Cisco ASA 5505 - Manual (Page 1382)

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Cisco ASA 5500 Series Configuration Guide using the CLI
Chapter 64 Configuring IPsec and ISAKMP
Configuring IPsec
access-list access-list-name {deny | permit} ip source source-netmask destination
destination-netmask
For example:
hostname(config)# access-list 101 permit ip 10.0.0.0 255.255.255.0 10.1.1.0 255.255.255.0
In this example, the permit keyword causes all traffic that matches the specified conditions to be
protected by crypto.
Step 2 To configure an IKEv1 transform set that defines how to protect the traffic, enter the following
command:
crypto ipsec ikev1 transform-set transform-set-name encryption [authentication]
For example:
hostname(config)# crypto ipsec ikev1 transform-set myset1 esp-des esp-sha-hmac
hostname(config)# crypto ipsec ikev1 transform-set myset2 esp-3des esp-sha-hmac
hostname(config)# crypto ipsec ikev1 transform-set aes_set esp-md5-hmac esp-aes-256
In this example, myset1 and myset2 and aes_set are the names of the transform sets.
To configure an IKEv2 proposal that also defines how to protect the traffic, enter the crypto ipsec ikev2
ipsec-proposal command to create the proposal and enter the ipsec proposal configuration mode where
you can specify multiple encryption and integrity types for the proposal:
crypto ipsec ikev2 ipsec-proposal [proposal tag]
For example:
hostname(config)# crypto ipsec ikev2 ipsec-proposal secure
In this example, secure is the name of the proposal. Enter a protocol and encryption types:
hostname(config-ipsec-proposal)# protocol esp encryption 3des aes des
Step 3 To create a crypto map, perform the following steps:
a. Assign an access list to a crypto map:
crypto map map-name seq-num match address access-list-name
In the following example, mymap is the name of the crypto map set. The map set sequence number
10, which is used to rank multiple entries within one crypto map set. The lower the sequence
number, the higher the priority.
crypto map mymap 10 match address 101
In this example, the access list named 101 is assigned to crypto map mymap.
b. Specify the peer to which the IPsec-protected traffic can be forwarded:
crypto map map-name seq-num set peer ip-address
For example:
crypto map mymap 10 set peer 192.168.1.100
The ASA sets up an SA with the peer assigned the IP address 192.168.1.100. Specify multiple peers
by repeating this command.
c. Specify which IKEv1 transform sets or IKEv2 proposals are allowed for this crypto map. List
multiple transform sets or proposals in order of priority (highest priority first). You can specify up
to 11 transform sets or proposals in a crypto map using either of these two commands: