Edge-Core ECS4660-28F Management Manual page 1136

| General Security Measures
C 29
HAPTER
IPv4 Source Guard
Setting source guard mode to "sip" or "sip-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. Use the no ip source guard command to disable
this function on the selected port.
When enabled, traffic is filtered based upon dynamic entries learned via
◆
DHCP snooping, or static addresses configured in the source guard
binding table.
Table entries include a MAC address, IP address, lease time, entry type
◆
(Static-IP-SG-Binding, Dynamic-DHCP-Binding, VLAN identifier, and
port identifier.
◆ Static addresses entered in the source guard binding table with the
source-guard binding
infinite lease time. Dynamic entries learned via DHCP snooping are
configured by the DHCP server itself.
If the 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 DHCPv4 snooping is disabled (see
■
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, the packet will be forwarded.
If the 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 (dynamically learned via DHCP snooping or manually
configured) are not yet configured, the switch will drop all IP traffic
on that port, except for DHCP packets.
Only unicast addresses are accepted for static bindings.
■
E
XAMPLE
This example enables IP source guard on port 5.
Console(config)#interface ethernet 1/5
Console(config-if)#ip source-guard sip
Console(config-if)#
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command are automatically configured with an
page
ip
1116), IP source guard