CHAPTER
1-1
Cisco ASA Series CLI Configuration Guide
1
Configuring IP Addresses for VPNs
This chapter describes IP address assignment methods.
IP addresses make internetwork connections possible. They are like telephone numbers: both the sender
and receiver must have an assigned number to connect. But with VPNs, there are actually two sets of
addresses: the first set connects client and server on the public network. Once that connection is made,
the second set connects client and server through the VPN tunnel.
In ASA address management, we are dealing with the second set of IP addresses: those private IP
addresses that connect a client with a resource on the private network, through the tunnel, and let the
client function as if it were directly connected to the private network. Furthermore, we are dealing only
with the private IP addresses that get assigned to clients. The IP addresses assigned to other resources
on your private network are part of your network administration responsibilities, not part of VPN
management. Therefore, when we discuss IP addresses here, we mean those IP addresses available in
your private network addressing scheme that let the client function as a tunnel endpoint.
This chapter includes the following sections:
• Configuring an IP Address Assignment Policy, page 1-1
• Configuring Local IP Address Pools, page 1-3
• Configuring AAA Addressing, page 1-5
• Configuring DHCP Addressing, page 1-6
Configuring an IP Address Assignment Policy
The ASA can use one or more of the following methods for assigning IP addresses to remote access
clients. If you configure more than one address assignment method, the ASA searches each of the
options until it finds an IP address. By default, all methods are enabled.
• aaa — Retrieves addresses from an external authentication, authorization, and accounting server on
a per-user basis. If you are using an authentication server that has IP addresses configured, we
recommend using this method. This method is available for IPv4 and IPv6 assignment policies.
• dhcp — Obtains IP addresses from a DHCP server. If you want to use DHCP, you must configure a
DHCP server. You must also define the range of IP addresses that the DHCP server can use. This
method is available for IPv4 assignment policies.
• local — Internally configured address pools are the easiest method of address pool assignment to
configure. If you choose local, you must also use the ip-local-pool command to define the range of
IP addresses to use. This method is available for IPv4 and IPv6 assignment policies.
To Next Page
Loading...
Need help?
General
