Cisco ASA 5505 - Manual (Page 1521)

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Cisco ASA 5500 Series Configuration Guide using the CLI
Chapter 68 Configuring IP Addresses for VPNs
Configuring an IP Address Assignment Method
hostname(config)# vpn-addr-assign aaa
hostname(config)#
Step 2 To establish the tunnel group called firstgroup as a remote access or LAN-to-LAN tunnel group, enter
the tunnel-group command with the type keyword. The following example configures a remote access
tunnel group.
hostname(config)# tunnel-group firstgroup type ipsec-ra
hostname(config)#
Step 3 To enter general-attributes configuration mode, which lets you define a AAA server group for the tunnel
group called firstgroup, enter the tunnel-group command with the general-attributes argument.
hostname(config)# tunnel-group firstgroup general-attributes
hostname(config-general)#
Step 4 To specify the AAA server group to use for authentication, enter the authentication-server-group
command.
hostname(config-general)# authentication-server-group RAD2
hostname(config-general)#
This command has more arguments that this example includes. For more information, see the command
reference.
Configuring DHCP Addressing
To use DHCP to assign addresses for VPN clients, you must first configure a DHCP server and the range
of IP addresses that the DHCP server can use. Then you define the DHCP server on a tunnel group basis.
Optionally, you can also define a DHCP network scope in the group policy associated with the tunnel
group or username. This is either an IP network number or IP Address that identifies to the DHCP server
which pool of IP addresses to use.
The following examples define the DHCP server at IP address 172.33.44.19 for the tunnel group named
firstgroup. They also define a DHCP network scope of 192.86.0.0 for the group policy called
remotegroup. (The group policy called remotegroup is associated with the tunnel group called
firstgroup). If you do not define a network scope, the DHCP server assigns IP addresses in the order of
the address pools configured. It goes through the pools until it identifies an unassigned address.
The following configuration includes more steps than are necessary, in that previously you might have
named and defined the tunnel group type as remote access, and named and identified the group policy
as internal or external. These steps appear in the following examples as a reminder that you have no
access to subsequent tunnel-group and group-policy commands until you set these values.
A summary of the configuration that these examples create follows:
hostname(config)# vpn-addr-assign dhcp
hostname(config)# tunnel-group firstgroup type ipsec-ra
hostname(config)# tunnel-group firstgroup general-attributes
hostname(config-general)# dhcp-server 172.33.44.19
hostname(config-general)# exit
hostname(config)# group-policy remotegroup internal
hostname(config)# group-policy remotegroup attributes
hostname(config-group-policy)# dhcp-network-scope 192.86.0.0
To define a DHCP server for IP addressing, perform the following steps.