IKE-based IPsec tunnel for IPv4 packets configuration example

As shown in Figure 85, configure an IPsec tunnel between Switch A and Switch B to protect data flows between Switch A and Switch B. Configure the tunnel to use the security protocol ESP, the encryption algorithm AES-CBC-128, and the authentication algorithm HMAC-SHA1-96.

# Assign an IP address to VLAN-interface 1.

<SwitchA> system-view
[SwitchA] interface vlan-interface 1
[SwitchA-Vlan-interface1] ip address 2.2.2.1 255.255.255.0
[SwitchA-Vlan-interface1] quit

# Define an ACL to identify data flows from Switch A to Switch B.

[SwitchA] acl number 3101
[SwitchA-acl-adv-3101] rule 0 permit ip source 2.2.2.1 0 destination 2.2.3.1 0
[SwitchA-acl-adv-3101] rule 5 permit ip source 2.2.3.1 0 destination 2.2.2.1 0
[SwitchA-acl-adv-3101] quit

# Create an IPsec transform set named tran1.

[SwitchA] ipsec transform-set tran1

# Specify the encapsulation mode as tunnel.

[SwitchA-ipsec-transform-set-tran1] encapsulation-mode tunnel

# Specify the security protocol as ESP.

[SwitchA-ipsec-transform-set-tran1] transform esp

# Specify the algorithms for the transform set.

[SwitchA-ipsec-transform-set-tran1] esp encryption-algorithm aes-cbc-128
[SwitchA-ipsec-transform-set-tran1] esp authentication-algorithm sha1
[SwitchA-ipsec-transform-set-tran1] quit

# Configure the IKE peer.

[SwitchA] ike peer peer
[SwitchA-ike-peer-peer] pre-shared-key Ab12<><>
[SwitchA-ike-peer-peer] remote-address 2.2.3.1
[SwitchA-ike-peer-peer] quit

# Create an IKE-based IPsec policy for IPsec SA negotiation.

[SwitchA] ipsec policy map1 10 isakmp

# Apply the IPsec transform set.

[SwitchA-ipsec-policy-isakmp-map1-10] transform-set tran1

# Apply the ACL.

[SwitchA-ipsec-policy-isakmp-map1-10] security acl 3101

# Apply the IKE peer.

[SwitchA-ipsec-policy-isakmp-map1-10] ike-peer peer
[SwitchA-ipsec-policy-isakmp-map1-10] quit

# Apply the IPsec policy group to VLAN-interface 1.

[SwitchA] interface vlan-interface 1
[SwitchA-Vlan-interface1] ipsec policy map1

# Assign an IP address to VLAN-interface 1.

<SwitchB> system-view
[SwitchB] interface vlan-interface 1
[SwitchB-Vlan-interface1] ip address 2.2.3.1 255.255.255.0
[SwitchB-Vlan-interface1] quit

# Define an ACL to identify data flows from Switch B to Switch A.

[SwitchB] acl number 3101
[SwitchB-acl-adv-3101] rule 0 permit ip source 2.2.3.1 0 destination 2.2.2.1 0
[SwitchB-acl-adv-3101] rule 5 permit ip source 2.2.2.1 0 destination 2.2.3.1 0
[SwitchB-acl-adv-3101] quit

# Create an IPsec transform set named tran1.

[SwitchB] ipsec transform-set tran1

# Specify the encapsulation mode as tunnel.

[SwitchB-ipsec-transform-set-tran1] encapsulation-mode tunnel

# Specify the security protocol as ESP.

[SwitchB-ipsec-transform-set-tran1] transform esp

# Specify the algorithms for the transform set.

[SwitchB-ipsec-transform-set-tran1] esp encryption-algorithm aes-cbc-128
[SwitchB-ipsec-transform-set-tran1] esp authentication-algorithm sha1
[SwitchB-ipsec-transform-set-tran1] quit

# Configure the IKE peer.

[SwitchB] ike peer peer
[SwitchB-ike-peer-peer] pre-shared-key Ab12<><>
[SwitchB-ike-peer-peer] remote-address 2.2.2.1
[SwitchB-ike-peer-peer] quit

# Create an IKE-based IPsec policy for IPsec SA negotiation.

[SwitchB] ipsec policy use1 10 isakmp

# Apply the ACL.

[SwitchB-ipsec-policy-isakmp-use1-10] security acl 3101

# Apply the IPsec transform set.

[SwitchB-ipsec-policy-isakmp-use1-10] transform-set tran1

# Apply the IKE peer.

[SwitchB-ipsec-policy-isakmp-use1-10] ike-peer peer
[SwitchB-ipsec-policy-isakmp-use1-10] quit

# Apply the IPsec policy group to VLAN-interface 1.

[SwitchB] interface vlan-interface 1
[SwitchB-Vlan-interface1] ipsec policy use1

After the previous configuration, send traffic from Switch B to Switch A. Switch A starts IKE negotiation with Switch B when receiving the first packet. If IKE negotiation is successful and SAs are set up, the traffic between the two switches will be IPsec protected.