Web Management Guide-R04

Table Of Contents
Chapter 12
| Security Measures
IPv6 Source Guard
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Configuring Ports for
IPv6 Source Guard
Use the Security > IPv6 Source Guard > Port Configuration page to filter inbound
traffic based on the source IPv6 address or address prefix stored in the binding
table.
IPv6 Source Guard is used to filter traffic on an insecure port which receives
messages from outside the network or fire wall, and therefore may be subject to
traffic attacks caused by a host trying to use the IPv6 address of a neighbor.
Command Usage
Setting source guard mode to SIP (Source IP) or SDP (Source Prefix) enables this
function on the selected port. Enable IPv6 source guard to check the VLAN ID,
IPv6 global unicast source IP address or address prefix, and port number
against all entries in the binding table.
After IPv6 source guard is enabled on an interface, the switch initially blocks all
IPv6 traffic received on that interface, except for ND packets allowed by ND
snooping and DHCPv6 packets allowed by DHCPv6 snooping. A port access
control list (ACL) is applied to the interface. Traffic is then filtered based upon
dynamic entries learned via ND snooping or DHCPv6 snooping, or static
addresses configured in the source guard binding table. The port allows only
IPv6 traffic with a matching entry in the binding table and denies all other IPv6
traffic.
Table entries include a MAC address, IPv6 global unicast address, source-
delegated IPv6 prefix, entry type (Static-IPv6-SG-Binding, Dynamic-ND-
Binding, Dynamic-DHCPv6-Binding), VLAN identifier, and port identifier.
Static addresses entered in the source guard binding table (using the Static
Binding page) are automatically configured with an infinite lease time.
Dynamic entries learned via DHCPv6 snooping are configured by the DHCPv6
server itself.
If IPv6 source guard is enabled, an inbound packet’s source IPv6 address or
address prefix 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 ND snooping and DHCPv6 snooping are disabled, IPv6 source guard will
check the VLAN ID, source IPv6 address or address prefix, and port number.
If a matching entry is found in the binding table and the entry type is static
IPv6 source guard binding, the packet will be forwarded.
If ND snooping or DHCP snooping is enabled, IPv6 source guard will check
the VLAN ID, source IP address or address prefix, and port number. If a
matching entry is found in the binding table and the entry type is static
IPv6 source guard binding, dynamic ND snooping binding, or dynamic
DHCPv6 snooping binding, the packet will be forwarded.
If IPv6 source guard is enabled on an interface for which IPv6 source
bindings (dynamically learned via ND snooping or DHCPv6 snooping, or
manually configured) are not yet configured, the switch will drop all IPv6