Command Reference Guide

IPv4 Routing | 665
c e s
Specify the address of a DHCP server so that DHCP broadcast messages can be forwarded
when the DHCP server is not on the same subnet as the client.
Syntax
ip helper-address ip-address | default-vrf
To remove a DHCP server address, enter no ip helper-address.
Parameters
Defaults
Not configured.
Command Modes
INTERFACE
Command
History
Usage
Information
You can add multiple DHCP servers by entering the ip helper-address command multiple
times. If multiple servers are defined, an incoming request is sent simultaneously to all
configured servers and the reply is forwarded to the DHCP client.
FTOS uses standard DHCP ports, that is UDP ports 67 (server) and 68 (client) for DHCP
relay services. It listens on port 67 and if it receives a broadcast, the software converts it to
unicast, and forwards to it to the DHCP-server with source port=68 and destination port=67.
The server replies with source port=67, destination port=67 and FTOS forwards to the client
with source port=67, destination port=68.
ip helper-address hop-count disable
ip-address
Enter an IP address in dotted decimal format (A.B.C.D).
default-vrf (Optional) E-Series Only: Enter default-vrf for the DHCP server VRF
is using.
Version 8.3.7.0 Introduced on S4810
Version 8.1.1.0 Introduced on E-Series ExaScale
Version 7.9.1.0 Introduced VRF on the E-Series
Version 7.6.1.0 Added support for S-Series
Version 7.5.1.0 Added support for C-Series
pre-Version 6.2.1.1 Introduced on E-Series