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ASA 5505 L2TP/IPSEC 'idle' after 'phase 1 complete'

atapidriver
Level 1
Level 1

Hello all,

I have an issue with configuring L2TP/IPSEC connection between ASA 5505 and Forticlient VPN.

I have managed to successfully connect using native Windows 10 L2TP/IPSEC client, however, unable to perform it using Forticlient VPN.

 

Debug output is almost the same for both clients, but Forticlient stops at:

 

Mar 05 13:25:14 [IKEv1]Group = DefaultRAGroup, IP = xxx, PHASE 1 COMPLETED
Mar 05 13:25:14 [IKEv1]IP = xxx, Keep-alive type for this connection: None
Mar 05 13:25:14 [IKEv1]IP = xxx, Keep-alives configured on but peer does not support keep-alives (type = None)
Mar 05 13:25:14 [IKEv1 DEBUG]Group = DefaultRAGroup, IP = xxx, Starting P1 rekey timer: 82080 seconds.

 

IKEv1 SAs:

Active SA: 1
Rekey SA: 0 (A tunnel will report 1 Active and 1 Rekey SA during rekey)
Total IKE SA: 1

1 IKE Peer: xxx
Type : user Role : responder
Rekey : no State : MM_ACTIVE
Encrypt : 3des Hash : SHA
Auth : preshared Lifetime: 86400
Lifetime Remaining: 85998

 

 

What can I check more? I am currently out of suggestions.

Tested with Windows 10, Sever 2016, with firewall disabled.

 

Client computer, as well as ASA, are not behind any NAT.

 

Debugging as follows:

 

debug crypto ipsec enabled at level 255
debug crypto ikev1 enabled at level 255
debug crypto ike-common enabled at level 255

 

Client has just 'connecting' state.

1 Accepted Solution

Accepted Solutions

atapidriver
Level 1
Level 1

Sorry I forgot to put an answer here.

It seems that FortiClient has just 'raw' IPSEC tunnel functionality, and not L2TP/IPSEC, so that's why it did not work :S

 

I may assume topic as solved.

View solution in original post

3 Replies 3

Rahul Govindan
VIP Alumni
VIP Alumni

Not sure if this will even work compatibility-wise. But from the looks of it, the debugs stop after the ASA sends back Main mode message 6 (Phase1). Forticlient has to start Phase 2 for the ASA to do something. What does the debug on Forticlient say?

I have managed to take different (i.e. older) version of Forticlient (5 vs 6) which actually allows to turn debug mode on. So, I have managed to check two things:

 

1) Client side logs and problem with xauth

2) Switching to aggressive mode

 

Ad.1

 

As I have mentioned, I have checked logs and client side.

 

3/6/2019 9:20:24 AM Debug VPN HASH computed:

3/6/2019 9:20:24 AM Debug VPN 9f7200e3 3d31a872 14aecea9 05733cc1 55d5eda7

3/6/2019 9:20:24 AM Debug VPN HASH for PSK validated.

3/6/2019 9:20:24 AM Debug VPN peer's ID:

3/6/2019 9:20:24 AM Debug VPN 01110000 b2ff2a0e

3/6/2019 9:20:24 AM Debug VPN ===

3/6/2019 9:20:24 AM Debug VPN ISAKMP-SA established clientAddr[500]-routerAddr[500]
spi:8243bc412c8b6033:62a4b23f51445745

3/6/2019 9:20:24 AM Debug VPN ===

3/6/2019 9:20:26 AM Debug VPN peer has not completed Xauth exchange

3/6/2019 9:20:26 AM Debug VPN CHKPH1THERE: no established ph1 handler found

3/6/2019 9:20:27 AM Debug VPN peer has not completed Xauth exchange

3/6/2019 9:20:27 AM Debug VPN CHKPH1THERE: no established ph1 handler found

 

It seems that there are problems with xauth - however I cannot find what exact problem it is - disabling xauth explictly in ASA configuration does not change anything. I  have disabled it by:

 

tunnel-group DefaultRAGroup ipsec-attributes

ikev1 user-authentication none

However, it breaks native Windows VPN  client so I reverted this change back to defaults i.e:

ikev1 user-authentication xauth

 

Due to lack of ideas, I decided to try

 

Ad. 2) Aggresive mode.

 

Here I am mislead by non acceptable proposals. Dunno why it gives such error.

