DHCP Address Reservations Help
Solve IP-Related Issues
Over the last decade of custom home
installations, we have seen an explosion
in the number of products that we now
connect to a client’s home network.
A networked, connected smart TV is
now connected to cable boxes, media
streamers, and Blu-ray players–all of
which have network connections. Wholehouse
audio systems, home control
systems, and even sprinkler systems,
alarm clocks, and pianos can now have
In my home, we have 48 networkconnected
devices. An extremely
important networking concern is how a
custom integrator can best manage and
monitor all of these devices in the home
to ensure that they are running properly.
First and foremost, every device on a
home network needs an IP address to communicate with other devices on
the network and the internet. These IP addresses are typically private IP
addresses assigned by the home’s router as either a static address, which
needs to be manually assigned to a device; or a dynamic address, which is
automatically given to a device when it is first powered on.
The Static IP Address
The advantage of a static address is that you always know the address
of a device to locate or control it. The challenge of static IP addressing
is that it requires the product that receives the static IP address to have
software that supports the manual input of a given, static IP address. All
office-based network products typically support this direct input of a static
IP address, but many networkable home entertainment devices will not
allow an input of a static IP address (the Sonos music system or Boxee are
For many products, it may not matter that an IP address changes, but
in some cases it does matter. It becomes especially important when we
start to apply home networking monitoring solutions from companies like
ihiji, where one of the core strengths of their monitoring solution is to let
the integrator know if all the devices on the network are on by “pinging”
their IP addresses on a regular basis. If a Sonos player reboots and receives
a new dynamic IP address that ihiji does not recognize, it will incorrectly
diagnose that the Sonos is offline.
|DHCP address reservations are an important tool for dealing with a network crowded by IP addresses and the myriad of potential issues that presents.|
In a separate issue, we have seen a problem with some of the newer
TiVo products that when we assign a static IP address, the TiVo unit
still requests a new dynamic address over a period of time. This wreaks
havoc on our universal remote control solutions because they do not know
that the IP address of the TiVo has changed; therefore, it can no longer
be controlled when we use IP as the control communication medium (as
opposed to IR).
So what can you do to prevent these changing IP address related issues?
Use DHCP address reservations.
Applying DHCP Reservations
DHCP reservations behave just like a static IP address for a given device.
Once a product has been assigned a DHCP reservation, it will always
receive the same dynamic address.
In the previously mentioned TiVo example, the dynamic address that
was assigned to the TiVo by the router can now be paired with its MAC
address to ensure that it will always receive the same IP address. The same
dynamic address pairing can be done for the Sonos systems and all of the
other dynamically addressed networked products in the home. This level of
network address housekeeping ensures that we can monitor and manage the
IP devices in the home because they will always receive the same IP address.
Not all routers support dynamic IP address reservation, but it is my
recommendation that you only install router models that do support this
feature. To enhance the reliability of the residential home networks that
we install and improve our ability to troubleshoot and maintain them, it
is imperative that the IP addresses of the home’s network devices remain
fixed and stable. DHCP IP address reservations are one of the best tools
that we can implement to keep our clients’ home networks running
smoothly and trouble-free.