Configuring DHCPv6 service requirements


ipv6 nd ra managed–config–flag

no ipv6 nd ra managed–config–flag

ipv6 nd ra other–config–flag

no ipv6 nd ra other–config–flag

managed–config–flag : Controls the M-bit setting in RAs the router transmits on the current VLAN. Enabling the M-bit directs clients to acquire their IPv6 addressing and ND host configuration information for the current VLAN interface from a DHCPv6 server.

  • When the M-bit is enabled, receiving hosts ignore the other–config–flag (O-bit) setting described below.

  • When the M-bit is disabled (the default), receiving hosts expect to receive their IPv6 addressing and ND configuration settings from the RA unless the O-bit is enabled.

other–config–flag : Ignored unless the M-bit (above) is disabled in RAs. Controls the O-bit in RAs the router transmits on the current VLAN.

Enabling the O-bit while the M-bit is disabled directs hosts on the VLAN to acquire their ND configuration settings from a DHCPv6 server and their global unicast prefixes from the RA.

The no form of either command turns off (disables) the setting for that command in RAs.


In the default configuration, both the M-bit and the O-bit are disabled, and a host receiving the RA must acquire its prefix and ND configuration from the RA itself and not from a DHCPv6 server.

Default for both settings: Disabled