Dhcp Server Access; Switch, Dhcp Clients, And Dhcp Server Are All On The Same Vlan - Juniper JUNOS OS 10.4 - FOR EX REV 1 Manual

DHCP Server Access

Copyright © 2010, Juniper Networks, Inc.
NOTE: DHCPDISCOVER and DHCPOFFER packets are not snooped. The
DHCP database is updated only after the DHCPREQEST packet has been
sent.
For general information about the messages that the DHCP client and DHCP server
exchange during the assignment of an IP address for the client, see the
Basics Configuration Guide.
Switch access to the DHCP server can be configured in three ways:
Switch, DHCP Clients, and DHCP Server Are All on the Same VLAN on page 3055
Switch Acts as DHCP Server on page 3056
Switch Acts as Relay Agent on page 3057

Switch, DHCP Clients, and DHCP Server Are All on the Same VLAN

When the switch, DHCP clients, and DHCP server are all members of the same VLAN,
the DHCP server can be connected to the switch in one of two ways:
The server is directly connected to the same switch as the one connected to the DHCP
clients (the hosts, or network devices, that are requesting IP addresses from the server).
You must configure the port that connects the server to the switch as a trusted port.
See Figure 69 on page 3056.
The server is directly connected to a switch that is itself directly connected through a
trunk port to the switch that the DHCP clients are connected to. The trunk port is
configured by default as a trusted port. The switch that the DHCP server is connected
to is not configured for DHCP snooping. See Figure 70 on page 3056—in the figure,
ge-0/0/11 is a trusted trunk port.
Chapter 99: Port Security Overview
Junos OS System
3055