Understanding IOS IPSec and IKE debugs - IKEv1 Main Mode.

[Marcin Latosiewicz]

• 1. Introduction
• 2. Core issue
• 3. Scenario
• 3.1 Debugs used.
• 3.2 IOS router configuration.
• 4. Debugging.
• 4.1 IOS responder side
• 4.2 IOS router - initiator.
• 4.2.1 Main mode message 1 (MM1) - Initial contact.
• 5.0 Further reading.

Disclaimer: This is best   effort work only, it may be (and probably is) not 100% accurate. This  work  will be corrected as corrective feedback is received.

1. Introduction

This  document will attempt to describe how to understand debugs on IOS when main mode and pre shared key (PSK) is being used.

How to translate certain debug lines into configuration.

What will not be discussed:

- passing traffic after tunnel has been established.

- basic concepts of IPSec or IKE.

2. Core issue

IKE and IPSec debugs tend to get cryptic, TAC will very often use them to understand where a problem with IPSec VPN tunnel establishment is located.

3. Scenario

Main  mode is typically used between Lan-to-Lan tunnels or in case of remote  access (ezvpn) when certificates are used for authentication.

Those debugs are from IOS device running 15.2(1)T release.

Two main scenarios will be described:

1. IOS initiator side

2. IOS responder side

In this case I will be establishing a VTI based tunnel between two sites, based on IPv6.

3.1 Debugs used.

debug crypto isakmp

debug crypto ipsec

debug crypto kmi

3.2 IOS router configuration.

Crypto configuration:

crypto isakmp policy 10

authentication pre-share

crypto isakmp key cisco address ipv6 ::/0

crypto ipsec transform-set TRA esp-aes esp-sha-hmac

mode transport

crypto ipsec profile PRO

set transform-set TRA

interface Tunnel23

ip address 192.168.23.2 255.255.255.0

ipv6 address FE80::23:2 link-local

tunnel source Ethernet0/0

tunnel mode ipsec ipv6

tunnel destination 2001:DB8::3

tunnel protection ipsec profile PRO

other side:

crypto isakmp policy 10

authentication pre-share

crypto isakmp key cisco address ipv6 ::/0

crypto ipsec transform-set TRA esp-aes esp-sha-hmac

mode transport

crypto ipsec profile PRO

set transform-set TRA

interface Tunnel23

ip address 192.168.23.3 255.255.255.0

ipv6 address FE80::23:3 link-local

tunnel source Ethernet0/0

tunnel mode ipsec ipv6

tunnel destination 2001:DB8::2

tunnel protection ipsec profile PRO

4. Debugging.

4.1 IOS responder side

4.1.1 Main Mode message 1  (MM1)

Includes:

Initial proposal for IKE:

- encryption

- hashing

- DH group

- lifetime

*Sep 21 08:33:43.377: ISAKMP (0): received packet from 2001:DB8::2 dport 500 sport 500 Global (N) NEW SA

*Sep 21 08:33:43.377: ISAKMP: Created a peer struct for 2001:DB8::2, peer port 500

*Sep 21 08:33:43.377: ISAKMP: New peer created peer = 0x8E45588 peer_handle = 0x8000000A

*Sep 21 08:33:43.377: ISAKMP: Locking peer struct 0x8E45588, refcount 1 for crypto_isakmp_process_block

*Sep 21 08:33:43.377: ISAKMP: local port 500, remote port 500

*Sep 21 08:33:43.377: ISAKMP:(0):insert sa successfully sa = 6D12A00

*Sep 21 08:33:43.377: ISAKMP:(0):Input = IKE_MESG_FROM_PEER, IKE_MM_EXCH

*Sep 21 08:33:43.377: ISAKMP:(0):Old State = IKE_READY  New State = IKE_R_MM1

*Sep 21 08:33:43.377: ISAKMP:(0): processing SA payload. message ID = 0

*Sep 21 08:33:43.377: ISAKMP:(0):found peer pre-shared key matching 2001:DB8::2

*Sep 21 08:33:43.377: ISAKMP:(0): local preshared key found

*Sep 21 08:33:43.377: ISAKMP : Scanning profiles for xauth ...

*Sep 21 08:33:43.377: ISAKMP:(0):Checking ISAKMP transform 1 against priority 10 policy

*Sep 21 08:33:43.377: ISAKMP:      encryption DES-CBC

*Sep 21 08:33:43.377: ISAKMP:      hash SHA

*Sep 21 08:33:43.377: ISAKMP:      default group 1

*Sep 21 08:33:43.377: ISAKMP:      auth pre-share

*Sep 21 08:33:43.377: ISAKMP:      life type in seconds

*Sep 21 08:33:43.377: ISAKMP:      life duration (VPI) of  0x0 0x1 0x51 0x80

*Sep 21 08:33:43.377: ISAKMP:(0):atts are acceptable. Next payload is 0

*Sep 21 08:33:43.377: ISAKMP:(0):Acceptable atts:actual life: 0

*Sep 21 08:33:43.377: ISAKMP:(0):Acceptable atts:life: 0

*Sep 21 08:33:43.377: ISAKMP:(0):Fill atts in sa vpi_length:4

*Sep 21 08:33:43.377: ISAKMP:(0):Fill atts in sa life_in_seconds:86400

*Sep 21 08:33:43.377: ISAKMP:(0):Returning Actual lifetime: 86400

*Sep 21 08:33:43.377: ISAKMP:(0)::Started lifetime timer: 86400.

