Reference Guide

IPv4 Routing | 481
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
z
Disable the hop-count increment for the DHCP relay agent.
Syntax
ip helper-address hop-count disable
To reenable the hop-count increment, use the no ip helper-address hop-count disable command.
Defaults
Enabled; the hops field in the DHCP message header is incremented by default
Command Modes
CONFIGURATION
Command History
Usage Information
This command disables the incrementing of the hops field when boot requests are relayed to a DHCP
server through FTOS. If the incoming boot request already has a non-zero hops field, the message will
be relayed with the same value for hops. However, the message will be discarded if the hops field
exceeds 16, to comply with the relay agent behavior specified in RFC 1542.
Related
Commands
ip-address
Enter an IP address in dotted decimal format (A.B.C.D).
ipv6-address
Enter the IPv6 address in the x:x:x:x::x format
Note: The notation specifies successive hexadecimal fields of zeros.
default-vrf
(Optional) Enter default-vrf for the DHCP server VRF is using.
Version 9.0.2.0 Introduced on the S6000.
Version 8.3.11.1 Introduced on Z9000
Version 8.3.11.1 Added support for IPv6
S6000
Version 9.0.2.0 Introduced on the S6000.
Version 8.3.11.1 Introduced on Z9000
ip helper-address Specify the destination broadcast or host address for DHCP server requests.
show running-config Display the current configuration and changes from default values.