Site-to-Site IPSEC VPN setup guide using StrongSwan on Ubuntu and Cisco IOS Print

  • Cisco Firewall, IPSEC VPN, Strongswan VPN, OpenSwan VPN, CISCO IOS
  • 1

Introduction

 

This document provides a configuration example for a Site-to-Site VPN between customer’s Cisco IOS® and CloudAcropolis strongSwan VPN gateway. Both Internet Key Exchange version 1 (IKEv1) and Internet Key Exchange version 2 (IKEv2) configurations are presented.

Prerequisites

Requirements

It’s recommended that you have knowledge of these topics:

  • Basic knowledge about Linux configurations
  • Knowledge about VPN configurations on Cisco IOS
  • Knowledge about these protocols:
    • IKEv1
    • IKEv2
    • Internet Protocol Security (IPSec)

Components Used

The information in this document is based on these software versions:

 

  • Cisco IOS Release 15.3T
  • strongSwan 5.3.5
  • Linux kernel 3.2.12

Configure

Network Diagram

The topology is the same for both examples, which is a Site-to-Site (L2L) tunnel between Cisco IOS and strongSwan

Cisco_strongSwan

IKEv1 Between Cisco IOS and strongSwan

 

Cisco IOS Configuration

crypto isakmp policy 10
 encr aes
 authentication pre-share
 group 5
crypto isakmp key pRid@$tr6S4u address 172.16.10.2    

crypto ipsec transform-set TS esp-aes esp-sha-hmac 
 mode tunnel

crypto map cmap 10 ipsec-isakmp 
 set peer 172.16.10.2
 set transform-set TS 
 match address cryptoacl

interface Ethernet0/1
 ip address 192.168.1.1 255.255.255.0

interface Ethernet0/0
 ip address 172.16.10.1 255.255.255.0
 crypto map cmap

ip access-list extended cryptoacl
 permit ip 192.168.1.0 0.0.0.255 192.168.2.0 0.0.0.255

 

strongSwan Configuration

The left side is related to strongSwan and the right side is remote (Cisco IOS in this example).

/etc/ipsec.conf

config setup
        # strictcrlpolicy=yes
        # uniqueids = no

conn %default
        ikelifetime=1440m
        keylife=60m
        rekeymargin=3m
        keyingtries=1
        keyexchange=ikev1
        authby=secret

conn ciscoios
        left=172.16.10.2                  #strongswan outside address
        leftsubnet=192.168.2.0/24         #network behind strongswan
        leftid=172.16.10.2                #IKEID sent by strongswan
        leftfirewall=yes
        right=172.16.10.1                 #IOS outside address
        rightsubnet=192.168.1.0/24        #network behind IOS
        rightid=172.16.10.1               #IKEID sent by IOS
        auto=add
        ike=aes128-md5-modp1536           #P1: modp1536 = DH group 5
        esp=aes128-sha1                   #P2

By default, Cisco IOS uses the address as the IKE ID - that is why addresses have been used as 'rightid" and "leftid". strongSwan, like Cisco IOS, supports Next-Generation Cryptography (Suite B) - so it is possible to use 4096 Diffie-Hellman (DH) keys along with AES256 and SHA512. For auto parameter, the "add" argument has been used. That brings up the tunnel after it gets interesting traffic. In order to start it immediately, the "start" argument could be used. The following file needs to be edited:

/etc/ipsec.secrets

172.16.10.2 172.16.10.1 : PSK “pRid@$tr6S4u”

IKEv2 Between Cisco IOS and strongSwan

 

Cisco IOS Configuration

crypto ikev2 proposal ikev2proposal 
 encryption aes-cbc-128
 integrity sha1
 group 5

crypto ikev2 policy ikev2policy 
 match fvrf any
 proposal ikev2proposal

crypto ikev2 keyring keys
 peer strongswan
  address 172.16.10.2
  pre-shared-key local pRid@$tr6S4u
  pre-shared-key remote st!2ro0-WRlS
 
crypto ikev2 profile ikev2profile
 match identity remote address 172.16.10.2 255.255.255.255 
 authentication remote pre-share
 authentication local pre-share
 keyring local keys

crypto ipsec transform-set TS esp-aes esp-sha-hmac 
 mode tunnel

crypto map cmap 10 ipsec-isakmp 
 set peer 172.16.10.2
 set transform-set TS 
 set ikev2-profile ikev2profile
 match address cryptoacl

interface Ethernet0/1
 ip address 192.168.1.1 255.255.255.0

interface Ethernet0/0
 ip address 172.16.10.1 255.255.255.0
 crypto map cmap

ip access-list extended cryptoacl
 permit ip 192.168.1.0 0.0.0.255 192.168.2.0 0.0.0.255

strongSwan Configuration

There are only two changes in comparison to IKEv1: keyexchange and possibly keys. The following file needs to be edited: /etc/ipsec.conf

config setup
        # strictcrlpolicy=yes
        # uniqueids = no

conn %default
        ikelifetime=1440m
        keylife=60m
        rekeymargin=3m
        keyingtries=1
        keyexchange=ikev1
        authby=secret

conn ciscoios
        left=172.16.10.2
        leftsubnet=192.168.2.0/24
        leftid=172.16.10.2
        leftfirewall=yes
        right=172.16.10.1
        rightsubnet=192.168.1.0/24
        rightid=172.16.10.1
        auto=add
        ike=aes128-sha1-modp1536
        esp=aes128-sha1
        keyexchange=ikev2
/etc/ipsec.secrets
172.16.10.2 : PSK "pRid@$tr6S4u"
172.16.10.1 : PSK "st!2ro0-WRlS"

In IKEv2, keys for each site can be different.

 

Verify

See the Troubleshoot section for the verification procedures.

Troubleshoot

This section provides information you can use to troubleshoot your configuration.

IKEv1 Between Cisco IOS and strongSwan

 

Cisco IOS

ping 192.168.2.1 source e0/1 repeat 1

Tunnel Establishment Triggered by Cisco IOS

*May 24 18:02:48.464: IPSEC(sa_request): ,
  (key eng. msg.) OUTBOUND local= 172.16.10.1:500, remote= 172.16.10.2:500,
    local_proxy= 192.168.1.0/255.255.255.0/256/0,
    remote_proxy= 192.168.2.0/255.255.255.0/256/0,
    protocol= ESP, transform= esp-aes esp-sha-hmac  (Tunnel), 
    lifedur= 3600s and 4608000kb, 
    spi= 0x0(0), conn_id= 0, keysize= 128, flags= 0x0
*May 24 18:02:48.465: ISAKMP:(0): SA request profile is (NULL)
*May 24 18:02:48.465: ISAKMP: Created a peer struct for 172.16.10.2, peer port 500
*May 24 18:02:48.465: ISAKMP: New peer created peer = 0xF334E7E0 peer_handle =
 0x80000006
*May 24 18:02:48.465: ISAKMP: Locking peer struct 0xF334E7E0, refcount 1 for
 isakmp_initiator
*May 24 18:02:48.465: ISAKMP: local port 500, remote port 500
*May 24 18:02:48.465: ISAKMP: set new node 0 to QM_IDLE      
*May 24 18:02:48.465: ISAKMP: Find a dup sa in the avl tree during calling
 isadb_insert sa = F49C9890
*May 24 18:02:48.465: ISAKMP:(0):Can not start Aggressive mode, trying Main mode.
*May 24 18:02:48.465: ISAKMP:(0):found peer pre-shared key matching 172.16.10.2
*May 24 18:02:48.465: ISAKMP:(0): constructed NAT-T vendor-rfc3947 ID
*May 24 18:02:48.465: ISAKMP:(0): constructed NAT-T vendor-07 ID
*May 24 18:02:48.465: ISAKMP:(0): constructed NAT-T vendor-03 ID
*May 24 18:02:48.465: ISAKMP:(0): constructed NAT-T vendor-02 ID
*May 24 18:02:48.465: ISAKMP:(0):Input = IKE_MESG_FROM_IPSEC, IKE_SA_REQ_MM
*May 24 18:02:48.465: ISAKMP:(0):Old State = IKE_READY  New State = IKE_I_MM1 

