Fortinet FortiRecorder 400D, Administration Manual

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Troubleshooting Page 134 FortiRecorder 2.4.2 Administration Guide
Unauthorized DHCP clients or DHCP pool exhaustion
Typically returning DHCP clients will receive the same IP address lease. However if computers
or other devices are accidentally using IP addresses that the FortiRecorder NVR’s built-in DHCP
server should be allocating to cameras, and the pool of available DHCP IP addresses becomes
exhausted, cameras may be unable to get or retain an IP address.
To determine which devices are using your pool of DHCP IP addresses, compare the MAC
address of each device’s network adapter to the list of current DHCP clients in
Monitor >
DHCP Status > DHCP or enter this command in the CLI:
execute dhcp lease-list
Output will resemble the following:
To correct this situation, first configure unintentional DHCP clients so that they do not use
DHCP (that is, they have a static IP address) and so their IP address is not in the range used by
the DHCP pool. Second, clear the list of DHCP clients to allow legitimate DHCP clients (your
cameras) to obtain a lease:
execute dhcp clear-lease
New clients that were previously unable to get an IP address will obtain an IP address for the
first time. Returning clients’ s IP addresses may change as the built-in DHCP server no longer
has any memory of their previous lease, and may assign them a new IP address if another client
has claimed that IP address first. (This may result in temporary IP address conflicts and
therefore connectivity interruptions while the DHCP server assigns new leases.)
See also
• Configuring the DHCP server
Establishing IP sessions
If a route exists, but there appears to be a problem establishing or maintaining TCP or IP-layer
sessions between FortiRecorder and a computer or camera on your IP network, there are
multiple possible causes, such as:
• Trusted hosts
• protocols/port numbers mismatched or blocked by NAT or firewalls
• IP address conflicts
• short DHCP leases ( Lease time (Seconds) in “Configuring the DHCP server” )
• socket exhaustion
You can view a snapshot of FortiRecorder’s session table according to the IP layer. Go to
Monitor > System Status > Sessions .
port3
IP MAC-Address VCI Expiry
192.168.200.100 20:10:7a:5a:28:d1 udhcp 0.9.8 Thu Oct 4 15:01:22 2013
192.168.200.101 20:10:7a:5a:29:38 udhcp 0.9.8 Wed Oct 3 11:17:12 2013