LAN Configuration
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ProSafe Gigabit Quad WAN SSL VPN Firewall SRX5308

DHCP Relay

DHCP relay options allow you to make the VPN firewall a DHCP relay agent for a VLAN. The
DHCP relay agent makes it possible for DHCP broadcast messages to be sent over routers
that do not support forwarding of these types of messages. The DHCP relay agent is
therefore the routing protocol that enables DHCP clients to obtain IP addresses from a DHCP
server on a remote subnet. If you do not configure a DHCP relay agent for a VLAN, its clients
can obtain IP addresses only from a DHCP server that is on the same subnet. To enable
clients to obtain IP addresses from a DHCP server on a remote subnet, you need to
configure the DHCP relay agent on the subnet that contains the remote clients, so that the
DHCP relay agent can relay DHCP broadcast messages to your DHCP server.

DNS Proxy

When the DNS proxy option is enabled for a VLAN, the VPN firewall acts as a proxy for all
DNS requests and communicates with the ISP’s DNS servers (as configured on the WAN
IPv4 ISP Settings screens). All DHCP clients receive the primary and secondary DNS IP
addresses along with the IP address where the DNS proxy is located (that is, the VPN
firewall’s LAN IP address). When the DNS proxy option is disabled for a VLAN, all DHCP
clients receive the DNS IP addresses of the ISP but without the DNS proxy IP address.

LDAP Server

A Lightweight Directory Access Protocol (LDAP) server allows a user to query and modify
directory services that run over TCP/IP. For example, clients can query email addresses,
contact information, and other service information using an LDAP server. For each VLAN,
you can specify an LDAP server and a search base that defines the location in the directory
(that is, the directory tree) from which the LDAP search begins.
Configure a VLAN Profile
For each VLAN on the VPN firewall, you can configure its profile, port membership, LAN
TCP/IP settings, DHCP options, DNS server, and inter-VLAN routing capability.
To add a VLAN profile:
1. Select Network Configuration > LAN Settings. In the upper right of the screen, the
IPv4 radio button is selected by default. The LAN submenu tabs display, with the LAN
Setup screen in view, displaying the IPv4 settings. (The following figure contains some
VLAN profiles as an example.)
Note: For information about how to manage VLANs, see Port-Based
VLANs on page 80. The following information describes how to
configure a VLAN profile.