*Sep 21 08:33:43.377: ISAKMP:(0):Input = IKE_MESG_INTERNAL, IKE_PROCESS_MAIN_MODE

*Sep 21 08:33:43.377: ISAKMP:(0):Old State = IKE_R_MM1  New State = IKE_R_MM1

Related configuration:

crypto isakmp policy 10

authentication pre-share

4.1.2 Main Mode message 2  (MM2) - sending our reply.

*Sep 21 08:33:43.377: ISAKMP:(0): sending packet to 2001:DB8::2 my_port 500 peer_port 500 (R) MM_SA_SETUP

*Sep 21 08:33:43.377: ISAKMP:(0):Sending an IKE IPv6 Packet.

*Sep 21 08:33:43.377: ISAKMP:(0):Input = IKE_MESG_INTERNAL, IKE_PROCESS_COMPLETE

*Sep 21 08:33:43.377: ISAKMP:(0):Old State = IKE_R_MM1  New State = IKE_R_MM2

4.1.3 Main Mode message 3  (MM3)

Includes:

- NAT discovery

- Diffie-Hellman (DH) exchange part one.

*Sep 21 08:33:43.381: ISAKMP (0): received packet from 2001:DB8::2 dport 500 sport 500 Global (R) MM_SA_SETUP

*Sep 21 08:33:43.381: ISAKMP:(0):Input = IKE_MESG_FROM_PEER, IKE_MM_EXCH

*Sep 21 08:33:43.381: ISAKMP:(0):Old State = IKE_R_MM2  New State = IKE_R_MM3

*Sep 21 08:33:43.381: ISAKMP:(0): processing KE payload. message ID = 0

*Sep 21 08:33:43.393: ISAKMP:(0): processing NONCE payload. message ID = 0

*Sep 21 08:33:43.393: ISAKMP:(0):found peer pre-shared key matching 2001:DB8::2

*Sep 21 08:33:43.393: ISAKMP:(1011): processing vendor id payload

*Sep 21 08:33:43.393: ISAKMP:(1011): vendor ID is DPD

*Sep 21 08:33:43.393: ISAKMP:(1011): processing vendor id payload

*Sep 21 08:33:43.393: ISAKMP:(1011): speaking to another IOS box!

*Sep 21 08:33:43.393: ISAKMP:(1011): processing vendor id payload

*Sep 21 08:33:43.393: ISAKMP:(1011): vendor ID seems Unity/DPD but major 0 mismatch

*Sep 21 08:33:43.393: ISAKMP:(1011): vendor ID is XAUTH

*Sep 21 08:33:43.393: ISAKMP:(1011):Input = IKE_MESG_INTERNAL, IKE_PROCESS_MAIN_MODE

*Sep 21 08:33:43.393: ISAKMP:(1011):Old State = IKE_R_MM3  New State = IKE_R_MM3

4.1.4 Main Mode message 4  (MM4)

Includes:

NAT detection payload

Continuation of DH exchange.

*Sep 21 08:33:43.405: ISAKMP:(1011): sending packet to 2001:DB8::2 my_port 500 peer_port 500 (R) MM_KEY_EXCH

*Sep 21 08:33:43.405: ISAKMP:(1011):Sending an IKE IPv6 Packet.

*Sep 21 08:33:43.405: ISAKMP:(1011):Input = IKE_MESG_INTERNAL, IKE_PROCESS_COMPLETE

*Sep 21 08:33:43.405: ISAKMP:(1011):Old State = IKE_R_MM3  New State = IKE_R_MM4

4.1.5 Main Mode message 5  (MM5) - initiator send it's identity.

Includes:

- Local identity information.

- Key

*Sep 21 08:33:43.425: ISAKMP (1011): received packet from 2001:DB8::2 dport 500 sport 500 Global (R) MM_KEY_EXCH

*Sep 21 08:33:43.425: ISAKMP:(1011):Input = IKE_MESG_FROM_PEER, IKE_MM_EXCH

*Sep 21 08:33:43.425: ISAKMP:(1011):Old State = IKE_R_MM4  New State = IKE_R_MM5

*Sep 21 08:33:43.425: ISAKMP:(1011): processing ID payload. message ID = 0

*Sep 21 08:33:43.425: ISAKMP (1011): ID payload

        next-payload : 8

        type         : 5

        address      : 2001:DB8::2

        protocol     : 17

        port         : 500

        length       : 24

*Sep 21 08:33:43.425: ISAKMP:(0):: peer matches *none* of the profiles

*Sep 21 08:33:43.425: ISAKMP:(1011): processing HASH payload. message ID = 0

*Sep 21 08:33:43.425: ISAKMP:(1011): processing NOTIFY INITIAL_CONTACT protocol 1

        spi 0, message ID = 0, sa = 0x6D12A00

*Sep 21 08:33:43.425: ISAKMP:(1011):SA authentication status:

        authenticated

*Sep 21 08:33:43.425: ISAKMP:(1011):SA has been authenticated with 2001:DB8::2

*Sep 21 08:33:43.425: ISAKMP:(1011):SA authentication status:

        authenticated

*Sep 21 08:33:43.425: ISAKMP:(1011): Process initial contact,

bring down existing phase 1 and 2 SA's with local 2001:DB8::3 remote 2001:DB8::2 remote port 500

