C
U
OMMAND
SAGE
◆
Setting source guard mode to SIP (Source IP) or SIP-MAC (Source IP
and MAC) enables this function on the selected port. Use the SIP option
to check the VLAN ID, source IP address, and port number against all
entries in the binding table. Use the SIP-MAC option to check these
same parameters, plus the source MAC address. If no matching entry is
found, the packet is dropped.
Multicast addresses cannot be used by IP Source Guard.
N
:
OTE
When enabled, traffic is filtered based upon dynamic entries learned via
◆
DHCP snooping (see
addresses configured in the source guard binding table.
If IP source guard is enabled, an inbound packet's IP address (SIP
◆
option) or both its IP address and corresponding MAC address (SIP-
MAC option) will be checked against the binding table. If no matching
entry is found, the packet will be dropped.
Filtering rules are implemented as follows:
◆
If DHCP snooping is disabled (see
■
check the VLAN ID, source IP address, port number, and source
MAC address (for the SIP-MAC option). If a matching entry is found
in the binding table and the entry type is static IP source guard
binding, the packet will be forwarded.
If DHCP snooping is enabled, IP source guard will check the VLAN
■
ID, source IP address, port number, and source MAC address (for
the SIP-MAC option). If a matching entry is found in the binding
table and the entry type is static IP source guard binding, or
dynamic DHCP snooping binding, the packet will be forwarded.
If IP source guard if enabled on an interface for which IP source
■
bindings have not yet been configured (neither by static
configuration in the IP source guard binding table nor dynamically
learned from DHCP snooping), the switch will drop all IP traffic on
that port, except for DHCP packets.
P
ARAMETERS
These parameters are displayed:
Filter Type – Configures the switch to filter inbound traffic based
◆
source IP address, or source IP address and corresponding MAC
address. (Default: None)
None – Disables IP source guard filtering on the port.
■
SIP – Enables traffic filtering based on IP addresses stored in the
■
binding table.
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C
HAPTER
"DHCP Snooping" on page
page
358), IP source guard will
| Security Measures
14
IP Source Guard
355), or static