*May 24 18:02:48.465: ISAKMP:(0): beginning Main Mode exchange
*May 24 18:02:48.465: ISAKMP:(0): sending packet to 172.16.10.2 my_port 500
 peer_port 500 (I) MM_NO_STATE
*May 24 18:02:48.465: ISAKMP:(0):Sending an IKE IPv4 Packet.
*May 24 18:02:48.466: ISAKMP (0): received packet from 172.16.10.2 dport 500
 sport 500 Global (I) MM_NO_STATE
*May 24 18:02:48.466: ISAKMP:(0):Input = IKE_MESG_FROM_PEER, IKE_MM_EXCH
*May 24 18:02:48.466: ISAKMP:(0):Old State = IKE_I_MM1  New State = IKE_I_MM2 

*May 24 18:02:48.466: ISAKMP:(0): processing SA payload. message ID = 0
*May 24 18:02:48.466: ISAKMP:(0): processing vendor id payload
*May 24 18:02:48.466: ISAKMP:(0): vendor ID seems Unity/DPD but major 215 mismatch
*May 24 18:02:48.466: ISAKMP:(0): vendor ID is XAUTH
*May 24 18:02:48.466: ISAKMP:(0): processing vendor id payload
*May 24 18:02:48.466: ISAKMP:(0): vendor ID is DPD
*May 24 18:02:48.466: ISAKMP:(0): processing vendor id payload
*May 24 18:02:48.466: ISAKMP:(0): vendor ID seems Unity/DPD but major 69 mismatch
*May 24 18:02:48.466: ISAKMP (0): vendor ID is NAT-T RFC 3947
*May 24 18:02:48.466: ISAKMP:(0):found peer pre-shared key matching 172.16.10.2
*May 24 18:02:48.466: ISAKMP:(0): local preshared key found
*May 24 18:02:48.466: ISAKMP : Scanning profiles for xauth ...
*May 24 18:02:48.466: ISAKMP:(0):Checking ISAKMP transform 1 against priority
 10 policy
*May 24 18:02:48.466: ISAKMP:      encryption AES-CBC
*May 24 18:02:48.466: ISAKMP:      keylength of 128
*May 24 18:02:48.466: ISAKMP:      hash SHA
*May 24 18:02:48.466: ISAKMP:      default group 5
*May 24 18:02:48.466: ISAKMP:      auth pre-share
*May 24 18:02:48.466: ISAKMP:      life type in seconds
*May 24 18:02:48.466: ISAKMP:      life duration (VPI) of  0x0 0x1 0x51 0x80 
*May 24 18:02:48.466: ISAKMP:(0):atts are acceptable. Next payload is 0
*May 24 18:02:48.466: ISAKMP:(0):Acceptable atts:actual life: 0
*May 24 18:02:48.466: ISAKMP:(0):Acceptable atts:life: 0
*May 24 18:02:48.466: ISAKMP:(0):Fill atts in sa vpi_length:4
*May 24 18:02:48.466: ISAKMP:(0):Fill atts in sa life_in_seconds:86400
*May 24 18:02:48.466: ISAKMP:(0):Returning Actual lifetime: 86400
*May 24 18:02:48.466: ISAKMP:(0)::Started lifetime timer: 86400.
          
*May 24 18:02:48.466: ISAKMP:(0): processing vendor id payload
*May 24 18:02:48.466: ISAKMP:(0): vendor ID seems Unity/DPD but major 215 mismatch
*May 24 18:02:48.466: ISAKMP:(0): vendor ID is XAUTH
*May 24 18:02:48.466: ISAKMP:(0): processing vendor id payload
*May 24 18:02:48.466: ISAKMP:(0): vendor ID is DPD
*May 24 18:02:48.466: ISAKMP:(0): processing vendor id payload
*May 24 18:02:48.466: ISAKMP:(0): vendor ID seems Unity/DPD but major 69 mismatch
*May 24 18:02:48.466: ISAKMP (0): vendor ID is NAT-T RFC 3947
*May 24 18:02:48.466: ISAKMP:(0):Input = IKE_MESG_INTERNAL, IKE_PROCESS_MAIN_MODE
*May 24 18:02:48.466: ISAKMP:(0):Old State = IKE_I_MM2  New State = IKE_I_MM2 

*May 24 18:02:48.466: ISAKMP:(0): sending packet to 172.16.10.2 my_port 500
 peer_port 500 (I) MM_SA_SETUP
*May 24 18:02:48.466: ISAKMP:(0):Sending an IKE IPv4 Packet.
*May 24 18:02:48.466: ISAKMP:(0):Input = IKE_MESG_INTERNAL, IKE_PROCESS_COMPLETE
*May 24 18:02:48.466: ISAKMP:(0):Old State = IKE_I_MM2  New State = IKE_I_MM3 

*May 24 18:02:48.474: ISAKMP (0): received packet from 172.16.10.2 dport 500 sport
 500 Global (I) MM_SA_SETUP
*May 24 18:02:48.474: ISAKMP:(0):Input = IKE_MESG_FROM_PEER, IKE_MM_EXCH
*May 24 18:02:48.474: ISAKMP:(0):Old State = IKE_I_MM3  New State = IKE_I_MM4 

*May 24 18:02:48.474: ISAKMP:(0): processing KE payload. message ID = 0
*May 24 18:02:48.482: ISAKMP:(0): processing NONCE payload. message ID = 0
*May 24 18:02:48.482: ISAKMP:(0):found peer pre-shared key matching 172.16.10.2
*May 24 18:02:48.482: ISAKMP:received payload type 20
*May 24 18:02:48.482: ISAKMP (1003): His hash no match - this node outside NAT
*May 24 18:02:48.482: ISAKMP:received payload type 20
*May 24 18:02:48.482: ISAKMP (1003): No NAT Found for self or peer
*May 24 18:02:48.482: ISAKMP:(1003):Input = IKE_MESG_INTERNAL, IKE_PROCESS_MAIN_MODE
*May 24 18:02:48.482: ISAKMP:(1003):Old State = IKE_I_MM4  New State = IKE_I_MM4 

*May 24 18:02:48.482: ISAKMP:(1003):Send initial contact
*May 24 18:02:48.482: ISAKMP:(1003):SA is doing pre-shared key authentication using 
id type ID_IPV4_ADDR
*May 24 18:02:48.482: ISAKMP (1003): ID payload 
        next-payload : 8
        type         : 1 
        address      : 172.16.10.1 
        protocol     : 17 
        port         : 500 
        length       : 12
*May 24 18:02:48.482: ISAKMP:(1003):Total payload length: 12
*May 24 18:02:48.482: ISAKMP:(1003): sending packet to 172.16.10.2 my_port 500
 peer_port 500 (I) MM_KEY_EXCH
*May 24 18:02:48.482: ISAKMP:(1003):Sending an IKE IPv4 Packet.
*May 24 18:02:48.482: ISAKMP:(1003):Input = IKE_MESG_INTERNAL, IKE_PROCESS_COMPLETE
*May 24 18:02:48.482: ISAKMP:(1003):Old State = IKE_I_MM4  New State = IKE_I_MM5 

*May 24 18:02:48.483: ISAKMP (1003): received packet from 172.16.10.2 dport 500
 sport 500 Global (I) MM_KEY_EXCH
*May 24 18:02:48.483: ISAKMP:(1003): processing ID payload. message ID = 0
*May 24 18:02:48.483: ISAKMP (1003): ID payload 
        next-payload : 8
        type         : 1 
        address      : 172.16.10.2 
        protocol     : 0 
        port         : 0 
        length       : 12
*May 24 18:02:48.483: ISAKMP:(0):: peer matches *none* of the profiles
*May 24 18:02:48.483: ISAKMP:(1003): processing HASH payload. message ID = 0
*May 24 18:02:48.483: ISAKMP:(1003):SA authentication status:
        authenticated
*May 24 18:02:48.483: ISAKMP:(1003):SA has been authenticated with 172.16.10.2
*May 24 18:02:48.483: ISAKMP: Trying to insert a peer 172.16.10.1/172.16.10.2/500/,
  and inserted successfully F334E7E0.
*May 24 18:02:48.483: ISAKMP:(1003):Input = IKE_MESG_FROM_PEER, IKE_MM_EXCH
*May 24 18:02:48.483: ISAKMP:(1003):Old State = IKE_I_MM5  New State = IKE_I_MM6 

