This is mostly stuff that I have found from several articles, mostly from here.

ERL: eth0 is WAN, eth1 (10.60.111.0/24) and eth2 (unused, not VPN’ed) are LAN FritzBoz: 192.168.1.0/24

This is the FritzBox config (go to VPN and them Import a config) fritzvpn.cfg:

vpncfg {
        connections {
                enabled = yes;
                conn_type = conntype_lan;
                name = "VPN Yeri";
                always_renew = yes;
                reject_not_encrypted = no;
                dont_filter_netbios = yes;
                localip = 0.0.0.0;
                local_virtualip = 0.0.0.0;
                remoteip = 0.0.0.0;
                remote_virtualip = 0.0.0.0;
                remotehostname = "erl.yeri.be";
                localid {
                        fqdn = "fritz.yeri.be";
                }
                remoteid {
                        fqdn = "erl.yeri.be";
                }
                mode = phase1_mode_idp;
                phase1ss = "all/all/all";
                keytype = connkeytype_pre_shared;
                key = "SOMEPASSWORD";
                cert_do_server_auth = no;
                use_nat_t = yes;
                use_xauth = no;
                use_cfgmode = no;
                phase2localid {
                        ipnet {
                                ipaddr = 192.168.1.0;
                                mask = 255.255.255.0;
                        }
                }
                phase2remoteid {
                        ipnet {
                                ipaddr = 10.60.111.0;
                                mask = 255.255.255.0;
                        }
                }
                phase2ss = "esp-all-all/ah-none/comp-all/pfs";
                accesslist = "permit ip any 10.60.111.0 255.255.255.0";
        }
        ike_forward_rules = "udp 0.0.0.0:500 0.0.0.0:500", 
                            "udp 0.0.0.0:4500 0.0.0.0:4500";
}

Be sure to modify the password, local (Fritz) and remote (ERL) LAN and edit the local and remote fqdn.

This is the ERL config (via ssh, you’ll need to set this:

yeri@sg-erl# show vpn ipsec 
 auto-update 60
 auto-firewall-nat-exclude enable
 esp-group FOO0 {
     proposal 1 {
         encryption aes256
         hash sha1
     }
 }
 ike-group FOO0 {
     dead-peer-detection {
         action restart
         interval 60
         timeout 60
     }
     lifetime 3600
     proposal 1 {
         dh-group 2
         encryption aes256
         hash sha1
     }
 }
 ipsec-interfaces {
     interface eth0
 }
 nat-networks {
     allowed-network 0.0.0.0/0 {
     }
 }
 nat-traversal enable
 site-to-site {
     peer fritz.yeri.be {
         authentication {
             mode pre-shared-secret
             pre-shared-secret SOMEPASSWORD
         }
         connection-type initiate
         description "VPN to fritz.yeri.be"
         ike-group FOO0
         local-address erl.yeri.be
         tunnel 1 {
             esp-group FOO0
             local {
                 prefix 10.60.111.0/24
             }
             remote {
                 prefix 192.168.1.0/24
             }
         }
     }
 }

Status:

yeri@sg:~$ show vpn ipsec status
IPSec Process Running PID: 20140

1 Active IPsec Tunnels

IPsec Interfaces :
        eth0    (no IP on interface statically configured as local-address for any VPN peer)
yeri@sg:~$ show vpn ipsec sa
peer-be.yeri.be-tunnel-1: #9, ESTABLISHED, IKEv1, 85a2d010ada73113:ca439c40ac3bca06
  local  'erl.yeri.be' @ 116.87.x.y
  remote 'fritz.yeri.be' @ 109.236.x.y
  AES_CBC-256/HMAC_SHA1_96/PRF_HMAC_SHA1/MODP_1024
  established 1592s ago, reauth in 1333s
  peer-fritz.yeri.be-tunnel-1: #1, INSTALLED, TUNNEL, ESP:AES_CBC-256/HMAC_SHA1_96/MODP_1024
    installed 1592 ago, rekeying in 1200s, expires in 2009s
    in  c0bb652e, 1038032 bytes, 10726 packets,     0s ago
    out 8d5df3f5, 532685 bytes,  6062 packets,     0s ago
    local  10.60.111.0/24
    remote 192.168.1.0/24

I haven’t really figured out what no IP on interface statically configured as local-address for any VPN peer means yet though.

Next up: VLANs