Cisco Catalyst 3120 Command Reference Manual page 499

Chapter 2 Cisco Catalyst Blade Switch 3120 for HP Cisco IOS Commands
Table 2-26
Table 2-26
DHCP Snooping Statistic
Packets Processed by DHCP Snooping
Packets Dropped Because IDB not known
Queue full
Interface is in errdisabled
Rate limit exceeded
Received on untrusted ports
Nonzero giaddr
Source mac not equal to chaddr
Binding mismatch
OL-12248-01
shows the DHCP snooping statistics and their descriptions:
DHCP Snooping Statistics
Description
Total number of packets handled by DHCP
snooping, including forwarded and dropped
packets.
Number of errors when the input interface of the
packet cannot be determined.
Number of errors when an internal queue used to
process the packets is full. This might happen if
DHCP packets are received at an excessively high
rate and rate limiting is not enabled on the ingress
ports.
Number of times a packet was received on a port
that has been marked as error disabled. This might
happen if packets are in the processing queue
when a port is put into the error-disabled state and
those packets are subsequently processed.
Number of times the rate limit configured on the
port was exceeded and the interface was put into
the error-disabled state.
Number of times a DHCP server packet (OFFER,
ACK, NAK, or LEASEQUERY) was received on
an untrusted port and was dropped.
Number of times the relay agent address field
(giaddr) in the DHCP packet received on an
untrusted port was not zero, or the no ip dhcp
snooping information option allow-untrusted
global configuration command is not configured
and a packet received on an untrusted port
contained option-82 data.
Number of times the client MAC address field of
the DHCP packet (chaddr) does not match the
packet source MAC address and the ip dhcp
snooping verify mac-address global
configuration command is configured.
Number of times a RELEASE or DECLINE
packet was received on a port that is different than
the port in the binding for that MAC
address-VLAN pair. This indicates someone
might be trying to spoof the real client, or it could
mean that the client has moved to another port on
the switch and issued a RELEASE or DECLINE.
The MAC address is taken from the chaddr field
of the DHCP packet, not the source MAC address
in the Ethernet header.
Cisco Catalyst Blade Switch 3120 for HP Command Reference
show ip dhcp snooping statistics
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