*Sep 21 08:33:43.425: ISAKMP: Trying to insert a peer 2001:DB8::3/2001:DB8::2/500/,  and inserted successfully 8E45588.

*Sep 21 08:33:43.425: ISAKMP:(1011):Input = IKE_MESG_INTERNAL, IKE_PROCESS_MAIN_MODE

*Sep 21 08:33:43.425: ISAKMP:(1011):Old State = IKE_R_MM5  New State = IKE_R_MM5

Related configuration:

4.1.6 Main Mode message 6  (MM6) - responder sends it's identity. Phase 1 completion.

Includes:

- Remote identity sent from peer

- Final decision regarding tunnel group to pick.

*Sep 21 08:33:43.425: IPSEC(key_engine): got a queue event with 1 KMI message(s)

*Sep 21 08:33:43.425: ISAKMP:(1011):SA is doing pre-shared key authentication using id type ID_IPV6_ADDR

*Sep 21 08:33:43.425: ISAKMP (1011): ID payload

        next-payload : 8

        type         : 5

        address      : 2001:DB8::3

        protocol     : 17

        port         : 500

        length       : 24

*Sep 21 08:33:43.425: ISAKMP:(1011):Total payload length: 24

*Sep 21 08:33:43.425: ISAKMP:(1011): sending packet to 2001:DB8::2 my_port 500 peer_port 500 (R) MM_KEY_EXCH

*Sep 21 08:33:43.425: ISAKMP:(1011):Sending an IKE IPv6 Packet.

*Sep 21 08:33:43.425: ISAKMP:(1011):Input = IKE_MESG_INTERNAL, IKE_PROCESS_COMPLETE

*Sep 21 08:33:43.425: ISAKMP:(1011):Old State = IKE_R_MM5  New State = IKE_P1_COMPLET

Related configuration:

crypto isakmp identity ...

4.1.7 Quick mode message 1  (QM1)

*Sep 21 08:33:43.433: ISAKMP (1011): received packet from 2001:DB8::2 dport 500 sport 500 Global (R) QM_IDLE

*Sep 21 08:33:43.433: ISAKMP: set new node 1371333358 to QM_IDLE

*Sep 21 08:33:43.433: ISAKMP:(1011): processing HASH payload. message ID = 1371333358

*Sep 21 08:33:43.433: ISAKMP:(1011): processing SA payload. message ID = 1371333358

*Sep 21 08:33:43.433: ISAKMP:(1011):Checking IPSec proposal 1

*Sep 21 08:33:43.433: ISAKMP: transform 1, ESP_AES

*Sep 21 08:33:43.433: ISAKMP:   attributes in transform:

*Sep 21 08:33:43.433: ISAKMP:      encaps is 1 (Tunnel)

*Sep 21 08:33:43.433: ISAKMP:      SA life type in seconds

*Sep 21 08:33:43.433: ISAKMP:      SA life duration (basic) of 3600

*Sep 21 08:33:43.433: ISAKMP:      SA life type in kilobytes

*Sep 21 08:33:43.433: ISAKMP:      SA life duration (VPI) of  0x0 0x46 0x50 0x0

*Sep 21 08:33:43.433: ISAKMP:      authenticator is HMAC-SHA

*Sep 21 08:33:43.433: ISAKMP:      key length is 128

*Sep 21 08:33:43.433: ISAKMP:(1011):atts are acceptable.

*Sep 21 08:33:43.433: IPSEC(validate_proposal_request): proposal part #1

*Sep 21 08:33:43.433: IPSEC(validate_proposal_request): proposal part #1,

  (key eng. msg.) INBOUND local= 2001:DB8::3:0, remote= 2001:DB8::2:0,

    local_proxy= ::/0/256/0,

    remote_proxy= ::/0/256/0,

    protocol= ESP, transform= NONE  (Tunnel),

    lifedur= 0s and 0kb,

    spi= 0x0(0), conn_id= 0, keysize= 128, flags= 0x0

*Sep 21 08:33:43.433: ISAKMP:(1011): processing NONCE payload. message ID = 1371333358

*Sep 21 08:33:43.433: ISAKMP:(1011): processing ID payload. message ID = 1371333358

*Sep 21 08:33:43.433: ISAKMP:(1011): processing ID payload. message ID = 1371333358

*Sep 21 08:33:43.433: ISAKMP:(1011):QM Responder gets spi

*Sep 21 08:33:43.433: ISAKMP:(1011):Node 1371333358, Input = IKE_MESG_FROM_PEER, IKE_QM_EXCH

*Sep 21 08:33:43.433: ISAKMP:(1011):Old State = IKE_QM_READY  New State = IKE_QM_SPI_STARVE

Relevant configuration:

tunnel mode ipsec ipv6

4.1.8 Quick Mode Message 2  (QM2)

Includes:

Remote end sends it parameters.