*May 24 18:02:48.483: ISAKMP:(1003):Input = IKE_MESG_INTERNAL, IKE_PROCESS_MAIN_MODE
*May 24 18:02:48.483: ISAKMP:(1003):Old State = IKE_I_MM6  New State = IKE_I_MM6 

*May 24 18:02:48.487: ISAKMP:(1003):Input = IKE_MESG_INTERNAL, IKE_PROCESS_COMPLETE
*May 24 18:02:48.487: ISAKMP:(1003):Old State = IKE_I_MM6  New State = IKE_P1_COMPLETE

*May 24 18:02:48.487: ISAKMP:(1003):beginning Quick Mode exchange, M-ID of 2605730229
*May 24 18:02:48.487: ISAKMP:(1003):QM Initiator gets spi
*May 24 18:02:48.487: ISAKMP:(1003): sending packet to 172.16.10.2 my_port 500
 peer_port 500 (I) QM_IDLE      
*May 24 18:02:48.487: ISAKMP:(1003):Sending an IKE IPv4 Packet.
*May 24 18:02:48.488: ISAKMP:(1003):Node 2605730229, Input = IKE_MESG_INTERNAL,
 IKE_INIT_QM
*May 24 18:02:48.488: ISAKMP:(1003):Old State = IKE_QM_READY  New State = IKE_QM_I_QM1
*May 24 18:02:48.488: ISAKMP:(1003):Input = IKE_MESG_INTERNAL, IKE_PHASE1_COMPLETE
*May 24 18:02:48.488: ISAKMP:(1003):Old State = IKE_P1_COMPLETE  New State =
 IKE_P1_COMPLETE

*May 24 18:02:48.488: ISAKMP (1003): received packet from 172.16.10.2 dport 500
 sport 500 Global (I) QM_IDLE      
*May 24 18:02:48.488: ISAKMP:(1003): processing HASH payload. message ID = 2605730229
*May 24 18:02:48.488: ISAKMP:(1003): processing SA payload. message ID = 2605730229
*May 24 18:02:48.488: ISAKMP:(1003):Checking IPSec proposal 1
*May 24 18:02:48.488: ISAKMP: transform 1, ESP_AES 
*May 24 18:02:48.488: ISAKMP:   attributes in transform:
*May 24 18:02:48.488: ISAKMP:      key length is 128
*May 24 18:02:48.488: ISAKMP:      authenticator is HMAC-SHA
*May 24 18:02:48.488: ISAKMP:      encaps is 1 (Tunnel)
*May 24 18:02:48.488: ISAKMP:      SA life type in seconds
*May 24 18:02:48.488: ISAKMP:      SA life duration (basic) of 3600
*May 24 18:02:48.488: ISAKMP:      SA life type in kilobytes
*May 24 18:02:48.488: ISAKMP:      SA life duration (VPI) of  0x0 0x46 0x50 0x0 
*May 24 18:02:48.488: ISAKMP:(1003):atts are acceptable.
*May 24 18:02:48.488: IPSEC(validate_proposal_request): proposal part #1
*May 24 18:02:48.488: IPSEC(validate_proposal_request): proposal part #1,
  (key eng. msg.) INBOUND local= 172.16.10.1:0, remote= 172.16.10.2:0,
    local_proxy= 192.168.1.0/255.255.255.0/256/0,
    remote_proxy= 192.168.2.0/255.255.255.0/256/0,
    protocol= ESP, transform= NONE  (Tunnel), 
    lifedur= 0s and 0kb, 
    spi= 0x0(0), conn_id= 0, keysize= 128, flags= 0x0
*May 24 18:02:48.488: Crypto mapdb : proxy_match
        src addr     : 192.168.1.0
        dst addr     : 192.168.2.0
        protocol     : 0
        src port     : 0
        dst port     : 0
*May 24 18:02:48.488: ISAKMP:(1003): processing NONCE payload. message ID = 2605730229
*May 24 18:02:48.488: ISAKMP:(1003): processing ID payload. message ID = 2605730229
*May 24 18:02:48.488: ISAKMP:(1003): processing ID payload. message ID = 2605730229
*May 24 18:02:48.488: ISAKMP:(1003):Node 2605730229, Input = IKE_MESG_FROM_PEER,
 IKE_QM_EXCH
*May 24 18:02:48.488: ISAKMP:(1003):Old State = IKE_QM_I_QM1  New State =
 IKE_QM_IPSEC_INSTALL_AWAIT
*May 24 18:02:48.488: IPSEC(key_engine): got a queue event with 1 KMI message(s)
*May 24 18:02:48.488: Crypto mapdb : proxy_match
        src addr     : 192.168.1.0
        dst addr     : 192.168.2.0
        protocol     : 256
        src port     : 0
        dst port     : 0
*May 24 18:02:48.488: IPSEC(crypto_ipsec_create_ipsec_sas): Map found cmap
*May 24 18:02:48.489: IPSEC(crypto_ipsec_sa_find_ident_head): reconnecting with the
 same proxies and peer 172.16.10.2
*May 24 18:02:48.489: IPSEC(create_sa): sa created,
  (sa) sa_dest= 172.16.10.1, sa_proto= 50, 
    sa_spi= 0x4C0D0EF0(1275924208), 
    sa_trans= esp-aes esp-sha-hmac , sa_conn_id= 7
    sa_lifetime(k/sec)= (4608000/3600)
*May 24 18:02:48.489: IPSEC(create_sa): sa created,
  (sa) sa_dest= 172.16.10.2, sa_proto= 50, 
    sa_spi= 0xC72072C6(3340792518), 
    sa_trans= esp-aes esp-sha-hmac , sa_conn_id= 8
    sa_lifetime(k/sec)= (4608000/3600)

In both phases Internet Security Association and Key Management Protocol (ISAKMP) and IPSec are up.

Cisco IOS: Check IPSec Counters

R1#show crypto session detail 
Crypto session current status

Code: C - IKE Configuration mode, D - Dead Peer Detection     
K - Keepalives, N - NAT-traversal, T - cTCP encapsulation     
X - IKE Extended Authentication, F - IKE Fragmentation

Interface: Ethernet0/0
Uptime: 00:00:05
Session status: UP-ACTIVE     
Peer: 172.16.10.2 port 500 fvrf: (none) ivrf: (none)
      Phase1_id: 172.16.10.2
      Desc: (none)
  IKEv1 SA: local 172.16.10.1/500 remote 172.16.10.2/500 Active 
          Capabilities:(none) connid:1003 lifetime:23:59:54
  IPSEC FLOW: permit ip 192.168.1.0/255.255.255.0 192.168.2.0/255.255.255.0 
        Active SAs: 2, origin: crypto map
        Inbound:  #pkts dec'ed 0 drop 0 life (KB/Sec) 4164218/3594
        Outbound: #pkts enc'ed 0 drop 0 life (KB/Sec) 41
After 100 packets are sent:
R1#ping 192.168.2.1 source e0/1 repeat 100
Type escape sequence to abort.
Sending 100, 100-byte ICMP Echos to 192.168.2.1, timeout is 2 seconds:
Packet sent with a source address of 192.168.1.1 
!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
Success rate is 100 percent (100/100), round-trip min/avg/max = 4/4/5 ms
R1#

R1#show crypto session detail              
Crypto session current status

Code: C - IKE Configuration mode, D - Dead Peer Detection     
K - Keepalives, N - NAT-traversal, T - cTCP encapsulation     
X - IKE Extended Authentication, F - IKE Fragmentation

Interface: Ethernet0/0
Uptime: 00:00:09
Session status: UP-ACTIVE     
Peer: 172.16.10.2 port 500 fvrf: (none) ivrf: (none)
      Phase1_id: 172.16.10.2
      Desc: (none)
  IKEv1 SA: local 172.16.10.1/500 remote 172.16.10.2/500 Active 
          Capabilities:(none) connid:1003 lifetime:23:59:50
  IPSEC FLOW: permit ip 192.168.1.0/255.255.255.0 192.168.2.0/255.255.255.0 
        Active SAs: 2, origin: crypto map
        Inbound:  #pkts dec'ed 100 drop 0 life (KB/Sec) 4164202/3590
        Outbound: #pkts enc'ed 100 drop 0 life (KB/Sec) 4164202/3590

Cisco IOS: Verify IKEv1 and IPSec Parameters

R1#show crypto isakmp sa detail 
Codes: C - IKE configuration mode, D - Dead Peer Detection
       K - Keepalives, N - NAT-traversal
       T - cTCP encapsulation, X - IKE Extended Authentication
       psk - Preshared key, rsig - RSA signature
       renc - RSA encryption
IPv4 Crypto ISAKMP SA

C-id  Local           Remote          I-VRF  Status Encr Hash   Auth DH Lifetime Cap.

