User's Manual

User’s Manual of LRP-822CS/LRP-1622CS
249
The page includes the following fields:
Object Description
 Port
The switch port number of the logical port
 Forwarded
Display the current forwarded
 Chaddr Check Dropped
Display the chaddr check dropped
 Untrusted Port Dropped
Display untrusted port dropped
 Untrusted Port with
Option82 Dropped
Display untrusted port with option82 dropped
 Invalid Dropped
Display invalid dropped
Buttons
: Click to clear the statistics.
: Click to refresh the statistics.
verview of the DHCP Snooping Database Agent
hen DHCP
snooping is enabled, the switch uses the DHCP snooping binding database to store information about untrusted
interfaces. The database can have up to 8192 bindings.
nding) has an IP address, an associated MAC address, the lease time (in hexadecimal format), the
nterface belongs. A checksum value, the end of each entry, is
the number of bytes from the start of the file to end of the entry. Each entry is 72 bytes, followed by a space and then the
checksum value.
To keep the bindings when the switch reloads, you must use the DHCP snooping database agent. If the agent is disabled,
dynamic ARP or IP source guard is enabled, and the DHCP snooping binding database has dynamic bindings, the switch loses
its connectivity. If the agent is disabled and only DHCP snooping is enabled, the switch does not lose its connectivity, but DHCP
snooping might not prevent DCHP spoofing attacks.
The database agent stores the bindings in a file at a configured location. When reloading, the switch reads the binding file to
build the DHCP snooping binding database. The switch keeps the file current by updating it when the database changes.
When a switch learns of new bindi e entries in the database.
4.9.7.6 Database Agent
O
W
Each database entry (bi
interface to which the binding applies, and the VLAN to which the i
ngs or when it loses bindings, the switch immediately updates th