IKEv2: IOS (9) and MacOSX (10.11) disconnect after 480 Sec

joerg · Apr 26, 2016, 8:15 AM

I try to setup an IKEv2-VPN for all platforms (Windows, Mac, Linux, Android, IOS). Everything works fine so far. The only issue i have is IOS (9) and MacOSX (10.11) (native clients) disconnect after 480 sec (8Min). I have the same behavior with different versions (2.2.6, 2.3, 2.3.1-DEVELOPMENT). Does anyone have similar issues or an idea why this happens?

Regards,

Jörg

Log:

Apr 26 09:31:44 charon 12[KNL] <con1|2>querying SAD entry with SPI c5ee17d6
Apr 26 09:31:44 charon 12[IKE] <con1|2>IKE_SA deleted
Apr 26 09:31:44 charon 12[IKE] <con1|2>IKE_SA con1[2] state change: ESTABLISHED => DELETING
Apr 26 09:31:44 charon 12[IKE] <con1|2>deleting IKE_SA con1[2] between XX.XX.XX.XX[vpn-test.test.tld]…XX.XX.XX.XX[XX.XX.XX.XX]
Apr 26 09:31:44 charon 12[IKE] <con1|2>received DELETE for IKE_SA con1[2]
Apr 26 09:31:44 charon 12[ENC] <con1|2>parsed INFORMATIONAL request 7 [ D ]
Apr 26 09:31:44 charon 12[NET] <con1|2>received packet: from XX.XX.XX.XX[4500] to XX.XX.XX.XX[4500] (68 bytes)
Apr 26 09:31:44 charon 12[MGR] IKE_SA con1[2] successfully checked out
Apr 26 09:31:44 charon 12[MGR] checkout IKEv2 SA by message with SPIs ecde9fba7e6f72f8_i 834280eec438a4c8_r
Apr 26 09:31:44 charon 15[MGR] <con1|2>checkin of IKE_SA successful
Apr 26 09:31:44 charon 15[MGR] <con1|2>checkin IKE_SA con1[2]
Apr 26 09:31:44 charon 15[NET] <con1|2>sending packet: from XX.XX.XX.XX[4500] to XX.XX.XX.XX[4500] (68 bytes)
Apr 26 09:31:44 charon 15[ENC] <con1|2>generating CREATE_CHILD_SA response 6 [ N(NO_PROP) ]
Apr 26 09:31:44 charon 15[IKE] <con1|3>IKE_SA con1[3] state change: CONNECTING => DESTROYING
Apr 26 09:31:44 charon 15[IKE] <con1|2>applying DH public value failed
Apr 26 09:31:44 charon 15[ENC] <con1|2>invalid DH public value size (256 bytes) for MODP_1024
Apr 26 09:31:44 charon 15[LIB] <con1|2>size of DH secret exponent: 1023 bits

Config:

<phase1><ikeid>1</ikeid>
<iketype>ikev2</iketype>
<interface>wan</interface>
<mobile><protocol>inet</protocol>
<myid_type>fqdn</myid_type>
<myid_data>vpn-test.test.tld</myid_data>
<peerid_type>any</peerid_type>
<peerid_data><encryption-algorithm><name>3des</name></encryption-algorithm>
<hash-algorithm>sha1</hash-algorithm>
<dhgroup>2</dhgroup>
<lifetime>28800</lifetime>
<pre-shared-key><private-key><certref>57173f204c549</certref>
<caref><authentication_method>eap-mschapv2</authentication_method>

<nat_traversal>on</nat_traversal>
<mobike>off</mobike>
<dpd_delay>10</dpd_delay>
<dpd_maxfail>5</dpd_maxfail></caref></private-key></pre-shared-key></peerid_data></mobile></phase1>
<phase2><ikeid>1</ikeid>
<uniqid>56fbb06abd4f6</uniqid>
<mode>tunnel</mode>
<reqid>1</reqid>
<localid><type>network</type>

<netbits>0</netbits></localid>
<remoteid><type>mobile</type></remoteid>
<protocol>esp</protocol>
<encryption-algorithm-option><name>aes</name>
<keylen>auto</keylen></encryption-algorithm-option>
<encryption-algorithm-option><name>3des</name></encryption-algorithm-option>
<hash-algorithm-option>hmac_sha1</hash-algorithm-option>
<hash-algorithm-option>hmac_sha256</hash-algorithm-option>
<pfsgroup>0</pfsgroup>
<lifetime>3600</lifetime></phase2>
<uniqueids>never</uniqueids></con1|2></con1|2></con1|2></con1|3></con1|2></con1|2></con1|2></con1|2></con1|2></con1|2></con1|2></con1|2></con1|2></con1|2></con1|2>

jimp · Apr 27, 2016, 5:00 PM

Apr 26 09:31:44 charon 12[IKE] <con1|2>received DELETE for IKE_SA con1[2]</con1|2>

The client is sending the disconnect, check the client side.

