ZyXEL Communications GS1510-16 -, Руководство пользователя

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GS1510 Series User’s Guide
103
C
H A P T E R
18
IP Source Guard
18.1 Overview
Use the IP source guard screens to filter unauthorized DHCP and ARP packets in
your network. IP source guard uses a binding table to distinguish between the
authorized and unauthorized DHCP and ARP packets in your network.
18.2 What You Can Do
• Use the DHCP Snooping screens ( Section 18.4 on page 107 ) to filter
unauthorized DHCP packets on the network and to build the binding table
dynamically.
• Use the ARP Inspection screens ( Section 18.6 on page 110 ) to filter
unauthorized ARP packets on the network.
• Use the Binding Table screens ( Section 18.7 on page 112 ) to manually enter
static bindings and to convert dynamic bindings to static.
18.3 What You Need To Know
A binding in the IP source guard binding table contains these key attributes:
• MAC address
• VLAN ID
• IP address
• Port number
When the Switch receives an ARP packet, it looks up the appropriate MAC address,
VLAN ID, IP address, and port number in the binding table. If there is a binding,
the Switch forwards the packet. If there is not a binding, the Switch discards the
packet.
The Switch builds the binding table by snooping DHCP packets (dynamic bindings)
and from information provided manually by administrators (static bindings).