Planet GS-5220 Series, User Manual, Page: 440 / 568

User’s Manual of GS-5220 LCD Series
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• Age/Hold

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.
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.