Enhancements
Release M.10.43 Enhancements
• Remove the
■You can configure dynamic IP lockdown only from the CLI; this feature cannot be configured from the Web management or menu interface.
■If you enable dynamic IP lockdown on a port, you cannot add the port to a trunk.
■Dynamic IP lockdown must be removed from a trunk before the trunk is removed.
Adding an
A switch maintains a DHCP binding database, which is used for dynamic IP lockdown as well as for DHCP and ARP packet validation. The DHCP snooping feature maintains the lease database by learning the
Dynamic IP lockdown supports a total of 4K static and dynamic bindings with up to 64 bindings per port. When DHCP snooping is enabled globally on a VLAN, dynamic bindings are learned when a client on the VLAN obtains an IP address from a DHCP server. Static bindings are created manually with the CLI or from a downloaded configuration file.
When dynamic IP lockdown is enabled globally or on ports the bindings associated with the ports are written to hardware. This occurs during these events:
■Switch initialization
■Hot swap
■A dynamic IP
■DHCP snooping or dynamic IP lockdown characteristics are changed such that dynamic IP lockdown is enabled on the ports
Potential Issues with Bindings■When dynamic IP lockdown enabled, and a port or switch has the maximum number of bindings configured, the client DHCP request will be dropped and the client will not receive an IP address through DHCP.
■When dynamic IP lockdown is enabled and a port is configured with the maximum number of bindings, adding a static binding to the port will fail.
■When dynamic IP lockdown is enabled globally, the bindings for each port are written to hardware. If global dynamic IP lockdown is enabled and disabled several times, it is possible to run out of buffer space for additional bindings. The software will delay adding the bindings to hardware until resources are available.
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