Command Line Reference Guide

Command History
Version 9.0(1.3) Introduced on the S5000.
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
Disable the hop-count increment for the DHCP relay agent.
S5000
Syntax
ip helper-address hop-count disable
To re-enable 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
Version 9.0(1.3) Introduced on the S5000.
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 is relayed with the same value for hops. However, the message is discarded if the
hops field exceeds 16, to comply with the relay agent behavior specified in RFC 1542.
Related
Commands
ip helper-address – specifies the destination broadcast or host address for DHCP server
requests.
show running-config – displays the current configuration and changes from the default values.
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