I have defined two policies:

 

crypto ikev1 policy 10
authentication pre-share
encryption 3des
hash sha
group 2
lifetime 86400
crypto ikev1 policy 20
authentication pre-share
encryption aes
hash sha
group 2
lifetime 86400

 

Connection debug seems to confirm it:

 

RECV PACKET from clientAddr
ISAKMP Header
Initiator COOKIE: a6 29 1e d2 82 38 d0 35
Responder COOKIE: 00 00 00 00 00 00 00 00
Next Payload: Security Association
Version: 1.0
Exchange Type: Aggressive Mode
Flags: (none)
MessageID: 00000000
Length: 450
Payload Security Association
Next Payload: Key Exchange
Reserved: 00
Payload Length: 96
DOI: IPsec
Situation:(SIT_IDENTITY_ONLY)
Payload Proposal
Next Payload: None
Reserved: 00
Payload Length: 84
Proposal #: 1
Protocol-Id: PROTO_ISAKMP
SPI Size: 0
# of transforms: 2
Payload Transform
Next Payload: Transform
Reserved: 00
Payload Length: 36
Transform #: 1
Transform-Id: KEY_IKE
Reserved2: 0000
Life Type: seconds
Life Duration (Hex): 00 01 51 80
Encryption Algorithm: 3DES-CBC
Authentication Method: Preshared key
Hash Algorithm: SHA1
Group Description: Group 2
Payload Transform
Next Payload: None
Reserved: 00
Payload Length: 40
Transform #: 2
Transform-Id: KEY_IKE
Reserved2: 0000
Life Type: seconds
Life Duration (Hex): 00 01 51 80
Encryption Algorithm: AES-CBC
Key Length: 128
Authentication Method: Preshared key
Hash Algorithm: SHA1
Group Description: Group 2
Payload Key Exchange
Next Payload: Nonce
Reserved: 00
Payload Length: 132
Data:

(...)

 

 

but in the end it tells that:

 

 

Mar 06 18:12:20 [IKEv1]IP = clientAddr, IKE_DECODE RECEIVED Message (msgid=0) with payloads : HDR + SA (1)
+ KE (4) + NONCE (10) + ID (5) + VENDOR (13) + VENDOR (13) + VENDOR (13) + VENDOR (13) + VENDOR (13) + VENDOR
(13) + VENDOR (13) + VENDOR (13) + NONE (0) total length : 450
Mar 06 18:12:20 [IKEv1 DEBUG]IP = clientAddr, processing SA payload
Mar 06 18:12:20 [IKEv1 DEBUG]IP = clientAddr, processing ke payload
Mar 06 18:12:20 [IKEv1 DEBUG]IP = clientAddr, processing ISA_KE payload
Mar 06 18:12:20 [IKEv1 DEBUG]IP = clientAddr, processing nonce payload
Mar 06 18:12:20 [IKEv1 DEBUG]IP = clientAddr, processing ID payload
Mar 06 18:12:20 [IKEv1 DECODE]IP = clientAddr, ID_FQDN ID received, len 14
0000: 44656661 756C7452 4147726F 7570 DefaultRAGroup


Mar 06 18:12:20 [IKEv1 DEBUG]IP = clientAddr, processing VID payload
Mar 06 18:12:20 [IKEv1 DEBUG]IP = clientAddr, Received Cisco Unity client VID
Mar 06 18:12:20 [IKEv1 DEBUG]IP = clientAddr, processing VID payload
Mar 06 18:12:20 [IKEv1 DEBUG]IP = clientAddr, Received NAT-Traversal RFC VID
Mar 06 18:12:20 [IKEv1 DEBUG]IP = clientAddr, processing VID payload
Mar 06 18:12:20 [IKEv1 DEBUG]IP = clientAddr, processing VID payload
Mar 06 18:12:20 [IKEv1 DEBUG]IP = clientAddr, Received NAT-Traversal ver 02 VID
Mar 06 18:12:20 [IKEv1 DEBUG]IP = clientAddr, processing VID payload
Mar 06 18:12:20 [IKEv1 DEBUG]IP = clientAddr, Received xauth V6 VID
Mar 06 18:12:20 [IKEv1 DEBUG]IP = clientAddr, processing VID payload
Mar 06 18:12:20 [IKEv1 DEBUG]IP = clientAddr, Received DPD VID
Mar 06 18:12:20 [IKEv1 DEBUG]IP = clientAddr, processing VID payload
Mar 06 18:12:20 [IKEv1 DEBUG]IP = clientAddr, processing VID payload
Mar 06 18:12:20 [IKEv1]IP = clientAddr, Connection landed on tunnel_group DefaultRAGroup
Mar 06 18:12:20 [IKEv1 DEBUG]Group = DefaultRAGroup, IP = clientAddr, processing IKE SA payload
Mar 06 18:12:20 [IKEv1]IP = clientAddr, IKE_DECODE SENDING Message (msgid=0) with payloads : HDR + NOTIFY
(11) + NONE (0) total length : 136
Mar 06 18:12:20 [IKEv1 DEBUG]Group = DefaultRAGroup, IP = clientAddr, All SA proposals found unacceptable
Mar 06 18:12:20 [IKEv1]IP = clientAddr, All IKE SA proposals found unacceptable!
Mar 06 18:12:20 [IKEv1 DEBUG]Group = DefaultRAGroup, IP = clientAddr, IKE AM Responder FSM error history
(struct &0xc868ac48) <state>, <event>: AM_DONE, EV_ERROR-->AM_BLD_MSG2, EV_PROCESS_SA-->AM_BLD_MSG2,
EV_GROUP_LOOKUP-->AM_BLD_MSG2, EV_PROCESS_MSG-->AM_BLD_MSG2, EV_CREATE_TMR-->AM_START, EV_RCV_MSG-->AM_START,
EV_START_AM-->AM_START, EV_START_AM
Mar 06 18:12:20 [IKEv1 DEBUG]Group = DefaultRAGroup, IP = clientAddr, IKE SA AM:84212e9b terminating:
flags 0x0100c001, refcnt 0, tuncnt 0
Mar 06 18:12:20 [IKEv1 DEBUG]Group = DefaultRAGroup, IP = clientAddr, sending delete/delete with reason message