We pick shorter out of the two proposed phase 2 lifetimes.

*Sep 21 08:33:43.433: ISAKMP:(1011): sending packet to 2001:DB8::2 my_port 500 peer_port 500 (R) QM_IDLE

*Sep 21 08:33:43.433: ISAKMP:(1011):Sending an IKE IPv6 Packet.

*Sep 21 08:33:43.433: ISAKMP:(1011):Node 1371333358, Input = IKE_MESG_INTERNAL, IKE_GOT_SPI

*Sep 21 08:33:43.433: ISAKMP:(1011):Old State = IKE_QM_SPI_STARVE  New State = IKE_QM_R_QM2

*Sep 21 08:33:43.437: IPSEC(key_engine): got a queue event with 1 KMI message(s)

R3(config-if)#

*Sep 21 08:33:43.437: IPSEC(crypto_ipsec_create_ipsec_sas): Map found Tunnel23-head-0

*Sep 21 08:33:43.437: IPSEC(crypto_ipsec_sa_find_ident_head): reconnecting with the same proxies and peer 2001:DB8::2

*Sep 21 08:33:43.437: IPSEC(create_sa): sa created,

  (sa) sa_dest= 2001:DB8::3, sa_proto= 50,

    sa_spi= 0x221A7153(572158291),

    sa_trans= esp-aes esp-sha-hmac , sa_conn_id= 305

    sa_lifetime(k/sec)= (4608000/3532)

*Sep 21 08:33:43.437: IPSEC(create_sa): sa created,

  (sa) sa_dest= 2001:DB8::2, sa_proto= 50,

    sa_spi= 0x45F16A9A(1173449370),

    sa_trans= esp-aes esp-sha-hmac , sa_conn_id= 306

    sa_lifetime(k/sec)= (4608000/3532)

Relevant configuration:

crypto ipsec transform-set TRA esp-aes esp-sha-hmac

mode transport

crypto ipsec profile PRO

set transform-set TRA

interface tunnel23

tunnel mode ipsec ipv6

tunnel protection ipsec profile PRO

4.1.9 Quick Mode Message 3 (QM3) - phase two should be complete and tunnel interface up.

*Sep 21 08:33:43.437: %LINEPROTO-5-UPDOWN: Line protocol on Interface Tunnel23, changed state to up

*Sep 21 08:33:43.437: ISAKMP (1011): received packet from 2001:DB8::2 dport 500 sport 500 Global (R) QM_IDLE

*Sep 21 08:33:43.437: ISAKMP:(1011):deleting node 1371333358 error FALSE reason "QM done (await)"

*Sep 21 08:33:43.437: ISAKMP:(1011):Node 1371333358, Input = IKE_MESG_FROM_PEER, IKE_QM_EXCH

*Sep 21 08:33:43.437: ISAKMP:(1011):Old State = IKE_QM_R_QM2  New State = IKE_QM_PHASE2_COMPLETE

*Sep 21 08:33:43.437: IPSEC(key_engine): got a queue event with 1 KMI message(s)

*Sep 21 08:33:43.437: IPSEC(key_engine_enable_outbound): rec'd enable notify from ISAKMP

4.2 IOS router - initiator.

4.2.1 Main mode message 1 (MM1) - Initial contact.

Includes:

- Vendor IDs (VID)

- Capacities

- Phase 1 proposals

- IKE sa.

- IPsec already creates a template for SAs.

Sep 21 08:33:43.245: %CRYPTO-6-ISAKMP_ON_OFF: ISAKMP is ON

*Sep 21 08:33:43.245: IPSEC(sa ident sadb root initialize created IPv6 ACL %s): Tunnel23-head-0-65537-Tunnel23-head-0-ACL-6-IPSECV6-ACL

*Sep 21 08:33:43.245: IPSEC(recalculate_mtu): reset sadb_root 79E82A8 mtu to 1500

*Sep 21 08:33:43.245: IPSEC(adjust_mtu): adjusting ident ip mtu from 1460 to 1500,

  (identity) local= 2001:DB8::2:0, remote= 2001:DB8::3:0,

    local_proxy= ::/0/256/0,

    remote_proxy= ::/0/256/0

*Sep 21 08:33:43.245: IPSEC(adjust_mtu): adjusting path mtu from 1460 to 1500,

  (identity) local= 2001:DB8::2:0, remote= 2001:DB8::3:0,

    local_proxy= ::/0/256/0,

    remote_proxy= ::/0/256/0

*Sep 21 08:33:43.245: IPSEC(sa_request): ,

  (key eng. msg.) OUTBOUND local= 2001:DB8::2:500, remote= 2001:DB8::3:500,

    local_proxy= ::/0/256/0,

    remote_proxy= ::/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

*Sep 21 08:33:43.245: ISAKMP:(0): SA request profile is (NULL)

