ZyXEL Communications OLT2406 - IP Source Guard Setup; What You Need to Know

Chapter 27 IP Source Guard
OLT2406 User’s Guide
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• Use the ARP Inspection Port Configure screen (Section 27.9.1 on page 239) to specify whether ports
are trusted or untrusted ports for ARP inspection.
• Use the ARP Inspection VLAN Configure screen (Section 27.9.2 on page 240) to enable ARP inspection
on each VLAN and to specify when the OLT generates log messages for receiving ARP packets from
each VLAN.
27.1.2 What You Need to Know
The OLT builds the binding table by snooping DHCP packets (dynamic bindings) and from information
provided manually by administrators (static bindings).
IP source guard consists of the following features:
• Static bindings. Use this to create static bindings in the binding table.
• DHCP snooping. Use this to filter unauthorized DHCP packets on the network and to build the binding
table dynamically.
• ARP inspection. Use this to filter unauthorized ARP packets on the network.
If you want to use dynamic bindings to filter unauthorized ARP packets (typical implementation), you
have to enable DHCP snooping before you enable ARP inspection.
27.2 IP Source Guard Setup
Use this screen to look at the current bindings for DHCP snooping and ARP inspection. Bindings are used
by DHCP snooping and ARP inspection to distinguish between authorized and unauthorized packets in
the network. The OLT learns the bindings by snooping DHCP packets (dynamic bindings) and from
information provided manually by administrators (static bindings). To open this screen, click Advanced
Application > IP Source Guard > IP Source Guard Setup.
Figure 133 Advanced Application > IP Source Guard
The following table describes the labels in this screen.
Table 81 Advanced Application > IP Source Guard
LABEL DESCRIPTION
Index This field displays a sequential number for each binding.
MAC Address This field displays the source MAC address in the binding.
IP Address This field displays the IP address assigned to the MAC address in the binding.
Lease This field displays how many days, hours, minutes, and seconds the binding is valid; for
example, 2d3h4m5s means the binding is still valid for 2 days, 3 hours, 4 minutes, and 5
seconds. This field displays infinity if the binding is always valid (for example, a static binding).
Type This field displays how the OLT learned the binding.
static: This binding was learned from information provided manually by an administrator.
dhcp-snooping: This binding was learned by snooping DHCP packets.