Cisco Nexus 9000 Series - Default Settings for DHCP

• If an ingress router ACL is configured on a Layer 3 interface that you are configuring with a DHCP
server address, make sure that the router ACL permits DHCP traffic between DHCP servers and DHCP
hosts.
• If you use DHCP relay where DHCP clients and servers are in different VRFs, use only one DHCP server
within a VRF.
• Access-control list (ACL) statistics are not supported if the DHCP snooping feature is enabled.
• Make sure that the DHCP configuration is synchronized across the switches in a vPC link. Otherwise, a
run-time error can occur, resulting in dropped packets.
• DHCP smart relay is limited to the first 100 IP addresses of the interface on which it is enabled.
• You must configure a helper address on the interface in order to use DHCP smart relay.
• In a vPC environment with DHCP smart relay enabled, the subnet of the primary and secondary addresses
of an interface should be the same on both Cisco NX-OS devices.
• When you configure DHCPv6 server addresses on an interface, a destination interface cannot be used
with global IPv6 addresses.
• The following guidelines and limitations apply to the DHCP client feature:
• You can configure multiple SVIs, but each interface VLAN should be in a different subnet. The
DHCP client feature cannot configure different IP addresses with the same subnet on different
interface VLANs on the same device.
• DHCP client and DHCP relay are not supported on the same switch.
• DHCP client is not supported for Layer 3 subinterfaces.
• DHCP client is supported on the Cisco Nexus 9300 Series switches and the Cisco Nexus 9500 Series
switches.
For DHCP configuration limits, see the Cisco Nexus 9000 Series NX-OS Verified Scalability Guide.
Note
Default Settings for DHCP
This table lists the default settings for DHCP parameters.
Table 32: Default DHCP Parameters
DefaultParameters
DisabledDHCP feature
DisabledDHCP snooping
DisabledDHCP snooping on VLANs
EnabledDHCP snooping MAC address verification
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Configuring DHCP
Default Settings for DHCP