1003  172.16.10.1     172.16.10.2            ACTIVE aes  sha    psk  5  23:59:35     
       Engine-id:Conn-id =  SW:3


R1#show crypto ipsec sa 
interface: Ethernet0/0
    Crypto map tag: cmap, local addr 172.16.10.1

   protected vrf: (none)
   local  ident (addr/mask/prot/port): (192.168.1.0/255.255.255.0/0/0)
   remote ident (addr/mask/prot/port): (192.168.2.0/255.255.255.0/0/0)
   current_peer 172.16.10.2 port 500
     PERMIT, flags={origin_is_acl,}
    #pkts encaps: 100, #pkts encrypt: 100, #pkts digest: 100
    #pkts decaps: 100, #pkts decrypt: 100, #pkts verify: 100
    #pkts compressed: 0, #pkts decompressed: 0
    #pkts not compressed: 0, #pkts compr. failed: 0
    #pkts not decompressed: 0, #pkts decompress failed: 0
    #send errors 0, #recv errors 0

     local crypto endpt.: 172.16.10.1, remote crypto endpt.: 172.16.10.2
     plaintext mtu 1438, path mtu 1500, ip mtu 1500, ip mtu idb Ethernet0/0
     current outbound spi: 0xC72072C6(3340792518)
     PFS (Y/N): N, DH group: none

     inbound esp sas:
      spi: 0x4C0D0EF0(1275924208)
        transform: esp-aes esp-sha-hmac ,
        in use settings ={Tunnel, }
        conn id: 7, flow_id: SW:7, sibling_flags 80000040, crypto map: cmap
        sa timing: remaining key lifetime (k/sec): (4164202/3562)
        IV size: 16 bytes
        replay detection support: Y
        Status: ACTIVE(ACTIVE)

     inbound ah sas:

     inbound pcp sas:

     outbound esp sas:
      spi: 0xC72072C6(3340792518)
        transform: esp-aes esp-sha-hmac ,
        in use settings ={Tunnel, }
        conn id: 8, flow_id: SW:8, sibling_flags 80000040, crypto map: cmap
        sa timing: remaining key lifetime (k/sec): (4164202/3562)
        IV size: 16 bytes
        replay detection support: Y
        Status: ACTIVE(ACTIVE)

     outbound ah sas:
          
     outbound pcp sas:
Both phases are up. The IPSec Security Parameter Index (SPI) is negotiated. The counter has increased to 100 after 100 packets are sent.

strongSwan: Tunnel Establishment

pluton# /etc/init.d/ipsec start

May 24 20:02:48 localhost charon: 10[NET] received packet: from 172.16.10.1[500]
 to 172.16.10.2[500] (168 bytes)
May 24 20:02:48 localhost charon: 10[ENC] parsed ID_PROT request 0 [ SA V V V V ]
May 24 20:02:48 localhost charon: 10[IKE] received NAT-T (RFC 3947) vendor ID
May 24 20:02:48 localhost charon: 10[IKE] received draft-ietf-ipsec-nat-t-ike-07
 vendor ID
May 24 20:02:48 localhost charon: 10[IKE] received draft-ietf-ipsec-nat-t-ike-03
 vendor ID
May 24 20:02:48 localhost charon: 10[IKE] received draft-ietf-ipsec-nat-t-ike-02\n
 vendor ID
May 24 20:02:48 localhost charon: 10[IKE] 172.16.10.1 is initiating a Main Mode IKE_SA
May 24 20:02:48 localhost charon: 10[IKE] 172.16.10.1 is initiating a Main Mode IKE_SA
May 24 20:02:48 localhost charon: 10[ENC] generating ID_PROT response 0 [ SA V V V ]
May 24 20:02:48 localhost charon: 10[NET] sending packet: from 172.16.10.2[500] to
 172.16.10.1[500] (140 bytes)
May 24 20:02:48 localhost charon: 11[NET] received packet: from 172.16.10.1[500] to
 172.16.10.2[500] (348 bytes)
May 24 20:02:48 localhost charon: 11[ENC] parsed ID_PROT request 0
 [ KE No V V V NAT-D NAT-D ]
May 24 20:02:48 localhost charon: 11[ENC] generating ID_PROT response 0
 [ KE No NAT-D NAT-D ]
May 24 20:02:48 localhost charon: 11[NET] sending packet: from 172.16.10.2[500]
 to 172.16.10.1[500] (308 bytes)
May 24 20:02:48 localhost charon: 12[NET] received packet: from 172.16.10.1[500]
 to 172.16.10.2[500] (108 bytes)
May 24 20:02:48 localhost charon: 12[ENC] parsed ID_PROT request 0
 [ ID HASH N(INITIAL_CONTACT) ]
May 24 20:02:48 localhost charon: 12[CFG] looking for pre-shared key peer configs
 matching 172.16.10.2...172.16.10.1[172.16.10.1]
May 24 20:02:48 localhost charon: 12[CFG] selected peer config "ciscoios"
May 24 20:02:48 localhost charon: 12[IKE] IKE_SA ciscoios[2] established between
 172.16.10.2[172.16.10.2]...172.16.10.1[172.16.10.1]
May 24 20:02:48 localhost charon: 12[IKE] IKE_SA ciscoios[2] established between
 172.16.10.2[172.16.10.2]...172.16.10.1[172.16.10.1]
May 24 20:02:48 localhost charon: 12[IKE] scheduling reauthentication in 3289s
May 24 20:02:48 localhost charon: 12[IKE] maximum IKE_SA lifetime 3469s
May 24 20:02:48 localhost charon: 12[ENC] generating ID_PROT response 0 [ ID HASH ]
May 24 20:02:48 localhost charon: 12[NET] sending packet: from 172.16.10.2[500] to
 172.16.10.1[500] (76 bytes)
May 24 20:02:48 localhost charon: 14[NET] received packet: from 172.16.10.1[500] to
 172.16.10.2[500] (188 bytes)
May 24 20:02:48 localhost charon: 14[ENC] parsed QUICK_MODE request 2605730229
 [ HASH SA No ID ID ]
May 24 20:02:48 localhost charon: 14[IKE] received 3600s lifetime, configured 1200s
May 24 20:02:48 localhost charon: 14[IKE] received 4608000000 lifebytes, configured 0
May 24 20:02:48 localhost charon: 14[ENC] generating QUICK_MODE response 2605730229
 [ HASH SA No ID ID ]
May 24 20:02:48 localhost charon: 14[NET] sending packet: from 172.16.10.2[500] to
 172.16.10.1[500] (188 bytes)
May 24 20:02:48 localhost charon: 15[NET] received packet: from 172.16.10.1[500] to
 172.16.10.2[500] (60 bytes)
May 24 20:02:48 localhost charon: 15[ENC] parsed QUICK_MODE request 2605730229 [ HASH ]
May 24 20:02:48 localhost charon: 15[IKE] CHILD_SA ciscoios{2} established with SPIs
 c72072c6_i 4c0d0ef0_o and TS 192.168.2.0/24 === 192.168.1.0/24 
May 24 20:02:48 localhost charon: 15[IKE] CHILD_SA ciscoios{2} established with SPIs
 c72072c6_i 4c0d0ef0_o and TS 192.168.2.0/24 === 192.168.1.0/24 
May 24 20:02:48 localhost vpn: + 172.16.10.1 192.168.1.0/24 == 172.16.10.1 --
 172.16.10.2 == 192.168.2.0/24

