[Openswan Users] Site-to-site VPN with openswan

Roel van Meer roel.vanmeer at bokxing.nl
Wed Aug 29 05:29:50 EDT 2012


Jakub Sobczak writes:

> Each time I changed something I did:
> 
>    ipsec auto --delete conn
>    ipsec auto --add conn
>    ipsec auto --up conn

This reloads the connection config, but not the shared secrets.

> But it seems that it has failed to work. After this command:
> 
>    ipsec auto --rereadsecrets
> 
> I think it has negotiated the first phase, but there seems to be a problem 
> with the second phase. 

Do you have any logs of openswan? E.g. the output of:

ipsec auto --delete conn
ipsec auto --add conn
ipsec auto --up conn

or recent content of the log file you posted before..

Regards,

Roel

> 
> 
> 
>    11:01:19.533205 IP remote-ip > my-ip.500: isakmp: phase 1 I ident
>    11:01:19.533365 IP my-ip.500 > remote-ip: isakmp: phase 1 R ident
>    11:01:20.127518 IP remote-ip > my-ip.500: isakmp: phase 1 I ident
>    11:01:20.128536 IP my-ip.500 > remote-ip: isakmp: phase 1 R ident
>    11:01:20.210036 IP remote-ip > my-ip.500: isakmp: phase 1 I ident[E]
>    11:01:20.210213 IP my-ip.500 > remote-ip: isakmp: phase 1 R ident[E]
>    11:01:20.303975 IP remote-ip > my-ip.500: isakmp: phase 2/others I 
>    oakley-quick[E]
>    11:01:20.304176 IP my-ip.500 > remote-ip: isakmp: phase 2/others R 
>    inf[E]
> 
> 
> 
> Thanks for the info about UDP port, I was expecting it to rather look like 
> this: <URL:http://1.2.3.4:500>1.2.3.4:500 and not separated wit the dot 
> (.). 
> 
> 
> 
> Regards,
> Jakub 
> 
> 
> 
> 2012/8/29 Roel van Meer 
> <<URL:mailto:roel.vanmeer at bokxing.nl>roel.vanmeer at bokxing.nl>
> 
>    
>    Jakub Sobczak writes:
>    
>      tcpdump shows:
>      
>         10:37:<URL:tel:17.007960>17.007960 IP remote-ip.500 >  my-ip.500 : 
>      isakmp: phase 1 I ident
>         10:37:<URL:tel:17.008104>17.008104 IP my-ip.500 >  remote-ip.500 : 
>      isakmp: phase 1 R inf
>      
>      I do not know where this .500 comes from, it looks like this: 
>      <URL:tel:1.2.3.4.500>1.2.3.4.500, but anyway it seems fine. What 
>      worries me however is:
>    
>    .500 is the udp port that is used for setting up the connection.
>    
>    
>    
>         104 "conn" #1806: STATE_MAIN_I1: initiate
>         003 "conn" #1806: received Vendor ID payload [Dead Peer Detection]
>         003 "conn" #1806: ignoring unknown Vendor ID payload   
>       [699369228741c6d4ca094c93e242c9de19e7b7c60000000500000500]
>         003 "conn" #1806: Can't authenticate: no preshared key found for   
>       `my-ip' and `remote-ip'.  Attribute OAKLEY_AUTHENTICATION_METHOD
>    
>    Ok, you do receive traffic from the remote, so the firewall is not the 
>    problem. It can't find a secret for your configured connection, however.
>    Openswan does not pick up changes in your secrets file automatically.
>    Have you restarted openswan since you put the secret in ipsec.secrets? 
>    You can also run
>    ipsec auto --rereadsecrets
>    to make sure Openswan picks up any changes there.
>    
>    Regards,
>    
>    Roel
>    
>    
>    
>         003 "conn" #1806: no acceptable Oakley Transform
>         214 "conn" #1806: STATE_MAIN_I1: NO_PROPOSAL_CHOSEN
>      
>      Again, my ipsec.secrets looks like this (copy-paste): 
>         my-ip remote-ip : PSK "some-presharedkey"
>      
>      What is going on? Maybe I have to install something?
>    
>    
>    
>      
>      Regards,
>      Jakub 
>      
>      
>      
>      
>      2012/8/29 Roel van Meer 
>      <<URL:mailto:<URL:mailto:roel.vanmeer at bokxing.nl>roel.vanmeer at bokxing. 
>      nl><URL:mailto:roel.vanmeer at bokxing.nl>roel.vanmeer at bokxing.nl>
>      
>         Jakub Sobczak writes:
>              Yes, the shared key line is formatted in the following way:  
>          
>       1.2.3.4 <URL:<URL:<URL:http://5.6.7.8/>http://5.6.7.8/><URL:http://5. 
>      6.7.8/>http://5.6.7.8/><URL:<URL:http://5.6.7.8>http://5.6.7.8>     
>       <URL:http://5.6.7.8>5.6.7.8: PSK "sharedkey" .           I changed 
>      auto=add to auto=start hoping it would help, but it didn't:
>      
>                   ipsec auto --up conn
>              104 "conn" #1616: STATE_MAIN_I1: initiate
>              010 "conn" #1616: STATE_MAIN_I1: retransmission; will wait 
>      20s for         response
>              010 "conn" #1616: STATE_MAIN_I1: retransmission; will wait 
>      40s for         response
>              031 "conn" #1616: max number of retransmissions (2) reached   
>            STATE_MAIN_I1.  No response (or no acceptable response) to our 
>      first         IKE message
>            The other side is not responding. Your firewall might not be 
>      set up    correctly. Can you see anything in the logs that indicate 
>      the other    side is trying to make a connection? If not, you could 
>      try to see if    there is traffic coming in from the other side.
>            With a command like
>         tcpdump -nli eth0 host 1.2.3.4
>         (assuming eth0 is the network device of your internet connection, 
>      and    replacing 1.2.3.4 by the ip address of the remote endpoint) 
>      you can see    what is happening on the wire.
>         Can you try to start the connection while running the tcpdump 
>      command    and post its output?
>                    I'm not sure if that's 
>      correct: ike=aes256-sha1-modp1536, but if they      say: Key Exchange 
