NVR configuration
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FortiRecorder 2.4.2 Administration Guide
5.
If you want to fine-tune the behavior, configure these settings:
Setting name
Description
Conflicted IP
timeout (Seconds)
Type the maximum amount of time that the DHCP server will wait for
an ICMP
ECHO
(ping) response from an IP before it determines that it
is not used, and therefore safe to allocate to a DHCP client that is
requesting an IP address. The default is 1,800 seconds (3 minutes).
To ensure that the DHCP server does not cause IP address conflicts
with misconfigured computers that are accidentally using the pool of
IP addresses used for DHCP, when a client request a new DHCP
lease, the built-in DHCP server will ping an unused IP address in the
pool first. If the ping test is successful, then a misconfigured
computer is currently using that IP, and allocating it also to the DHCP
client would cause an IP address conflict. To prevent this, the DHCP
server will temporarily abandon that IP (mark it as used by a static
host) and look for an other, available IP to give to the DHCP client. (It
will not try abandoned IPs again until the pool is exhausted.)
However, before the DHCP server can determine if the ping test is
successful, the it must first wait to see if there is any reply. This slows
down the search for an available IP address, and in rare cases, could
cause a significant delay before the DHCP client receives its
assigned IP address and other network settings. If your network is
smaller or typically has low latency to ping replies, you can safely
decrease this setting’s value to improve DHCP speed and
performance. In most cases, 3 seconds is enough.
Lease time
(Seconds)
Type the maximum amount of time that the DHCP client can use the
IP address assigned to it by the server. When the lease expires, the
DHCP client must either request a new IP address from the DHCP
server or renew its existing lease. Otherwise, the DHCP server may
attempt to assign it to the next DHCP client that requests an IP. The
default is 604,800 seconds (7 days).
If you have more or almost as many DHCP clients (cameras) as the
number of IP addresses available to give to DHCP clients, you can
decrease the lease. This will free up IP addresses from inactive
clients so that IPs are available to give to clients that are currently in
need of IP addresses. Keep in mind, however, that if the DHCP
server is attached to your overall network rather than directly to
cameras, this will slightly increase traffic volume and slightly
decrease performance.
DHCP IP Range
To configure the DHCP lease pool — the range of IP addresses that
the DHCP server can assign to its clients — click
New
and configure
the first and last IP address in the range. To avoid DHCP pool
exhaustion that can occur in some cases, the pool should be slightly
larger than the total number of clients.
If you need to exclude some IP addresses from this range (e.g.
printers permanently occupy static IPs in the middle of the range),
also configure
Tip:
The built-in DHCP server can provide IP addresses to the
computers on your network too, not just to cameras.