*Sep 21 08:33:43.245: ISAKMP: Created a peer struct for 2001:DB8::3, peer port 500

*Sep 21 08:33:43.245: ISAKMP: New peer created peer = 0x9344BE8 peer_handle = 0x80000008

*Sep 21 08:33:43.245: ISAKMP: Locking peer struct 0x9344BE8, refcount 1 for isakmp_initiator

*Sep 21 08:33:43.245: ISAKMP: local port 500, remote port 500

*Sep 21 08:33:43.245: ISAKMP: set new node 0 to QM_IDLE

*Sep 21 08:33:43.245: ISAKMP:(0):insert sa successfully sa = 944C840

*Sep 21 08:33:43.245: ISAKMP:(0):Can not start Aggressive mode, trying Main mode.

*Sep 21 08:33:43.245: ISAKMP:(0):found peer pre-shared key matching 2001:DB8::3

*Sep 21 08:33:43.245: ISAKMP:(0):Input = IKE_MESG_FROM_IPSEC, IKE_SA_REQ_MM

*Sep 21 08:33:43.245: ISAKMP:(0):Old State = IKE_READY  New State = IKE_I_MM1

*Sep 21 08:33:43.245: ISAKMP:(0): beginning Main Mode exchange

*Sep 21 08:33:43.245: ISAKMP:(0): sending packet to 2001:DB8::3 my_port 500 peer_port 500 (I) MM_NO_STATE

*Sep 21 08:33:43.245: ISAKMP:(0):Sending an IKE IPv6 Packet.

Relevant configuration:

crypto isakmp policy 10

authentication pre-share

4.2.2 Main mode message 2 (MM2) - reply to initial contact.

Includes:

- Peer chooses isakmp policy to use.

- IKE SA

*Sep 21 08:33:43.249: ISAKMP (0): received packet from 2001:DB8::3 dport 500 sport 500 Global (I) MM_NO_STATE

*Sep 21 08:33:43.249: ISAKMP:(0):Input = IKE_MESG_FROM_PEER, IKE_MM_EXCH

*Sep 21 08:33:43.249: ISAKMP:(0):Old State = IKE_I_MM1  New State = IKE_I_MM2

*Sep 21 08:33:43.249: ISAKMP:(0): processing SA payload. message ID = 0

*Sep 21 08:33:43.249: ISAKMP:(0):found peer pre-shared key matching 2001:DB8::3

*Sep 21 08:33:43.249: ISAKMP:(0): local preshared key found

*Sep 21 08:33:43.249: ISAKMP : Scanning profiles for xauth ...

*Sep 21 08:33:43.249: ISAKMP:(0):Checking ISAKMP transform 1 against priority 10 policy

*Sep 21 08:33:43.249: ISAKMP:      encryption DES-CBC

*Sep 21 08:33:43.249: ISAKMP:      hash SHA

*Sep 21 08:33:43.249: ISAKMP:      default group 1

*Sep 21 08:33:43.249: ISAKMP:      auth pre-share

*Sep 21 08:33:43.249: ISAKMP:      life type in seconds

*Sep 21 08:33:43.249: ISAKMP:      life duration (VPI) of  0x0 0x1 0x51 0x80

*Sep 21 08:33:43.249: ISAKMP:(0):atts are acceptable. Next payload is 0

*Sep 21 08:33:43.249: ISAKMP:(0):Acceptable atts:actual life: 0

*Sep 21 08:33:43.249: ISAKMP:(0):Acceptable atts:life: 0

*Sep 21 08:33:43.249: ISAKMP:(0):Fill atts in sa vpi_length:4

*Sep 21 08:33:43.249: ISAKMP:(0):Fill atts in sa life_in_seconds:86400

*Sep 21 08:33:43.249: ISAKMP:(0):Returning Actual lifetime: 86400

*Sep 21 08:33:43.249: ISAKMP:(0)::Started lifetime timer: 86400.

*Sep 21 08:33:43.249: ISAKMP:(0):Input = IKE_MESG_INTERNAL, IKE_PROCESS_MAIN_MODE

*Sep 21 08:33:43.249: ISAKMP:(0):Old State = IKE_I_MM2  New State = IKE_I_MM2

4.2.3 Main mode message 3 (MM3) - NAT discovery and Diffie-Hellman exchange.

Includes:

- NAT discovery payload and hash.

- DH exchange initiation.

(- DPD support)

*Sep 21 08:33:43.249: ISAKMP:(0): sending packet to 2001:DB8::3 my_port 500 peer_port 500 (I) MM_SA_SETUP

*Sep 21 08:33:43.249: ISAKMP:(0):Sending an IKE IPv6 Packet.

