Dynamic IP source guard entries
Dynamic IP source guard entries are generated dynamically according to client entries on the DHCP snooping device or the DHCP relay agent device. They are applicable in cases where many hosts reside on a LAN and obtain IP addresses through DHCP. Once DHCP allocates an IP address to a client, IP source guard automatically adds the client entry to allow the client to access the network. Users with IP addresses not obtained through DHCP cannot access the network. Dynamic IPv6 source guard entries can also be obtained from client entries on the ND snooping device.
Dynamic IPv4 source guard entries are generated dynamically based on DHCP snooping or DHCP relay entries to filter incoming IPv4 packets on a port.
Dynamic IPv6 source guard entries are generated dynamically based on DHCPv6 snooping or ND snooping entries to filter incoming IPv6 packets on a port.
For information about DHCP snooping, DHCP relay, DHCPv6 snooping, and ND snooping, see Layer 3—IP Services Configuration Guide.