Both phases are up. The correct SPIs that protect the traffic between 192.168.2.0/24 and 192.168.1.0/24 are negotiated.

strongSwan: Verify IPSec Connection Status

pluton ~ # ipsec statusall
Status of IKE charon daemon (strongSwan 5.0.4, Linux 3.2.12-gentoo, x86_64):
  uptime: 4 minutes, since May 24 20:02:15 2013
  malloc: sbrk 393216, mmap 0, used 274064, free 119152
  worker threads: 8 of 16 idle, 7/1/0/0 working, job queue: 0/0/0/0, scheduled: 4
  loaded plugins: charon mysql sqlite aes des sha1 sha2 md5 random nonce x509
 revocation constraints pubkey pkcs1 pkcs8 pgp dnskey pem openssl gcrypt fips-prf
 gmp xcbc cmac hmac attr kernel-netlink resolve socket-default stroke updown
 eap-identity eap-sim eap-aka eap-aka-3gpp2 eap-simaka-pseudonym eap-simaka-reauth
 eap-md5 eap-gtc eap-mschapv2 eap-radius xauth-generic
Listening IP addresses:
  10.0.0.100
  192.168.10.1
  172.16.10.2
  192.168.2.1
Connections:
    ciscoios:  172.16.10.2...172.16.10.1  IKEv1
    ciscoios:   local:  [172.16.10.2] uses pre-shared key authentication
    ciscoios:   remote: [172.16.10.1] uses pre-shared key authentication
    ciscoios:   child:  192.168.2.0/24 === 192.168.1.0/24 TUNNEL
Security Associations (1 up, 0 connecting):
    ciscoios[2]: ESTABLISHED 4 minutes ago, 172.16.10.2[172.16.10.2]...
172.16.10.1[172.16.10.1]
    ciscoios[2]: IKEv1 SPIs: 278f22e3c3e5f606_i dbb5a27f3e0eccd1_r*, 
pre-shared key reauthentication in 50 minutes
    ciscoios[2]: IKE proposal: AES_CBC_128/HMAC_SHA1_96/PRF_HMAC_SHA1/MODP_1536
    ciscoios{2}:  INSTALLED, TUNNEL, ESP SPIs: c72072c6_i 4c0d0ef0_o
    ciscoios{2}:  AES_CBC_128/HMAC_SHA1_96, 10000 bytes_i (100 pkts, 255s ago), 
10000 bytes_o (100 pkts, 255s ago), rekeying in 11 minutes
    ciscoios{2}:   192.168.2.0/24 === 192.168.1.0/24

The details about the negotiated ISAKMP and IPSec parameters are available.

strongSwan: Verify IPSec Policy

pluton ~ # ip -s xfrm policy
src 192.168.1.0/24 dst 192.168.2.0/24 uid 0
        dir fwd action allow index 258 priority 1859 share any flag  (0x00000000)
        lifetime config:
          limit: soft (INF)(bytes), hard (INF)(bytes)
          limit: soft (INF)(packets), hard (INF)(packets)
          expire add: soft 0(sec), hard 0(sec)
          expire use: soft 0(sec), hard 0(sec)
        lifetime current:
          0(bytes), 0(packets)
          add 2013-05-24 20:02:48 use -
        tmpl src 172.16.10.1 dst 172.16.10.2
                proto esp spi 0x00000000(0) reqid 2(0x00000002) mode tunnel
                level required share any 
                enc-mask ffffffff auth-mask ffffffff comp-mask ffffffff
src 192.168.1.0/24 dst 192.168.2.0/24 uid 0
        dir in action allow index 248 priority 1859 share any flag  (0x00000000)
        lifetime config:
          limit: soft (INF)(bytes), hard (INF)(bytes)
          limit: soft (INF)(packets), hard (INF)(packets)
          expire add: soft 0(sec), hard 0(sec)
          expire use: soft 0(sec), hard 0(sec)
        lifetime current:
          0(bytes), 0(packets)
          add 2013-05-24 20:02:48 use 2013-05-24 20:02:56
        tmpl src 172.16.10.1 dst 172.16.10.2
                proto esp spi 0x00000000(0) reqid 2(0x00000002) mode tunnel
                level required share any 
                enc-mask ffffffff auth-mask ffffffff comp-mask ffffffff
src 192.168.2.0/24 dst 192.168.1.0/24 uid 0
        dir out action allow index 241 priority 1859 share any flag  (0x00000000)
        lifetime config:
          limit: soft (INF)(bytes), hard (INF)(bytes)
          limit: soft (INF)(packets), hard (INF)(packets)
          expire add: soft 0(sec), hard 0(sec)
          expire use: soft 0(sec), hard 0(sec)
        lifetime current:
          0(bytes), 0(packets)
          add 2013-05-24 20:02:48 use 2013-05-24 20:02:56
        tmpl src 172.16.10.2 dst 172.16.10.1
                proto esp spi 0x00000000(0) reqid 2(0x00000002) mode tunnel
                level required share any 
                enc-mask ffffffff auth-mask ffffffff comp-mask ffffffff

The previous details include internal policy tables.

IKEv2 Between Cisco IOS and strongSwan Cisco IOS

R1#ping 192.168.2.1 source e0/1 repeat 1
Tunnel Establishment Triggered by Cisco IOS
*May 24 19:14:10.485: IPSEC(sa_request): ,
  (key eng. msg.) OUTBOUND local= 172.16.10.1:500, remote= 172.16.10.2:500,
    local_proxy= 192.168.1.0/255.255.255.0/256/0,
    remote_proxy= 192.168.2.0/255.255.255.0/256/0,
    protocol= ESP, transform= esp-aes esp-sha-hmac  (Tunnel), 
    lifedur= 3600s and 4608000kb, 
    spi= 0x0(0), conn_id= 0, keysize= 128, flags= 0x0
*May 24 19:14:10.486: IKEv2:% Getting preshared key from profile keyring keys
*May 24 19:14:10.486: IKEv2:% Matched peer block 'strongswan'
*May 24 19:14:10.486: IKEv2:Searching Policy with fvrf 0, local address 172.16.10.1
*May 24 19:14:10.486: IKEv2:Found Policy 'ikev2policy'
*May 24 19:14:10.486: IKEv2:(SA ID = 1):[IKEv2 -> Crypto Engine] Computing DH public
 key, DH Group 5
*May 24 19:14:10.486: IKEv2:(SA ID = 1):[Crypto Engine -> IKEv2] DH key Computation
 PASSED
*May 24 19:14:10.486: IKEv2:(SA ID = 1):Request queued for computation of DH key
*May 24 19:14:10.486: IKEv2:IKEv2 initiator - no config data to send in IKE_SA_INIT exch
*May 24 19:14:10.486: IKEv2:(SA ID = 1):Generating IKE_SA_INIT message
*May 24 19:14:10.486: IKEv2:(SA ID = 1):IKE Proposal: 1, SPI size: 0
 (initial negotiation), 
Num. transforms: 4
   AES-CBC   SHA1   SHA96   DH_GROUP_1536_MODP/Group 5 

*May 24 19:14:10.486: IKEv2:(SA ID = 1):Sending Packet [To 172.16.10.2:500/From
 172.16.10.1:500/VRF i0:f0] 
Initiator SPI : 9FFC38791FFEF212 - Responder SPI : 0000000000000000 Message id: 0
IKEv2 IKE_SA_INIT Exchange REQUEST 
Payload contents: 
 SA KE N VID VID NOTIFY(NAT_DETECTION_SOURCE_IP) NOTIFY(NAT_DETECTION_DESTINATION_IP) 