*Sep 21 08:33:43.249: ISAKMP:(0):Input = IKE_MESG_INTERNAL, IKE_PROCESS_COMPLETE

*Sep 21 08:33:43.249: ISAKMP:(0):Old State = IKE_I_MM2  New State = IKE_I_MM3

4.2.4 Main mode message 4 (MM4) - NAT discovery and Diffie-Hellman exchange

Includes:

- NAT discovery payload

- DH exchange initiation.

- additional VIDs (DPD, Unity support)

- we know we're talking to another IOS device.

Sep 21 08:33:43.273: ISAKMP (0): received packet from 2001:DB8::3 dport 500 sport 500 Global (I) MM_SA_SETUP

*Sep 21 08:33:43.273: ISAKMP:(0):Input = IKE_MESG_FROM_PEER, IKE_MM_EXCH

*Sep 21 08:33:43.273: ISAKMP:(0):Old State = IKE_I_MM3  New State = IKE_I_MM4

*Sep 21 08:33:43.273: ISAKMP:(0): processing KE payload. message ID = 0

*Sep 21 08:33:43.281: ISAKMP:(0): processing NONCE payload. message ID = 0

*Sep 21 08:33:43.281: ISAKMP:(0):found peer pre-shared key matching 2001:DB8::3

*Sep 21 08:33:43.281: ISAKMP:(1011): processing vendor id payload

*Sep 21 08:33:43.281: ISAKMP:(1011): vendor ID is Unity

*Sep 21 08:33:43.281: ISAKMP:(1011): processing vendor id payload

*Sep 21 08:33:43.281: ISAKMP:(1011): vendor ID is DPD

*Sep 21 08:33:43.281: ISAKMP:(1011): processing vendor id payload

*Sep 21 08:33:43.281: ISAKMP:(1011): speaking to another IOS box!

*Sep 21 08:33:43.281: ISAKMP:(1011):Input = IKE_MESG_INTERNAL, IKE_PROCESS_MAIN_MODE

*Sep 21 08:33:43.281: ISAKMP:(1011):Old State = IKE_I_MM4  New State = IKE_I_MM4

4.2.5 Main mode message 5 (MM5) - we're sending our identity

Includes:

- Remote peer identity (ID)

*Sep 21 08:33:43.293: ISAKMP:(1011):Send initial contact

*Sep 21 08:33:43.293: ISAKMP:(1011):SA is doing pre-shared key authentication using id type ID_IPV6_ADDR

*Sep 21 08:33:43.293: ISAKMP (1011): ID payload

        next-payload : 8

        type         : 5

        address      : 2001:DB8::2

        protocol     : 17

        port         : 500

        length       : 24

*Sep 21 08:33:43.293: ISAKMP:(1011):Total payload length: 24

*Sep 21 08:33:43.293: ISAKMP:(1011): sending packet to 2001:DB8::3 my_port 500 peer_port 500 (I) MM_KEY_EXCH

*Sep 21 08:33:43.293: ISAKMP:(1011):Sending an IKE IPv6 Packet.

*Sep 21 08:33:43.293: ISAKMP:(1011):Input = IKE_MESG_INTERNAL, IKE_PROCESS_COMPLETE

*Sep 21 08:33:43.293: ISAKMP:(1011):Old State = IKE_I_MM4  New State = IKE_I_MM5

Relevant configuration:

crypto isakmp identity ...

4.2.6 Main mode message 6 (MM6) - remote peer identity, Phase 1 is established.

Includes:

- Rekey times started

- remote identity (in this case an address)

- decission to land on a profile.

*Sep 21 08:33:43.297: ISAKMP (1011): received packet from 2001:DB8::3 dport 500 sport 500 Global (I) MM_KEY_EXCH

*Sep 21 08:33:43.297: ISAKMP:(1011): processing ID payload. message ID = 0

*Sep 21 08:33:43.297: ISAKMP (1011): ID payload

        next-payload : 8

        type         : 5

        address      : 2001:DB8::3

        protocol     : 17

        port         : 500

        length       : 24

*Sep 21 08:33:43.297: ISAKMP:(0):: peer matches *none* of the profiles

*Sep 21 08:33:43.297: ISAKMP:(1011): processing HASH payload. message ID = 0

*Sep 21 08:33:43.297: ISAKMP:(1011):SA authentication status:

        authenticated

*Sep 21 08:33:43.297: ISAKMP:(1011):SA has been authenticated with 2001:DB8::3

*Sep 21 08:33:43.297: ISAKMP: Trying to insert a peer 2001:DB8::2/2001:DB8::3/500/,  and inserted successfully 9344BE8.