 

 

Client side logs, it just seems to break when ASA does not find any acceptable proposals:

 

3/6/2019 9:36:33 AM Debug VPN begin Aggressive mode.

3/6/2019 9:36:33 AM Debug VPN new cookie: 6f312b96f65ab7ae

3/6/2019 9:36:33 AM Debug VPN use ID type of IPv4_address

3/6/2019 9:36:33 AM Debug VPN compute DH's private.

3/6/2019 9:36:33 AM Debug VPN (some encoded data)

3/6/2019 9:36:33 AM Debug VPN compute DH's public.

3/6/2019 9:36:33 AM Debug VPN (some encoded data)

3/6/2019 9:36:33 AM Debug VPN authmethod is pre-shared key

3/6/2019 9:36:33 AM Debug VPN add payload of len 92, next type 4

3/6/2019 9:36:33 AM Debug VPN add payload of len 128, next type 10

3/6/2019 9:36:33 AM Debug VPN add payload of len 16, next type 5

3/6/2019 9:36:33 AM Debug VPN add payload of len 8, next type 13

3/6/2019 9:36:33 AM Debug VPN add payload of len 16, next type 13

3/6/2019 9:36:32 AM Debug VPN (repeated 3 times in last 0 sec) add payload of len 16, next type 13

3/6/2019 9:36:33 AM Debug VPN add payload of len 8, next type 13

3/6/2019 9:36:33 AM Debug VPN add payload of len 16, next type 13

3/6/2019 9:36:32 AM Debug VPN (repeated 1 times in last 0 sec) add payload of len 16, next type 13

3/6/2019 9:36:33 AM Debug VPN add payload of len 16, next type 0

3/6/2019 9:36:33 AM Debug VPN 440 bytes from clientAddr[500] to routerAddr[500]

3/6/2019 9:36:33 AM Debug VPN sockname 0.0.0.0[500]

3/6/2019 9:36:33 AM Debug VPN send packet from clientAddr[500]

3/6/2019 9:36:33 AM Debug VPN send packet to routerAddr[500]

3/6/2019 9:36:33 AM Debug VPN 1 times of 440 bytes message will be sent to routerAddr[500]

3/6/2019 9:36:33 AM Debug VPN (some encoded data)

3/6/2019 9:36:33 AM Debug VPN resend phase1 packet 6f312b96f65ab7ae:0000000000000000

3/6/2019 9:36:33 AM Information VPN id=96566 msg="negotiation information, loc_ip=clientAddr loc_port=500 rem_ip=routerAddr rem_port=500 out_if=0 vpn_tunnel=test action=negotiate init=local mode=aggressive stage=1 dir=outbound status=success Initiator: sent routerAddr aggressive mode message #1
(OK)" vpntunnel=test vpntype=ipsec

3/6/2019 9:36:33 AM Debug VPN ===

3/6/2019 9:36:33 AM Debug VPN 136 bytes message received from routerAddr[500] to clientAddr[500]

3/6/2019 9:36:33 AM Debug VPN (some encoded data)

3/6/2019 9:36:33 AM Debug VPN receive Information.

3/6/2019 9:36:33 AM Debug VPN reject the packet, received unexpecting payload type 0.

3/6/2019 9:36:34 AM Debug VPN CHKPH1THERE: no established ph1 handler found3/6/2019 9:36:34 AM Debug VPN (repeated 1 times in last 1 sec) CHKPH1THERE: no established ph1 handler found

 

 

That's all I have managed to check so far.

atapidriver
Level 1
Level 1

Sorry I forgot to put an answer here.

It seems that FortiClient has just 'raw' IPSEC tunnel functionality, and not L2TP/IPSEC, so that's why it did not work :S

 

I may assume topic as solved.