DNS; and UPS to ensure the server shuts down cleanly
when there is a power failure.

It follows that when the power returns, the UPS must recharge its
batteries, then will tell the server to start. Even it this is quick
the server itself will not start its DHCP and DNS services immediately -
it could be several minutes.

Now consider what happens to devices such as printers, NASes, security cameras, etc. When power returns they all start quickly and broadcast
for a DHCP server - and of course they get no reply. So they might autoconfigure (an address like 169.254.x.y) or not give themselves an IP address at all. So the users can't print and complain bitterly!.

If these devices are all configured with static IP address (so far as is possible) then that helps, but it's not the end of the problem.

Suppose the printer is out of commission - powered off for a good
reason. The DHCP server might issue the address configured in the
printer to another device. When the printer is powered on again, it
reports an address clash with the other device. So the DHCP service
must be configured with a "reserved" address so that it does not issue
such addresses to any other requester.

In a domestic environment the router will (probably) start quickly when
mains power is restored. But the NAS, printer, security cameras etc
might start equally quickly - so you could theoretically see problems.

The resolution is to allocate a range of address (a scope) in the
router's DHCP service, and to configure reserved (bound, or other
similar term) addresses outside the scope, to the devices that must be
static. Then configure these devices with those same reserved
addresses. So KEEP DOCUMENTATION!

Not all routers give you this flexibility, and not all devices can be
manually configured correctly. It's important to specify the default
gateway so such devices can contact the internet for time services or
updates.
--
Graham J
--- Synchronet 3.22a-Linux NewsLink 1.2