>      Encryption: AES256  Data integrity: SHA1 and DH      group 5, do you 
>      think this line is not correct      (ike=aes256-sha1-modp1536)? I 
>      cannot influence that, I have to      adjust...      I am using: 
>      Linux Openswan U2.6.23/K2.6.32-31-server (netkey) Maybe      the 
>      problem is that I am not using certificates but psk?
>            The config details say the you need to use a shared key, so I 
>      assume    the problem is not related to certificates.
>                    How do I check if I  can use klips (which I believe I 
>      should use      instead of netkey).       You are already using 
>      klips, since you have this in your config:
>         protostack=klips
>            Regards,
>            Roel
>                                   Kind regards,
>           Jakub
>                          2012/8/29 Roel van Meer     
>       <<URL:mailto:<URL:mailto:<URL:mailto:roel.vanmeer at bokxing.nl>roel.van 
>      meer at bokxing.nl>roel.vanmeer at bokxing.     
>       nl><URL:mailto:<URL:mailto:roel.vanmeer at bokxing.nl>roel.vanmeer at bokxi 
>      ng.nl><URL:mailto:roel.vanmeer at bokxing.nl>roel.vanmeer at bokxing.nl>
>      
>                           Jakub Sobczak writes:
>                   I have never setup a live openSwan VPN tunnel, so please 
>      be           understanding =)
>                I received the following config details to establish 
>      connection      to      the other
>                company's gateway:
>                     Key Exchange Encryption:        AES256  Data 
>      integrity: SHA1
>                IKE SA renegotiation:   8 hrs                   Aggresive 
>      mode:      No
>                Use DH group:   1536 (group 5)
>                Authentication: PSK
>                     IKE phase 2
>                Data Encryption:        AES256  Data integrity: SHA1
>                IPSec SA renegotiation: 1 hr    Aggresive mode: No
>                Perfect forward secrecy:        Yes
>                Use DH group (Perfect forward secrecy) :        1536 (group 
>      5)
>                          This is my config from ipsec.conf (below). Apart 
>      from      that, I also      have
>                ipsec.secret with the following content: left_IP(mine)
>                right_IP(othercompany) "PSK"
>                 Just to be sure, the format of this needs to be:
>              1.2.3.4     
>       <URL:<URL:<URL:http://5.6.7.8>http://5.6.7.8><URL:http://5.6.7.8>http 
>      ://5.6.7.8><URL:<URL:http://5.6.7.8>http://5.6.7.8><URL:http://5.6.7.8 
>      >5.6.7.8:      PSK "sharedkey"
>                         config setup
>                        nat_traversal=yes
>                                
>        virtual_private=%v4:<URL:<URL:<URL:http://10.0.0.0/8,%v4:192.168.0.0 
>      /16,%v>http://10.0.0.0/8,%v4:192.168.0.0/16,%v     
>       4:172><URL:http://10.0.0.0/8,%v4:192.168.0.0/16,%v4:172>http://10.0.0 
>      .0/8,%v4:192.168.0.0/16,%v4:172.         
>        16.0.0/12><URL:<URL:http://10.0.0.0/8,%v4:192.168.0.0/16,%v4:172.16. 
>      0.0/12>http://10.0.0.0/8,%v4:192.168.0.0/16,%v4:172.16.0.0/12     
>       ><URL:http://10.0.0.0/8,%v4:192.168.0.0/16,%v4:172.16.0.0/12>10.0.0.0 
>      /8,%v4:192.168.0.0/16,%v4:172.16.0.0/12
>      
>                             oe=off
>                        protostack=klips
>                conn abc
>                        #General
>                        keyingtries=1
>                        auto=add
>                 If you specify "auto=add" the other end will have to 
>      initiate      the    connection. Can you post the logs that show what 
>      happens      during this    time?
>                              #IKE Params
>                        authby=secret
>                        keyexchange=ike
>                 This parameter does not occur in my manpage. Which version 
>      of      openswan    are you using?
>                                 ikelifetime=8h
>                        ike=aes256-sha1-modp1536
>                        #IPSec Params
>                        type=tunnel
>                        auth=esp
>                        pfs=yes
>                        compress=no
>                        keylife=60m
>                        esp=aes256-sha1
>                        #pfsgroup=modp1536
>                        # Left security gateway, subnet behind it, nexthop 
>           toward      right.
>                        left=my_IP
>                            
>       leftsubnet=<URL:<URL:<URL:http://192.168.5.1/32>http://192.168.5.1/32 
>      ><URL:http://192.168.5.1/32>http://192.168.5.1/32><URL:     
>       <URL:http://192.168.5.1/32>http://192.168.5.1/32><URL:http://192.168. 
>      5.1/32>192.168.5.1/32                           right=other_comp_IP
>      
>                               rightsubnet=some_subnet
>                 As far as I can see, this is all correct.
>              A general remark: in my experience it is often easier to 
>      begin      with    less specific configuration, for example:
>              ike=aes
>              instead of
>              ike=aes256-sha1-modp1536
>                         The second phase does not seem to be established. 
>      What      is wrong? I      believe
>                something with pfsgroup? How to properly set DH group?
>                 Best regards,
>                 Roel
>           
> 


More information about the Users mailing list