Configuring a manual mode IPsec tunnel for IPv4 packets

As shown in Figure 83, establish an IPsec tunnel between Switch A and Switch B to protect data flows between the switches. Configure the tunnel as follows:

• Specify the encapsulation mode as tunnel, the security protocol as ESP, the encryption algorithm as AES-CBC-192, and the authentication algorithm as HMAC-SHA1.

• Manually set up IPsec SAs.

  Figure 83: Network diagram

1. Configure Switch A:

   # Configure an IP address for 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
   

   # Configure an ACL to identify data flows between Switch A and 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] 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] protocol esp
   

   # Specify the ESP encryption and authentication algorithms.

   [SwitchA-ipsec-transform-set-tran1] esp encryption-algorithm aes-cbc-192
   [SwitchA-ipsec-transform-set-tran1] esp authentication-algorithm sha1
   [SwitchA-ipsec-transform-set-tran1] quit
   

   # Create a manual IPsec policy entry. Specify the policy name as map1 and set the sequence number to 10.

   [SwitchA] ipsec policy map1 10 manual
   

   # Apply ACL 3101.

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

   # Apply the IPsec transform set tran1.

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

   # Specify the remote IP address of the IPsec tunnel as 2.2.3.1.

   [SwitchA-ipsec-policy-manual-map1-10] remote-address 2.2.3.1
   

   # Configure inbound and outbound SPIs for ESP.

   [SwitchA-ipsec-policy-manual-map1-10] sa spi outbound esp 12345
   [SwitchA-ipsec-policy-manual-map1-10] sa spi inbound esp 54321
   

   # Configure the inbound and outbound SA keys for ESP.

   [SwitchA-ipsec-policy-manual-map1-10] sa string-key outbound esp simple abcdefg
   [SwitchA-ipsec-policy-manual-map1-10] sa string-key inbound esp simple gfedcba
   [SwitchA-ipsec-policy-manual-map1-10] quit
   

   # Apply the IPsec policy map1 to interface VLAN-interface 1.

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

2. Configure Switch B:

   # Configure an IP address for 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
   

   # Configure an ACL to identify data flows between Switch B and 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] 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] protocol esp
   

   # Specify the ESP encryption and authentication algorithms.

   [SwitchB-ipsec-transform-set-tran1] esp encryption-algorithm aes-cbc-192
   [SwitchB-ipsec-transform-set-tran1] esp authentication-algorithm sha1
   [SwitchB-ipsec-transform-set-tran1] quit
   

   # Create a manual IPsec policy entry. Specify the policy name as use1 and set the sequence number to 10.

   [SwitchB] ipsec policy use1 10 manual
   

   # Apply ACL 3101.

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

   # Apply IPsec transform set tran1.

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

   # Specify the remote IP address of the IPsec tunnel as 2.2.2.1.

   [SwitchB-ipsec-policy-manual-use1-10] remote-address 2.2.2.1
   

   # Configure the inbound and outbound SPIs for ESP.

   [SwitchB-ipsec-policy-manual-use1-10] sa spi outbound esp 54321
   [SwitchB-ipsec-policy-manual-use1-10] sa spi inbound esp 12345
   

   # Configure the inbound and outbound SA keys for ESP.

   [SwitchB-ipsec-policy-manual-use1-10] sa string-key outbound esp simple gfedcba
   [SwitchB-ipsec-policy-manual-use1-10] sa string-key inbound esp simple abcdefg
   [SwitchB-ipsec-policy-manual-use1-10] quit
   

   # Apply the IPsec policy use1 to interface VLAN-interface 1.

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

After the configuration is completed, an IPsec tunnel between Switch A and Switch B is established, and the traffic between the switches is IPsec protected. This example uses Switch A to verify the configuration.

# Use the display ipsec sa command to display IPsec SAs on Switch A.

[SwitchA] display ipsec sa
-------------------------------
Interface: Vlan-interface 1
-------------------------------

  -----------------------------
  IPsec policy: map1
  Sequence number: 10
  Mode: manual
  -----------------------------
    Tunnel id: 549
    Encapsulation mode: tunnel
    Path MTU: 1443
    Tunnel:
        local  address: 2.2.2.1
        remote address: 2.2.3.1
    Flow:
        as defined in ACL 3101
    [Inbound ESP SA]
      SPI: 54321 (0x0000d431)
      Transform set: ESP-ENCRYPT-AES-CBC-192 ESP-AUTH-SHA1
      No duration limit for this SA
    [Outbound ESP SA]
      SPI: 12345 (0x00003039)
      Transform set: ESP-ENCRYPT-AES-CBC-192 ESP-AUTH-SHA1
      No duration limit for this SA