Administrator Guide

Displaying the Contents of the DHCPv6 Binding Table
To display the contents of the DHCP IPv6 binding table, use the following command.
• Display the contents of the binding table.
EXEC Privilege mode
show ipv6 dhcp snooping biniding
Example of the show ipv6 dhcp snooping binding Command
View the DHCP snooping statistics with the show ipv6 dhcp snooping command.
Dell#show ipv6 dhcp snooping binding
Codes : S - Static D – Dynamic
IPv6 Address MAC Address Expires(Sec) Type VLAN Interface
=========================================================================
11:11::22 11:22:11:22:11:22 120331 S Vl 100 Gi 1/1
33::22 11:22:11:22:11:23 120331 S Vl 200 Gi 1/1
333:22::22 11:22:11:22:11:24 120331 D Vl 300 Gi 1/2
Debugging the IPv6 DHCP
To debug the IPv6 DHCP, use the following command.
• Display debug information for IPV6 DHCP.
EXEC Privilege mode
debug ipv6 dhcp
IPv6 DHCP Snooping MAC-Address Verication
Congure to enable verify source mac-address in the DHCP packet against the mac address stored in the snooping binding table.
• Enable IPV6 DHCP snooping .
CONFIGURATION mode
ipv6 dhcp snooping verify mac-address
Drop DHCP Packets on Snooped VLANs Only
Binding table entries are deleted when a lease expires or the relay agent encounters a DHCPRELEASE.
Line cards maintain a list of snooped VLANs. When the binding table lls, DHCP packets are dropped only on snooped VLANs, while such
packets are forwarded across non-snooped VLANs. Because DHCP packets are dropped, no new IP address assignments are made.
However, DHCP release and decline packets are allowed so that the DHCP snooping table can decrease in size. After the table usage falls
below the maximum limit of 4000 entries, new IP address assignments are allowed.
To view the number of entries in the table, use the show ip dhcp snooping binding command. This output displays the snooping
binding table created using the ACK packets from the trusted port.
Dell#show ip dhcp snooping binding
Codes : S - Static D - Dynamic
IP Address MAC Address Expires(Sec) Type VLAN Interface
260
Dynamic Host Conguration Protocol (DHCP)