ECS4100 Series Web Management Guide-R07

Table Of Contents
Chapter 12
| Security Measures
IPv4 Source Guard
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When enabled, traffic is filtered based upon dynamic entries learned via DHCP
snooping (see “DHCP Snooping” on page 352), or static 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.
An entry with same MAC address and a different VLAN ID cannot be added to
the binding table.
Filtering rules are implemented as follows:
If DHCP snooping is disabled (see page 355), 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, 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 is 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
allowed by DHCP snooping.
Parameters
These parameters are displayed:
Port – The port identifier.
Filter Type – Configures the switch to filter inbound traffic based source IP
address, or source IP address and corresponding MAC address. (Default: None)
Disabled – Disables IP source guard filtering on the port.
SIP – Enables traffic filtering based on IP addresses stored in the binding
table.
SIP-MAC – Enables traffic filtering based on IP addresses and
corresponding MAC addresses stored in the binding table.
Filter Table – Sets the source guard learning model to search for addresses in
the ACL binding table or the MAC address binding table. (Default: ACL binding
table)