*May 24 19:14:10.486: IKEv2:(SA ID = 1):Insert SA 

*May 24 19:14:10.495: IKEv2:(SA ID = 1):Received Packet [From 172.16.10.2:500/To
 172.16.10.1:500/VRF i0:f0] 
Initiator SPI : 9FFC38791FFEF212 - Responder SPI : 6CDC17F5B0B10C1A Message id: 0
IKEv2 IKE_SA_INIT Exchange RESPONSE 
Payload contents: 
 SA KE N NOTIFY(NAT_DETECTION_SOURCE_IP) NOTIFY(NAT_DETECTION_DESTINATION_IP)
 NOTIFY(Unknown - 16404) 
          
*May 24 19:14:10.495: IKEv2:(SA ID = 1):Processing IKE_SA_INIT message
*May 24 19:14:10.495: IKEv2:(SA ID = 1):Verify SA init message
*May 24 19:14:10.495: IKEv2:(SA ID = 1):Processing IKE_SA_INIT message
*May 24 19:14:10.495: IKEv2:(SA ID = 1):Checking NAT discovery
*May 24 19:14:10.495: IKEv2:(SA ID = 1):NAT not found
*May 24 19:14:10.495: IKEv2:(SA ID = 1):[IKEv2 -> Crypto Engine] Computing DH
 secret key, DH Group 5
*May 24 19:14:10.504: IKEv2:(SA ID = 1):[Crypto Engine -> IKEv2] DH key Computation
 PASSED
*May 24 19:14:10.504: IKEv2:(SA ID = 1):Request queued for computation of DH secret
*May 24 19:14:10.504: IKEv2:(SA ID = 1):[IKEv2 -> Crypto Engine] Calculate SKEYSEED
 and create rekeyed IKEv2 SA
*May 24 19:14:10.504: IKEv2:(SA ID = 1):[Crypto Engine -> IKEv2] SKEYSEED
 calculation and creation of
 rekeyed IKEv2 SA PASSED
*May 24 19:14:10.504: IKEv2:(SA ID = 1):Completed SA init exchange
*May 24 19:14:10.504: IKEv2:(SA ID = 1):Check for EAP exchange
*May 24 19:14:10.504: IKEv2:(SA ID = 1):Generate my authentication data
*May 24 19:14:10.504: IKEv2:(SA ID = 1):Use preshared key for id 172.16.10.1,
 key len 5
*May 24 19:14:10.504: IKEv2:[IKEv2 -> Crypto Engine] Generate IKEv2 authentication
 data
*May 24 19:14:10.504: IKEv2:[Crypto Engine -> IKEv2] IKEv2 authentication data
 generation PASSED
*May 24 19:14:10.504: IKEv2:(SA ID = 1):Get my authentication method
*May 24 19:14:10.504: IKEv2:(SA ID = 1):My authentication method is 'PSK'
*May 24 19:14:10.504: IKEv2:(SA ID = 1):Check for EAP exchange
*May 24 19:14:10.504: IKEv2:(SA ID = 1):Generating IKE_AUTH message
*May 24 19:14:10.504: IKEv2:(SA ID = 1):Constructing IDi payload: '172.16.10.1'
 of type 'IPv4 address'
*May 24 19:14:10.504: IKEv2:(SA ID = 1):ESP Proposal: 1, SPI size: 4
 (IPSec negotiation), 
Num. transforms: 3
   AES-CBC   SHA96   Don't use ESN
*May 24 19:14:10.504: IKEv2:(SA ID = 1):Building packet for encryption.  
Payload contents: 
 VID IDi AUTH SA TSi TSr NOTIFY(INITIAL_CONTACT) NOTIFY(SET_WINDOW_SIZE)
 NOTIFY(ESP_TFC_NO_SUPPORT) NOTIFY(NON_FIRST_FRAGS) 

*May 24 19:14:10.505: IKEv2:(SA ID = 1):Sending Packet
 [To 172.16.10.2:500/From 172.16.10.1:500/VRF i0:f0] 
Initiator SPI : 9FFC38791FFEF212 - Responder SPI : 6CDC17F5B0B10C1A Message id: 1
IKEv2 IKE_AUTH Exchange REQUEST 
Payload contents: 
 ENCR     
 

*May 24 19:14:10.522: IKEv2:(SA ID = 1):Received Packet
 [From 172.16.10.2:500/To 172.16.10.1:500/VRF i0:f0] 
Initiator SPI : 9FFC38791FFEF212 - Responder SPI : 6CDC17F5B0B10C1A Message id: 1
IKEv2 IKE_AUTH Exchange RESPONSE 
Payload contents: 
 IDr AUTH SA TSi TSr NOTIFY(Unknown - 16403) 

*May 24 19:14:10.522: IKEv2:(SA ID = 1):Process auth response notify
*May 24 19:14:10.522: IKEv2:(SA ID = 1):Searching policy based on peer's
 identity '172.16.10.2' of type 'IPv4 address'
*May 24 19:14:10.522: IKEv2:Searching Policy with fvrf 0, local address 172.16.10.1
*May 24 19:14:10.522: IKEv2:Found Policy 'ikev2policy'
*May 24 19:14:10.522: IKEv2:(SA ID = 1):Verify peer's policy
*May 24 19:14:10.522: IKEv2:(SA ID = 1):Peer's policy verified
*May 24 19:14:10.522: IKEv2:(SA ID = 1):Get peer's authentication method
*May 24 19:14:10.522: IKEv2:(SA ID = 1):Peer's authentication method is 'PSK'
*May 24 19:14:10.522: IKEv2:(SA ID = 1):Get peer's preshared key for 172.16.10.2
*May 24 19:14:10.522: IKEv2:(SA ID = 1):Verify peer's authentication data
*May 24 19:14:10.522: IKEv2:(SA ID = 1):Use preshared key for id 172.16.10.2, key len 5
*May 24 19:14:10.522: IKEv2:[IKEv2 -> Crypto Engine] Generate IKEv2 authentication data
*May 24 19:14:10.522: IKEv2:[Crypto Engine -> IKEv2] IKEv2 authentication data
 generation PASSED
*May 24 19:14:10.522: IKEv2:(SA ID = 1):Verification of peer's authenctication data
 PASSED
*May 24 19:14:10.522: IKEv2:(SA ID = 1):Check for EAP exchange
*May 24 19:14:10.522: IKEv2:(SA ID = 1):Processing IKE_AUTH message
*May 24 19:14:10.522: IKEv2:KMI/verify policy/sending to IPSec: 
         prot: 3 txfm: 12 hmac 2 flags 8177 keysize 128 IDB 0x0
*May 24 19:14:10.522: IPSEC(validate_proposal_request): proposal part #1
*May 24 19:14:10.522: IPSEC(validate_proposal_request): proposal part #1,
  (key eng. msg.) INBOUND local= 172.16.10.1:0, remote= 172.16.10.2:0,
    local_proxy= 192.168.1.0/255.255.255.0/256/0,
    remote_proxy= 192.168.2.0/255.255.255.0/256/0,
    protocol= ESP, transform= NONE  (Tunnel), 
    lifedur= 0s and 0kb, 
    spi= 0x0(0), conn_id= 0, keysize= 128, flags= 0x0
*May 24 19:14:10.522: Crypto mapdb : proxy_match
        src addr     : 192.168.1.0
        dst addr     : 192.168.2.0
        protocol     : 0
        src port     : 0
        dst port     : 0
*May 24 19:14:10.522: IKEv2:(SA ID = 1):IKEV2 SA created; inserting SA into database.
 SA lifetime timer (86400 sec) started
*May 24 19:14:10.522: IKEv2:(SA ID = 1):Session with IKE ID PAIR
 (172.16.10.2, 172.16.10.1) is UP
*May 24 19:14:10.522: IKEv2:IKEv2 MIB tunnel started, tunnel index 1
*May 24 19:14:10.522: IKEv2:(SA ID = 1):Load IPSEC key material
*May 24 19:14:10.522: IKEv2:(SA ID = 1):[IKEv2 -> IPsec] Create IPsec SA into
 IPsec database
*May 24 19:14:10.522: IKEv2:(SA ID = 1):Asynchronous request queued