*Sep 21 08:33:43.297: ISAKMP:(1011):Input = IKE_MESG_FROM_PEER, IKE_MM_EXCH

*Sep 21 08:33:43.297: ISAKMP:(1011):Old State = IKE_I_MM5  New State = IKE_I_MM6

*Sep 21 08:33:43.297: ISAKMP:(1011):Input = IKE_MESG_INTERNAL, IKE_PROCESS_MAIN_MODE

*Sep 21 08:33:43.297: ISAKMP:(1011):Old State = IKE_I_MM6  New State = IKE_I_MM6

*Sep 21 08:33:43.301: ISAKMP:(1011):Input = IKE_MESG_INTERNAL, IKE_PROCESS_COMPLETE

*Sep 21 08:33:43.301: ISAKMP:(1011):Old State = IKE_I_MM6  New State = IKE_P1_COMPLETE

Relevant configuration

crypto isakmp identity ...

4.2.7 Quick mode message 1 (QM1) - peer starts phase 2.

Include:

- remote and local proxy IDs.

- Transform set(s)

*Sep 21 08:33:43.301: ISAKMP:(1011):beginning Quick Mode exchange, M-ID of 1371333358

*Sep 21 08:33:43.301: ISAKMP:(1011):QM Initiator gets spi

*Sep 21 08:33:43.301: ISAKMP:(1011): sending packet to 2001:DB8::3 my_port 500 peer_port 500 (I) QM_IDLE

*Sep 21 08:33:43.301: ISAKMP:(1011):Sending an IKE IPv6 Packet.

*Sep 21 08:33:43.301: ISAKMP:(1011):Node 1371333358, Input = IKE_MESG_INTERNAL, IKE_INIT_QM

*Sep 21 08:33:43.301: ISAKMP:(1011):Old State = IKE_QM_READY  New State = IKE_QM_I_QM1

*Sep 21 08:33:43.301: ISAKMP:(1011):Input = IKE_MESG_INTERNAL, IKE_PHASE1_COMPLETE

*Sep 21 08:33:43.301: ISAKMP:(1011):Old State = IKE_P1_COMPLETE  New State = IKE_P1_COMPLETE

Relevant configuration:

crypto ipsec transform-set TRA esp-aes esp-sha-hmac

mode transport

crypto ipsec profile PRO

set transform-set TRA

4.2.8 Quick mode message 2 (QM2)

Includes:

- Confirmation of proxy identities.

- Tunnel type.

- PFS settings

*Sep 21 08:33:43.305: ISAKMP (1011): received packet from 2001:DB8::3 dport 500 sport 500 Global (I) QM_IDLE

*Sep 21 08:33:43.305: ISAKMP:(1011): processing HASH payload. message ID = 1371333358

*Sep 21 08:33:43.305: ISAKMP:(1011): processing SA payload. message ID = 1371333358

*Sep 21 08:33:43.305: ISAKMP:(1011):Checking IPSec proposal 1

*Sep 21 08:33:43.305: ISAKMP: transform 1, ESP_AES

*Sep 21 08:33:43.305: ISAKMP:   attributes in transform:

*Sep 21 08:33:43.305: ISAKMP:      encaps is 1 (Tunnel)

*Sep 21 08:33:43.305: ISAKMP:      SA life type in seconds

*Sep 21 08:33:43.305: ISAKMP:      SA life duration (basic) of 3600

*Sep 21 08:33:43.305: ISAKMP:      SA life type in kilobytes

*Sep 21 08:33:43.305: ISAKMP:      SA life duration (VPI) of  0x0 0x46 0x50 0x0

*Sep 21 08:33:43.305: ISAKMP:      authenticator is HMAC-SHA

*Sep 21 08:33:43.305: ISAKMP:      key length is 128

*Sep 21 08:33:43.305: ISAKMP:(1011):atts are acceptable.

*Sep 21 08:33:43.305: IPSEC(validate_proposal_request): proposal part #1

*Sep 21 08:33:43.305: IPSEC(validate_proposal_request): proposal part #1,

  (key eng. msg.) INBOUND local= 2001:DB8::2:0, remote= 2001:DB8::3:0,

    local_proxy= ::/0/256/0,

    remote_proxy= ::/0/256/0,

    protocol= ESP, transform= NONE  (Tunnel),

    lifedur= 0s and 0kb,

    spi= 0x0(0), conn_id= 0, keysize= 128, flags= 0x0

*Sep 21 08:33:43.305: ISAKMP:(1011): processing NONCE payload. message ID = 1371333358

*Sep 21 08:33:43.305: ISAKMP:(1011): processing ID payload. message ID = 1371333358

*Sep 21 08:33:43.305: ISAKMP:(1011): processing ID payload. message ID = 1371333358

Relevant configuration:

crypto ipsec transform-set TRA esp-aes esp-sha-hmac

mode transport

crypto ipsec profile PRO

set transform-set TRA

interface tunnel23

tunnel mode ipsec ipv6

tunnel protection ipsec profile PRO

4.2.9 Quick mode message 3 (QM3) - Phase 2 establishment.

Includes:

- Setting of SPIs to pass traffic.

*Sep 21 08:33:43.305: ISAKMP:(1011):Sending an IKE IPv6 Packet.

