ZyXEL Communications ONU-2024 Series, User Manual

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Chapter 21 IP Source Guard
ONU User’s Guide
161
Trusted vs. Untrusted Ports
Every port is either a trusted port or an untrusted port for ARP inspection. The ONU does not
discard ARP packets on trusted ports for any reason. The ONU discards ARP packets on
untrusted ports if the sender’s information in the ARP packet does not match any of the current
bindings.
Syslog
The ONU can send syslog messages to the specified syslog server ( Chapter 29 on page 219 )
when it forwards or discards ARP packets. The ONU can consolidate log messages and send
log messages in batches to make this mechanism more efficient.
Configuring ARP Inspection
Follow these steps to configure ARP inspection on the ONU.
1 Configure static bindings so the ONU can distinguish between authorized and
unauthorized ARP packets.
2 Enable ARP inspection on the ONU.
3
Enable ARP inspection on each VLAN.
4 Configure trusted and untrusted ports, and specify the maximum number of ARP packets
that each port can receive per second.
21.2 IP Source Guard
Use this screen to look at the current bindings for ARP inspection. Bindings are used by ARP
inspection to distinguish between authorized and unauthorized packets in the network. The
ONU learns the bindings from information provided manually by administrators (static
bindings). To open this screen, click
Advanced Application > IP Source Guard .
Figure 80 IP Source Guard
The following table describes the labels in this screen.
Table 55 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 ONU learned the binding.
static : This binding was learned from information provided manually by an
administrator.