Dhcp Snooping - Planet GS-5220 Series User Manual

• Age/Hold

4.12.8 DHCP Snooping

DHCP Snooping is used to block intruder on the untrusted ports of DUT when it tries to intervene by injecting a
bogus DHCP reply packet to a legitimate conversation between the DHCP client and server.
If at least one user module has decided to block this MAC address,

it will stay in the blocked state until the hold time (measured in
seconds) expires.
If all user modules have decided to allow this MAC address to

forward, and aging is enabled, the Port Security module will
periodically check that this MAC address still forwards traffic.
If the age period (measured in seconds) expires and no frames

have been seen, the MAC address will be removed from the MAC
table. Otherwise a new age period will begin.
If aging is disabled or a user module has decided to hold the MAC

address indefinitely, a dash (-) will be shown.
440
User's Manual of GS-5220 LCD Series