Users Guide

Command Mode INTERFACE CONFIGURATION
Usage
Information
The VRF values for subnet selection are sent to the DHCP server in the option 151 field only if ip
dhcp-relay vss-enable is enabled at the Global level. The value of the VRF name must match a
VRF configured on the DHCP server for a DHCP pool. It is not the name of a VRF configured on the local
switch, as a result, no validation is performed.
● To send the VRF information to the DHCP server, set the vss-info type as type-0 or type-1 and
configure the corresponding VRF name string or VRF Octet value, respectively, on the interface.
● If a no value or type-255 is passed as the vss value, the IP address is allocated from the default
address pool of the server corresponding to the link selection subnet.
● The type 0 and type 1 values configured on the client interfaces must contain the server-side VRF
DHCP pool information. It is used by the server to allocate IP address to the clients from the
requested VRF pool. The configured type 0 or type 1 value must be the VRF or VPN ID associated
with the DHCP pool in the server.
You can configure the vss-info on all types of the DHCP client interfaces (Ethernet interface, port-
channel, VLAN, and virtual-network).
NOTE: With VSS enabled, change in the vss-info configuration value at the interface after the
client IP assignment takes effect in the subsequent renew process. If the client receives a NACK, the
client starts the discovery process with the new values.
This command is restricted to
netadmin and sysadmin role users.
Example
OS10(conf-if-eth1/1/1)# ip dhcp-relay
server-override Enable dhcp-relay server overrride sub-option
source-interface Source interface for dhcp relay
vss-info Configure VSS information
OS10-8986(conf-if-eth1/1/1)# ip dhcp-relay vss-info
type Configure VSS type
OS10-8986(conf-if-eth1/1/1)# ip dhcp-relay vss-info type
0 Type-0
1 Type-1
255 Type-255 for global/default address space
OS10(config)# interface ethernet 1/1/1
OS10(conf-if-eth1/1/1)# ip dhcp-relay vss-info type 0 value vrf_red
OS10(conf-if-eth1/1/1)# ip dhcp-relay vss-info type 1 value F10:1234
OS10(conf-if-eth1/1/1)# ip dhcp-relay vss-info type 255
Supported
Releases
10.5.2 or later
ip dhcp-relay link-selection
Enables link-selection (suboption-5) globally on the relay agent.
Syntax
ip dhcp-relay link-selection
Parameters None.
Defaults Disabled on the relay agent.
Command Mode CONFIGURATION
Usage
Information
After enabling the link-selection option, the DHCPv4 link-selection support is enabled Globally.
Anycast gateway IP address or client interface IP address is filled in the link-selection option to
communicate the client subnet to the DHCP server.
318 System management