*May 24 19:14:10.522: IKEv2:(SA ID = 1):
*May 24 19:14:10.523: IPSEC(key_engine): got a queue event with 1 KMI message(s)
*May 24 19:14:10.523: Crypto mapdb : proxy_match
        src addr     : 192.168.1.0
       dst addr     : 192.168.2.0
        protocol     : 256
        src port     : 0
        dst port     : 0
*May 24 19:14:10.523: IPSEC(crypto_ipsec_create_ipsec_sas): Map found cmap
*May 24 19:14:10.523: IPSEC(crypto_ipsec_sa_find_ident_head): reconnecting with
 the same proxies and peer 172.16.10.2
*May 24 19:14:10.523: IPSEC(create_sa): sa created,
  (sa) sa_dest= 172.16.10.1, sa_proto= 50, 
    sa_spi= 0xDF405365(3745534821), 
    sa_trans= esp-aes esp-sha-hmac , sa_conn_id= 6
    sa_lifetime(k/sec)= (4608000/3600)
*May 24 19:14:10.523: IPSEC(create_sa): sa created,
  (sa) sa_dest= 172.16.10.2, sa_proto= 50, 
    sa_spi= 0xC0CC116C(3234599276), 
    sa_trans= esp-aes esp-sha-hmac , sa_conn_id= 5
    sa_lifetime(k/sec)= (4608000/3600)
*May 24 19:14:10.523: IPSEC: Expand action denied, notify RP
*May 24 19:14:10.523: IKEv2:(SA ID = 1):[IPsec -> IKEv2] Creation of IPsec
 SA into IPsec database PASSED
The IKEv2 session is up and the IPSec SA that protects traffic between 192.168.1.0/24 and 192.168.2.0/24 has been created.
Cisco IOS: Check IPSec Counters
R1#show crypto session detail 
Crypto session current status

Code: C - IKE Configuration mode, D - Dead Peer Detection     
K - Keepalives, N - NAT-traversal, T - cTCP encapsulation     
X - IKE Extended Authentication, F - IKE Fragmentation

Interface: Ethernet0/0
Uptime: 00:00:09
Session status: UP-ACTIVE     
Peer: 172.16.10.2 port 500 fvrf: (none) ivrf: (none)
      Phase1_id: 172.16.10.2
      Desc: (none)
  IKEv2 SA: local 172.16.10.1/500 remote 172.16.10.2/500 Active 
          Capabilities:(none) connid:1 lifetime:23:59:51
  IPSEC FLOW: permit ip 192.168.1.0/255.255.255.0 192.168.2.0/255.255.255.0 
        Active SAs: 2, origin: crypto map
        Inbound:  #pkts dec'ed 0 drop 0 life (KB/Sec) 4375820/3590
        Outbound: #pkts enc'ed 0 drop 0 life (KB/Sec) 4375820/3590

After 100 packets are sent:
R1#ping 192.168.2.1 source 192.168.1.1 repeat 100
Type escape sequence to abort.
Sending 100, 100-byte ICMP Echos to 192.168.2.1, timeout is 2 seconds:
Packet sent with a source address of 192.168.1.1 
!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
Success rate is 100 percent (100/100), round-trip min/avg/max = 1/4/5 ms
R1#


R1#show crypto session detail                      
Crypto session current status

Code: C - IKE Configuration mode, D - Dead Peer Detection     
K - Keepalives, N - NAT-traversal, T - cTCP encapsulation     
X - IKE Extended Authentication, F - IKE Fragmentation

Interface: Ethernet0/0
Uptime: 00:00:15
Session status: UP-ACTIVE     
Peer: 172.16.10.2 port 500 fvrf: (none) ivrf: (none)
      Phase1_id: 172.16.10.2
      Desc: (none)
  IKEv2 SA: local 172.16.10.1/500 remote 172.16.10.2/500 Active 
          Capabilities:(none) connid:1 lifetime:23:59:45
  IPSEC FLOW: permit ip 192.168.1.0/255.255.255.0 192.168.2.0/255.255.255.0 
        Active SAs: 2, origin: crypto map
        Inbound:  #pkts dec'ed 100 drop 0 life (KB/Sec) 4375803/3585
        Outbound: #pkts enc'ed 100 drop 0 life (KB/Sec) 4375803/3585

The counter has increased by 100.

Cisco IOS: Verify IKEv2 and IPSec Parameters

Cisco IOS has very nice statistics/details for the IKEv2 session:

R1#show crypto ikev2 sa detailed 
 IPv4 Crypto IKEv2  SA 

Tunnel-id Local                 Remote                fvrf/ivrf            Status 
1         172.16.10.1/500       172.16.10.2/500       none/none            READY  
      Encr: AES-CBC, keysize: 128, Hash: SHA96, DH Grp:5, Auth sign: PSK, Auth verify: PSK
      Life/Active Time: 86400/152 sec
      CE id: 1019, Session-id: 3
      Status Description: Negotiation done
      Local spi: 9FFC38791FFEF212       Remote spi: 6CDC17F5B0B10C1A
      Local id: 172.16.10.1
      Remote id: 172.16.10.2
      Local req msg id:  2              Remote req msg id:  0         
      Local next msg id: 2              Remote next msg id: 0         
      Local req queued:  2              Remote req queued:  0         
      Local window:      5              Remote window:      1         
      DPD configured for 0 seconds, retry 0
      Fragmentation not configured.
      Extended Authentication not configured.
      NAT-T is not detected  
      Cisco Trust Security SGT is disabled
      Initiator of SA : Yes

 IPv6 Crypto IKEv2  SA 


R1#show crypto ipsec sa 

interface: Ethernet0/0
    Crypto map tag: cmap, local addr 172.16.10.1

   protected vrf: (none)
   local  ident (addr/mask/prot/port): (192.168.1.0/255.255.255.0/0/0)
   remote ident (addr/mask/prot/port): (192.168.2.0/255.255.255.0/0/0)
   current_peer 172.16.10.2 port 500
     PERMIT, flags={origin_is_acl,}
    #pkts encaps: 100, #pkts encrypt: 100, #pkts digest: 100
    #pkts decaps: 100, #pkts decrypt: 100, #pkts verify: 100
    #pkts compressed: 0, #pkts decompressed: 0
    #pkts not compressed: 0, #pkts compr. failed: 0
    #pkts not decompressed: 0, #pkts decompress failed: 0
    #send errors 0, #recv errors 0

     local crypto endpt.: 172.16.10.1, remote crypto endpt.: 172.16.10.2
     plaintext mtu 1438, path mtu 1500, ip mtu 1500, ip mtu idb Ethernet0/0
     current outbound spi: 0xC0CC116C(3234599276)
     PFS (Y/N): N, DH group: none

     inbound esp sas:
      spi: 0xDF405365(3745534821)
        transform: esp-aes esp-sha-hmac ,
        in use settings ={Tunnel, }
        conn id: 6, flow_id: SW:6, sibling_flags 80000040, crypto map: cmap
        sa timing: remaining key lifetime (k/sec): (4375803/3442)
        IV size: 16 bytes
        replay detection support: Y
        Status: ACTIVE(ACTIVE)

     inbound ah sas:

     inbound pcp sas:

     outbound esp sas:
      spi: 0xC0CC116C(3234599276)
        transform: esp-aes esp-sha-hmac ,
        in use settings ={Tunnel, }
        conn id: 5, flow_id: SW:5, sibling_flags 80000040, crypto map: cmap
        sa timing: remaining key lifetime (k/sec): (4375803/3442)
        IV size: 16 bytes
        replay detection support: Y
        Status: ACTIVE(ACTIVE)

     outbound ah sas:
          
     outbound pcp sas:    

