Overview

Host to Site configurations are very similar to Host to Host configurations, especially the authentication methods are the same. Added changes to the configurations are the values for rightsourceip and rightsubnets. These values will expose the listed subnets to the IPSec tunnel and will allows clients in these subnets to communicate with the host (west) node and will allow the west node to allow to communicate with clients in the listed subnets.

In case rightsourceip is used the communication between the 2 nodes will not be encrypted only communication between the west node and the subnet would be encrypted. If a value is defined, then all communication between the East and the west host will use the defined IP Address.

Figure 12: Host to Site Configuration Example Details

Host to Site with Certificate

1. Prepare both nodes (see: How to Prepare a Nodegrid Node for IPSec)
   
2. Get the required Certificate File for both nodes (see: How to Create Certificates for IPSec).
   
1. Root CA certificate as .crt file
   
2. Certificate for both nodes in .crt format
   
3. Certificate and private key for both nodes in pkcs#12 format
   

Example:


• zpeca.crt
  
• ng-east.crt
  
• ng-west.crt
  
• ng-east.p12
  
• ng-west.p12
  
3. Import the Root Certificate
   
   Note: Example executed on the west node.
   

Format:


certutil -A -i  -n "" -t "CT,," -d sql:/etc/ipsec/ipsec.d/

Example:


root@ng-west:~# certutil -A -i zpeca.crt -n "zpeca" -t "CT,," -d sql:/etc/ipsec/ipsec.d/

4. Import Intermediate Certificate Authorities if that exist
   

Format:


certutil -A -i  -n "" -t ",," -d sql:/etc/ipsec/ipsec.d/

Example:


root@ng-west:~# certutil -A -i euzpeca.crt -n "euzpeca" -t "CT,," -d sql:/etc/ipsec/ipsec.d/

5. Import the private key and certificate specific to this node
   

Format:


certutil -A -i  -n "" -t "P,," -d sql:/etc/ipsec/ipsec.d/

Example:


root@ng-west:~#  ipsec import ng-west.p12 -n ng-west -d sql:/etc/ipsec/ipsec.d/
Enter password for PKCS12 file:
pk12util: PKCS12 IMPORT SUCCESSFUL

6. Import the remote node certificates
   

Format:


certutil -A -i  -n "" -t "P,," -d sql:/etc/ipsec/ipsec.d/

Example:


root@ng-west:~# certutil -A -i ng-east.crt -n "ng-east" -t "P,," -d sql:/etc/ipsec/ipsec.d/

7. Create connection configuration file in /etc/ipsec/ipsec.d/ directory as root user
   

Fields	Values	Comments
Connection name	<String>
leftid	%fromcert	The leftid will be populated from the certificate
left	<IP or FQDN> of the West/Left host	Additional to an actual IP address can the following values be used. These are resolved when the service starts. %defaultgateway %eth0
leftrsasigkey	%cert	Uses the RSA key of the Certificate
leftcert	<IDENTIFIER>	Certificate Identifier
rightid	%fromcert	The rightid will be populated from the certificate
right	<IP or FQDN> of the East/Right host	Additional to an actual IP address can the following values be used. These are resolved when the service starts. %defaultgateway %eth0
rightsourceip	<INTERNAL IP TO BE USED>	IP address if the east node which should be used for the tunnel communication. This IP should belong the rightsubnet.
rightsubnets	<LIST OF SUBNETS>	One or multiple subnet can be defined, for each subnet a individual tunnel will be created
rightrsasigkey	%cert	Uses the RSA key of the Certificate
rightcert	<IDENTIFIER>	Certificate Identifier
auto	start	The setting regulates when the IPSec tunnel will be established. Following values are accepted: add (manual start), start (starts with the service), ondemand (will be established if traffic exists), ignore (connection will be ignored and not used)
connaddrfamily	ipv4	Possiable values are ipv4 or ipv6

Format:


conn 
     connaddrfamily=ipv4
      auto=

      leftid=%fromcert
      left=FQDN>
      leftrsasigkey=%cert
      leftcert=
      
      rightid=%fromcert
      right=FQDN>
      rightsourceip=
      rightsubnet=MASK>
      rightrsasigkey=%cert
      rightcert=

Example /etc/ipsec/ipsec.d/host-to-site-cert.conf


conn host-to-site-cert
        connaddrfamily=ipv4
        auto=start

        leftid=%fromcert
        left=192.168.50.4
        leftrsasigkey=%cert
        leftcert=ng-west

        rightid=%fromcert
        right=192.168.58.4
        rightsourceip=192.168.60.4
        rightsubnet=192.168.60.0/24
        rightrsasigkey=%cert
        rightcert=ng-east

8. Copy the configuration file only to the other node. The Secret File does not need to be copied in this case
   
9. Restart IPSec service on both nodes
   

root@ng-west:~# ipsec restart
Redirecting to: /etc/init.d/ipsec stop
Shutting down pluto IKE daemon
002 shutting down

Redirecting to: /etc/init.d/ipsec start
Starting pluto IKE daemon for IPsec: .
root@ng-west:~#

10. Confirm that the tunnel was established
    
1. Short information
   

root@ng-west:/etc/ipsec/ipsec.d# ipsec whack --trafficstatus
006 #4: "host-to-site-cert", type=ESP, add_time=0, inBytes=252, outBytes=252, id='C=US, ST=California, L=Fremont, CN=ng-east'
006 #3: "host-to-site-cert", type=ESP, add_time=1524106315, inBytes=0, outBytes=0, id='C=US, ST=California, L=Fremont, CN=ng-east'

2. More Detailed Information
   

root@ng-west:~# ipsec whack --status |grep host-to-site-cert
……………. 
000 #4: "host-to-site-cert":500 STATE_QUICK_I2 (sent QI2, IPsec SA established); EVENT_SA_REPLACE in 27850s; newest IPSEC; eroute owner; isakmp#1; idle; import:admin initiate
000 #4: "host-to-site-cert" esp.8f05c62c@192.168.58.4 esp.33385f41@192.168.50.4 tun.0@192.168.58.4 tun.0@192.168.50.4 ref=0 refhim=0 Traffic: ESPin=252B ESPout=252B! ESPmax=4194303B
000 #1: "host-to-site-cert":500 STATE_MAIN_I4 (ISAKMP SA established); EVENT_SA_REPLACE in 2409s; newest ISAKMP; lastdpd=-1s(seq in:0 out:0); idle; import:admin initiate
000 #3: "host-to-site-cert":500 STATE_QUICK_R2 (IPsec SA established); EVENT_SA_REPLACE in 28316s; isakmp#2; idle; import:not set
000 #3: "host-to-site-cert" esp.759f48b6@192.168.58.4 esp.62dcc0e@192.168.50.4 tun.0@192.168.58.4 tun.0@192.168.50.4 ref=0 refhim=0 Traffic: ESPin=0B ESPout=0B! ESPmax=4194303B
000 #2: "host-to-site-cert":500 STATE_MAIN_R3 (sent MR3, ISAKMP SA established); EVENT_SA_REPLACE in 3116s; lastdpd=-1s(seq in:0 out:0); idle; import:not set