Licensing Requirements for DHCP
This table shows the licensing requirements for DHCP.
License Requirement
Product
DHCP requires no license. Any feature not included in a license package is bundled with the
nx-os image and is provided at no extra charge to you. For an explanation of the Cisco NX-OS
licensing scheme, see the
Cisco NX-OS Licensing Guide
.
Cisco NX-OS
Prerequisites for DHCP
DHCP has the following prerequisite:
• You should be familiar with DHCP before you configure DHCP snooping or the DHCP relay agent.
Guidelines and Limitations for DHCP
DHCP has the following configuration guidelines and limitations:
• For secure POAP, make sure that DHCP snooping is enabled and firewall rules are set to block unintended
or malicious DHCP servers.
• Cisco Nexus 9000 Series switches do not support the relaying of bootp packets. However, the switches
do support bootp packets that are Layer 2 switched.
• DHCP subnet broadcast is not supported.
• You must enable the insertion of Option 82 information for DHCP packets to support the highest DHCP
snooping scale.
• Before you globally enable DHCP snooping on the device, make sure that the devices acting as the DHCP
server and the DHCP relay agent are configured and enabled.
• DHCP snooping should not be followed by DHCP relay in the network (DHCP snooping does not work
when the DHCP relay is configured on the same Nexus device).
• DHCP snooping is not supported on VXLAN VLANs.
• DHCP snooping supports multiple IP addresses with the same MAC address and VLAN in static binding
entries.
• VXLAN supports DHCP relay when the DHCP server is reachable through a default VRF.
• If a VLAN ACL (VACL) is configured on a VLAN that you are configuring with DHCP snooping, make
sure that the VACL permits DHCP traffic between DHCP servers and DHCP hosts. When both DHCP
snooping and DHCP relay are enabled on a VLAN and the SVI of that VLAN, DHCP relay takes
precedence.
Cisco Nexus 9000 Series NX-OS Security Configuration Guide, Release 9.x
335
Configuring DHCP
Licensing Requirements for DHCP