*Sep 21 08:33:43.305: ISAKMP:(1011):deleting node 1371333358 error FALSE reason "No Error"

*Sep 21 08:33:43.305: ISAKMP:(1011):Node 1371333358, Input = IKE_MESG_FROM_PEER, IKE_QM_EXCH

*Sep 21 08:33:43.305: ISAKMP:(1011):Old State = IKE_QM_I_QM1  New State = IKE_QM_PHASE2_COMPLETE

*Sep 21 08:33:43.305: IPSEC(key_engine): got a queue event with 1 KMI message(s)

*Sep 21 08:33:43.305: IPSEC(crypto_ipsec_create_ipsec_sas): Map found Tunnel23-head-0

*Sep 21 08:33:43.305: IPSEC(crypto_ipsec_sa_find_ident_head): reconnecting with the same proxies and peer 2001:DB8::3

*Sep 21 08:33:43.305: IPSEC(create_sa): sa created,

  (sa) sa_dest= 2001:DB8::2, sa_proto= 50,

    sa_spi= 0x45F16A9A(1173449370),

    sa_trans= esp-aes esp-sha-hmac , sa_conn_id= 305

    sa_lifetime(k/sec)= (4608000/3439)

*Sep 21 08:33:43.305: IPSEC(create_sa): sa created,

  (sa) sa_dest= 2001:DB8::3, sa_proto= 50,

    sa_spi= 0x221A7153(572158291),

    sa_trans= esp-aes esp-sha-hmac , sa_conn_id= 306

    sa_lifetime(k/sec)= (4608000/3439)

R2(config-if)#

*Sep 21 08:33:43.309: %LINEPROTO-5-UPDOWN: Line protocol on Interface Tunnel23, changed state to up

Tunnel verification.

sh crypto ipsec sa

interface: Tunnel23

    Crypto map tag: Tunnel23-head-0, local addr 2001:DB8::2

   protected vrf: (none)

   local  ident (addr/mask/prot/port): (::/0/0/0)

   remote ident (addr/mask/prot/port): (::/0/0/0)

   current_peer 2001:DB8::3 port 500

     PERMIT, flags={origin_is_acl,}

    #pkts encaps: 4, #pkts encrypt: 4, #pkts digest: 4

    #pkts decaps: 4, #pkts decrypt: 4, #pkts verify: 4

    #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.: 2001:DB8::2,

     remote crypto endpt.: 2001:DB8::3

     path mtu 1500, ipv6 mtu 1500, ipv6 mtu idb Ethernet0/0

     current outbound spi: 0x221A7153(572158291)

     PFS (Y/N): N, DH group: none

     inbound esp sas:

      spi: 0x45F16A9A(1173449370)

        transform: esp-aes esp-sha-hmac ,

        in use settings ={Tunnel, }

        conn id: 305, flow_id: SW:305, sibling_flags 80000041, crypto map: Tunnel23-head-0

        sa timing: remaining key lifetime (k/sec): (4183789/3408)

        IV size: 16 bytes

        replay detection support: Y

        Status: ACTIVE

     inbound ah sas:

     inbound pcp sas:

     outbound esp sas:

      spi: 0x221A7153(572158291)

        transform: esp-aes esp-sha-hmac ,

        in use settings ={Tunnel, }

        conn id: 306, flow_id: SW:306, sibling_flags 80000041, crypto map: Tunnel23-head-0

        sa timing: remaining key lifetime (k/sec): (4183790/3408)

        IV size: 16 bytes

        replay detection support: Y

        Status: ACTIVE

R2(config-if)#do ping fe80::23:3

Output Interface: tunnel23

Type escape sequence to abort.

Sending 5, 100-byte ICMP Echos to FE80::23:3, timeout is 2 seconds:

Packet sent with a source address of FE80::23:2%Tunnel23

!!!!!

Success rate is 100 percent (5/5), round-trip min/avg/max = 8/11/20 ms

R2(config-if)#do sh crypto ipsec sa | i caps|ident

   local  ident (addr/mask/prot/port): (::/0/0/0)

   remote ident (addr/mask/prot/port): (::/0/0/0)

    #pkts encaps: 9, #pkts encrypt: 9, #pkts digest: 9

    #pkts decaps: 9, #pkts decrypt: 9, #pkts verify: 9

Tunnel is up and passing traffic.

5.0 Further reading.

A good place to start is wikipedia article on IPSec.

Standard and references contains a lot of useful information:

http://en.wikipedia.org/wiki/IPsec

Regarding aggressive mode on ASA

https://supportforums.cisco.com/docs/DOC-13715

Regarding aggressive mode on IOS:

https://supportforums.cisco.com/docs/DOC-17021

Regarding main mode on ASA

https://supportforums.cisco.com/docs/DOC-14044

[samchakr]

This is Awesome! Can you do a similar piece for IKEv2.

Thanks a Lot!

[Marcin Latosiewicz]

Thanks for the feedback.

We're in process of moving those to CCO, and yes IKEv2 is on to do list.

However we're also working on readbility of debugs with development, I think it would make sense to create a document like this once we have things finilized.

[CiscoPurpleBelt]

I have a router responder stuck on R_MM2 phase 1 MM_SA_SETUP. ANy help?