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FUJITSU PSWITCH
User’s Guide
108
December/2018
IPSG uses two enforcement mechanisms: the L2FDB to enforce the source MAC
address and ingress VLAN and an ingress classifier to enforce the source IP address
or {source IP, source MAC} pair.
3.1.5.11.2.
IPv6 Source Guard
IPv6 source guard (IPv6SG) is a security feature that filters IPv6 packets based on
source ID. The source ID is either a source IPv6 address or {source IPv6 address and
source MAC address pair}. The network administrator configures whether
enforcement includes the source MAC address.
The DHCPv6 snooping binding database and static IPv6SG entries configured by
administrator are identified as authorized source IDs.
Initially, all IPv6 traffic on the IPv6SG enabled port is blocked except for DHCPv6
packets. After a client receives an IP address from the DHCPv6 server, or after a
static IPv6 source binding is configured by the administrator, all traffic with that
IPv6 source address is permitted from that client. Traffic from other hosts is denied.
For each source ID in the binding database and for all manual IPv6SG entries,
IPv6SG notifies the driver to install an ingress classifier rule permitting matching
packets. If source MAC checking is configured, the classifier verifies that the {source
IPv6 address, source MAC address} pair matches a DHCP binding. The hardware
drops unauthorized packets. If the number of stations on a port exceeds the
available number of classifier rules, then the hardware installs rules for the number
of source IDs that fit. Traffic from other sources is dropped.
IPv6SG is enabled on physical and LAG ports. IPv6SG is disabled by default. Zero,
multicast and loopback IPv6 addresses are not allowed to configure as IPv6 static
source guard entry.
3.1.5.12.
Dynamic ARP Inspection
Dynamic ARP Inspection (DAI) is a security feature that rejects invalid and
malicious ARP packets. The feature prevents a class of man-in-the-middle attacks,
where an unfriendly station intercepts traffic for other stations by poisoning the
ARP caches of its neighbors. The miscreant sends ARP requests or responses
mapping another station IP address to its own MAC address.
DAI drops ARP packets whose sender MAC address and sender IP address do not
match an entry in the DHCP Snooping binding database.