IPv6 First-Hop Security Features
1. Router Advertisement (RA) Guard: is a feature that analyzes RAs and can filter out unwanted RAs from unauthorized devices.
2. DHCP guard: The DHCPv6 Guard feature blocks reply and advertisement messages that come from unauthorized DHCP servers and relay agents
3. Binding Table: The binding table is a database that lists IPv6 neighbors that are connected to a device.
4. IPv6 neighbor discovery inspection/snooping: It is a feature that learns and populates the binding table for stateless auto-configuration addresses.
5. Source guard:IPv6 Source Guard is a Layer 2 snooping interface feature for validating the source of IPv6 traffic. If the traffic arriving on an interface is from an unknown source, IPv6 Source Guard can block it.
6. It is likely that the DHCP information available with the client workstation had become obsolete. Issuing "ipconfig" command with /release and /renew commands will enable the client workstation to obtain latest changes to the DHCP server.
1. Router#show ip dhcp conflict: This command shows information about IP conflicts that are detected during the DHCP negotiation. IP conflicts occur when hosts have statically assigned IP addresses that are within the DHCP configured range, but are not excluded.
2. Router>show ip dhcp binding [IP-address] The following examples show the DHCP binding address parameters, including an IP address, an associated MAC address, a lease expiration date, and the type of address assignment that have occurred.
Example:Router>show ip dhcp binding 172.16.1.11
IP address Hardware address Lease expiration Type 172.16.2.22 00a0.9802.32fc Feb 21 2016 12:00 AM Automatic
3. To display Cisco IOS DHCP Server database agent information, use the show ip dhcp database privileged EXEC command.
show ip dhcp database [url]
Related command: ip dhcp database: Configures a Cisco IOS DHCP Server to save automatic bindings on a remote host called a database agent.