strongSwan: Tunnel Establishment

May 24 21:14:10 localhost charon: 08[NET] received packet: from 172.16.10.1[500] 
to 172.16.10.2[500] (400 bytes)
May 24 21:14:10 localhost charon: 08[ENC] parsed IKE_SA_INIT request 0
 [ SA KE No V V N(NATD_S_IP) N(NATD_D_IP) ]
May 24 21:14:10 localhost charon: 08[ENC] received unknown vendor
 ID: 43:49:53:43:4f:2d:44:45:4c:45:54:45:2d:52:45:41:53:4f:4e
May 24 21:14:10 localhost charon: 08[ENC] received unknown vendor ID:
 46:4c:45:58:56:50:4e:2d:53:55:50:50:4f:52:54:45:44
May 24 21:14:10 localhost charon: 08[IKE] 172.16.10.1 is initiating an IKE_SA
May 24 21:14:10 localhost charon: 08[IKE] 172.16.10.1 is initiating an IKE_SA
May 24 21:14:10 localhost charon: 08[ENC] generating IKE_SA_INIT response 0
 [ SA KE No N(NATD_S_IP) N(NATD_D_IP) N(MULT_AUTH) ]
May 24 21:14:10 localhost charon: 08[NET] sending packet: from 172.16.10.2[500]
 to 172.16.10.1[500] (376 bytes)
May 24 21:14:10 localhost charon: 07[NET] received packet: from 172.16.10.1[500]
 to 172.16.10.2[500] (284 bytes)
May 24 21:14:10 localhost charon: 07[ENC] parsed IKE_AUTH request 1 [ V IDi AUTH
 SA TSi TSr N(INIT_CONTACT) N(SET_WINSIZE) N(ESP_TFC_PAD_N) N(NON_FIRST_FRAG) ]
May 24 21:14:10 localhost charon: 07[CFG] looking for peer configs matching
 172.16.10.2[%any]...172.16.10.1[172.16.10.1]
May 24 21:14:10 localhost charon: 07[CFG] selected peer config 'ciscoios'
May 24 21:14:10 localhost charon: 07[IKE] authentication of '172.16.10.1' with
 pre-shared key successful
May 24 21:14:10 localhost charon: 07[IKE] received ESP_TFC_PADDING_NOT_SUPPORTED,
 not using ESPv3 TFC padding
May 24 21:14:10 localhost charon: 07[IKE] authentication of '172.16.10.2' (myself)
 with pre-shared key
May 24 21:14:10 localhost charon: 07[IKE] IKE_SA ciscoios[2] established between
 172.16.10.2[172.16.10.2]...172.16.10.1[172.16.10.1]
May 24 21:14:10 localhost charon: 07[IKE] IKE_SA ciscoios[2] established between
 172.16.10.2[172.16.10.2]...172.16.10.1[172.16.10.1]
May 24 21:14:10 localhost charon: 07[IKE] scheduling reauthentication in 3247s
May 24 21:14:10 localhost charon: 07[IKE] maximum IKE_SA lifetime 3427s
May 24 21:14:10 localhost charon: 07[IKE] CHILD_SA ciscoios{2} established with
 SPIs c0cc116c_i df405365_o and TS 192.168.2.0/24 === 192.168.1.0/24 
May 24 21:14:10 localhost charon: 07[IKE] CHILD_SA ciscoios{2} established with
 SPIs c0cc116c_i df405365_o and TS 192.168.2.0/24 === 192.168.1.0/24 
May 24 21:14:10 localhost vpn: + 172.16.10.1 192.168.1.0/24 == 172.16.10.1 --
 172.16.10.2 == 192.168.2.0/24

The tunnel establishment details look a bit similar to IKEv1.

strongSwan: Verify IPSec Connection Status

pluton ~ # ipsec statusall
Status of IKE charon daemon (strongSwan 5.0.4, Linux 3.2.12-gentoo, x86_64):
  uptime: 2 minutes, since May 24 21:13:27 2013
  malloc: sbrk 393216, mmap 0, used 274864, free 118352
  worker threads: 8 of 16 idle, 7/1/0/0 working, job queue: 0/0/0/0, scheduled: 4
  loaded plugins: charon mysql sqlite aes des sha1 sha2 md5 random nonce x509
 revocation constraints pubkey pkcs1 pkcs8 pgp dnskey pem openssl gcrypt
 fips-prf gmp xcbc cmac hmac attr kernel-netlink resolve socket-default
 stroke updown eap-identity eap-sim eap-aka eap-aka-3gpp2 eap-simaka-pseudonym
 eap-simaka-reauth eap-md5 eap-gtc eap-mschapv2 eap-radius xauth-generic
Listening IP addresses:
  10.0.0.100
  192.168.10.1
  192.168.2.1
  172.16.10.2
Connections:
    ciscoios:  172.16.10.2...172.16.10.1  IKEv2
    ciscoios:   local:  [172.16.10.2] uses pre-shared key authentication
    ciscoios:   remote: [172.16.10.1] uses pre-shared key authentication
    ciscoios:   child:  192.168.2.0/24 === 192.168.1.0/24 TUNNEL
Security Associations (1 up, 0 connecting):
    ciscoios[2]: ESTABLISHED 116 seconds ago, 172.16.10.2[172.16.10.2]...
172.16.10.1[172.16.10.1]
    ciscoios[2]: IKEv2 SPIs: 12f2fe1f7938fc9f_i 1a0cb1b0f517dc6c_r*,
 pre-shared key reauthentication in 52 minutes
    ciscoios[2]: IKE proposal: AES_CBC_128/HMAC_SHA1_96/PRF_HMAC_SHA1/MODP_1536
    ciscoios{2}:  INSTALLED, TUNNEL, ESP SPIs: c0cc116c_i df405365_o
    ciscoios{2}:  AES_CBC_128/HMAC_SHA1_96, 10000 bytes_i (100 pkts, 102s ago),
 10000 bytes_o (100 pkts, 102s ago), rekeying in 12 minutes
    ciscoios{2}:   192.168.2.0/24 === 192.168.1.0/24 
strongSwan: Verify IPSec Policy
pluton ~ # ip -s xfrm policy
src 192.168.1.0/24 dst 192.168.2.0/24 uid 0
        dir fwd action allow index 1154 priority 1859 share any flag  (0x00000000)
        lifetime config:
          limit: soft (INF)(bytes), hard (INF)(bytes)
          limit: soft (INF)(packets), hard (INF)(packets)
          expire add: soft 0(sec), hard 0(sec)
          expire use: soft 0(sec), hard 0(sec)
        lifetime current:
          0(bytes), 0(packets)
          add 2013-05-24 21:14:10 use -
        tmpl src 172.16.10.1 dst 172.16.10.2
                proto esp spi 0x00000000(0) reqid 2(0x00000002) mode tunnel
                level required share any 
                enc-mask ffffffff auth-mask ffffffff comp-mask ffffffff
src 192.168.1.0/24 dst 192.168.2.0/24 uid 0
        dir in action allow index 1144 priority 1859 share any flag  (0x00000000)
        lifetime config:
          limit: soft (INF)(bytes), hard (INF)(bytes)
          limit: soft (INF)(packets), hard (INF)(packets)
          expire add: soft 0(sec), hard 0(sec)
          expire use: soft 0(sec), hard 0(sec)
        lifetime current:
          0(bytes), 0(packets)
          add 2013-05-24 21:14:10 use 2013-05-24 21:14:23
        tmpl src 172.16.10.1 dst 172.16.10.2
                proto esp spi 0x00000000(0) reqid 2(0x00000002) mode tunnel
                level required share any 
                enc-mask ffffffff auth-mask ffffffff comp-mask ffffffff
src 192.168.2.0/24 dst 192.168.1.0/24 uid 0
        dir out action allow index 1137 priority 1859 share any flag  (0x00000000)
        lifetime config:
          limit: soft (INF)(bytes), hard (INF)(bytes)
          limit: soft (INF)(packets), hard (INF)(packets)
          expire add: soft 0(sec), hard 0(sec)
          expire use: soft 0(sec), hard 0(sec)
        lifetime current:
          0(bytes), 0(packets)
          add 2013-05-24 21:14:10 use 2013-05-24 21:14:23
        tmpl src 172.16.10.2 dst 172.16.10.1
                proto esp spi 0x00000000(0) reqid 2(0x00000002) mode tunnel
                level required share any 
                enc-mask ffffffff auth-mask ffffffff comp-mask ffffffff


Was this answer helpful?

« Back