I've left one connected on OS X for hours before without issue.

ohwell · Apr 28, 2016, 4:58 AM

I just got mine working. It was breaking because iOS rekeys every 480 seconds - the proposal wasn't being excepted even though it worked when the tunnels came up. Here's my working config which tunnels IPv4 and IPv6:

<ipsec><client><enable><user_source>Local Database</user_source>
<group_source>system</group_source>
<pool_address>x.x.x.x</pool_address>
<pool_netbits>29</pool_netbits>
<pool_address_v6>xxxx:xxxx:xxxx:xxxx::1:0</pool_address_v6>
<pool_netbits_v6>120</pool_netbits_v6>
<dns_domain>example.com</dns_domain>
<dns_server1>x.x.x.x</dns_server1>
<dns_server2>xxxx:xxxx:xxxx:xxxx:xxxx:xxxx:xxxx:xxxx</dns_server2></enable></client>
<logging><dmn>1</dmn>
<mgr>1</mgr>
<ike>1</ike>
<chd>1</chd>
<job>1</job>
<cfg>1</cfg>
<knl>1</knl>
<net>1</net>
<asn>1</asn>
<enc>1</enc>
<imc>1</imc>
<imv>1</imv>
<pts>1</pts>
<tls>1</tls>
<esp>1</esp>
<lib>1</lib></logging>
<uniqueids>yes</uniqueids>
<phase1><ikeid>1</ikeid>
<iketype>ikev2</iketype>
<interface>wan</interface>
<mobile><protocol>inet</protocol>
<myid_type>fqdn</myid_type>
<myid_data>vpn.example.com</myid_data>
<peerid_type>user_fqdn</peerid_type>
<peerid_data>vpn@example.com</peerid_data>
<encryption-algorithm><name>aes</name>
<keylen>256</keylen></encryption-algorithm>
<hash-algorithm>sha256</hash-algorithm>
<dhgroup>14</dhgroup>
<lifetime>28800</lifetime>
<pre-shared-key><private-key><certref>571b1b15b885c</certref>
<caref><authentication_method>eap-mschapv2</authentication_method>

<nat_traversal>on</nat_traversal>
<mobike>on</mobike>
<responderonly><dpd_delay>10</dpd_delay>
<dpd_maxfail>5</dpd_maxfail></responderonly></caref></private-key></pre-shared-key></mobile></phase1>
<phase2><ikeid>1</ikeid>
<uniqid>57131edf92230</uniqid>
<mode>tunnel</mode>
<reqid>1</reqid>
<localid><type>network</type>

<protocol>esp</protocol>
<encryption-algorithm-option><name>aes</name>
<keylen>256</keylen></encryption-algorithm-option>
<hash-algorithm-option>hmac_sha256</hash-algorithm-option>
<pfsgroup>0</pfsgroup>
<lifetime>3600</lifetime></phase2>
<phase2><ikeid>1</ikeid>
<uniqid>571ac29f93916</uniqid>
<mode>tunnel6</mode>
<reqid>2</reqid>
<localid><type>network</type>

<protocol>esp</protocol>
<encryption-algorithm-option><name>aes</name>
<keylen>256</keylen></encryption-algorithm-option>
<hash-algorithm-option>hmac_sha256</hash-algorithm-option>
<pfsgroup>0</pfsgroup>
<lifetime>3600</lifetime></phase2>
<noshuntlaninterfaces><mobilekey><ident>userx</ident>
<type>EAP</type>
<pre-shared-key>secret</pre-shared-key></mobilekey>
<makebeforebreak></makebeforebreak></noshuntlaninterfaces></ipsec>

joerg · Apr 28, 2016, 8:03 AM

Thank you ohwell. Your config works for MacOSX. Unfortunatly Windows (i tested with Windows 10) does actually not support DH-Group 14. All Windows proposals use DH-Group 2 (MODP_1024). It seems that either Windows or Mac works. Linux with strongswan works with both configs, also the strongswan-app on Android…

