Cisco 500 Series, Configuration Manual

Page: 753 / 1140

36-5
Cisco Security Appliance Command Line Configuration Guide
OL-12172-03
Chapter 36 Configuring LAN-to-LAN IPSec VPNs
Defining a Tunnel Group
Step 1
Enter the access-list extended command. The following example configures an ACL named l2l_list that
lets traffic from IP addresses in the 192.168.0.0 network travel to the 150.150.0.0 network. The syntax
is
access-list listname extended permit ip source-ipaddress source-netmask destination-ipaddress
destination-netmask.
hostname(config)# access-list l2l_list extended permit ip 192.168.0.0 255.255.0.0
150.150.0.0 255.255.0.0
hostname(config)#
Step 2 Configure an ACL for the security appliance on the other side of the connection that mirrors the ACL
above. In the following example the prompt for the peer is hostname2.
hostname2(config)# access-list l2l_list extended permit ip 150.150.0.0 255.255.0.0
192.168.0.0 255.255.0.0
hostname(config)#
Defining a Tunnel Group
A tunnel group is a set of records that contain tunnel connection policies. You configure a tunnel group
to identify AAA servers, specify connection parameters, and define a default group policy. The security
appliance stores tunnel groups internally.
There are two default tunnel groups in the security appliance system: DefaultRAGroup, which is the
default IPSec remote-access tunnel group, and DefaultL2Lgroup, which is the default IPSec
LAN-to-LAN tunnel group. You can modify them but not delete them. You can also create one or more
new tunnel groups to suit your environment. The security appliance uses these groups to configure
default tunnel parameters for remote access and LAN-to-LAN tunnel groups when there is no specific
tunnel group identified during tunnel negotiation.
To establish a basic LAN-to-LAN connection, you must set two attributes for a tunnel group:
• Set the connection type to IPSec LAN-to-LAN.
•
Configure an authentication method, in the following example, preshared key.
Step 1
To set the connection type to IPSec LAN-to-LAN, enter the tunnel-group command. The syntax is
tunnel-group name type type, where name is the name you assign to the tunnel group, and type is the
type of tunnel. The tunnel types as you enter them in the CLI are:
• ipsec-ra (IPSec remote access)
•
ipsec-l2l (IPSec LAN to LAN)
In the following example the name of the tunnel group is the IP address of the LAN-to-LAN peer,
10.10.4.108.
hostname(config)# tunnel-group 10.10.4.108 type ipsec-l2l
hostname(config)#
Step 2
To set the authentication method to preshared key, enter the ipsec-attributes mode and then enter the
pre-shared-key command to create the preshared key. You need to use the same preshared key on both
security appliances for this LAN-to-LAN connection.
The key is an alphanumeric string of 1-128 characters. In the following example the preshared key is
44kkaol59636jnfx.
hostname(config)# tunnel-group 10.10.4.108 ipsec-attributes