Apr 28 09:56:34 charon 11[CFG] <28> configured proposals: IKE:AES_CBC_256/HMAC_SHA2_256_128/PRF_HMAC_SHA2_256/MODP_2048
Apr 28 09:56:34 charon 11[CFG] <28> received proposals: IKE:3DES_CBC/HMAC_SHA1_96/PRF_HMAC_SHA1/MODP_1024, IKE:3DES_CBC/HMAC_SHA2_256_128/PRF_HMAC_SHA2_256/MODP_1024, IKE:3DES_CBC/HMAC_SHA2_384_192/PRF_HMAC_SHA2_384/MODP_1024, IKE:AES_CBC_128/HMAC_SHA1_96/PRF_HMAC_SHA1/MODP_1024, IKE:AES_CBC_128/HMAC_SHA2_256_128/PRF_HMAC_SHA2_256/MODP_1024, IKE:AES_CBC_128/HMAC_SHA2_384_192/PRF_HMAC_SHA2_384/MODP_1024, IKE:AES_CBC_192/HMAC_SHA1_96/PRF_HMAC_SHA1/MODP_1024, IKE:AES_CBC_192/HMAC_SHA2_256_128/PRF_HMAC_SHA2_256/MODP_1024, IKE:AES_CBC_192/HMAC_SHA2_384_192/PRF_HMAC_SHA2_384/MODP_1024, IKE:AES_CBC_256/HMAC_SHA1_96/PRF_HMAC_SHA1/MODP_1024, IKE:AES_CBC_256/HMAC_SHA2_256_128/PRF_HMAC_SHA2_256/MODP_1024, IKE:AES_CBC_256/HMAC_SHA2_384_192/PRF_HMAC_SHA2_384/MODP_1024

ohwell · Apr 28, 2016, 2:58 PM

Take a look at (at least) section 2.2.2.2 of http://download.microsoft.com/download/A/9/F/A9FD7E2D-023B-4925-A62F-58A7F1A6BD47/Microsoft%20Windows%208%20Windows%20Server%202012%20Supplemental%20Admin%20Guidance%20IPsec%20VPN%20Client.docx

I haven't tested this.

joerg · May 4, 2016, 7:20 AM

Thank you ohwell, works fine with Windows 10.

I hope Apple will fix the rekeying for DH Group 2, although DH Group 14 is more secure. With DH Group 2 there is no need for registry-hacks, Apple-profiles etc.

epionier · May 15, 2016, 1:11 PM

Here is a working configuration for IKEv2 MS-CHAP V2 for iOS / OS X / Windows 10 and Android (StrongSwanClient (could not test native client):

1. Add DWORD in Windows Registry with the value 1 according to the post of ohwell (Article chapter 2.2.2.2)

2. Use this encryption for the connection:

Phase 1: AES 256 + SHA256 + DH14
Phase 2: AES 256 + SHA256 + DH Off

Hope this helps someone. DH Group for Phase 2 is in my opinion not absolutely necessary but Group 14 should now work as well.

viniciusferrao · Jun 28, 2016, 3:45 AM

I've some additional issues even after following the section 2.2.2.2 of the document posted.

Windows 10 client does not accept SHA256 on Phase 2. Only SHA1.

07[CFG] <con1|141> received proposals: ESP:AES_CBC_256/HMAC_SHA1_96/NO_EXT_SEQ, ESP:3DES_CBC/HMAC_SHA1_96/NO_EXT_SEQ
07[CFG] <con1|141> configured proposals: ESP:AES_CBC_256/HMAC_SHA2_256_128/NO_EXT_SEQ
07[IKE] <con1|141> no acceptable proposal found</con1|141></con1|141></con1|141>

To solve this I just enabled SHA1 too in the Phase 2. After this the connection works flawlessly, but the routes aren't published.

I need to manually put the route information on the Windows 10 machine with: "route add network/mask ip-address-of-vpn-connection"

Anyone with the same issue?

On OS X everything works fine.

chris88g4 · Apr 11, 2017, 7:21 PM

Hello guys, as i am having the same problem, where can i find this config in order to change it?