VYOS (1.1.8) ipsec site-to-site tunnel and l2tp vpn on the same vyos router

Hello All,

I am new to VYOS.

Trying to set up site to site tunnels between multiple locations (mesh) and also L2TP VPN server on all the vyos routers for the remote users to dial into the network.

Site-to-site works fine but not the VPN for the remote users.
If I take out the site to site config then VPN works. Users can dial-in. I am not able to make both site-to-site tunnels and l2tp/ipsec vpn work at the same time.

Any help is appreciated.

Following is my network diagram and the configuration (Site A )


interfaces {
    ethernet eth0 {
        address 1.2.3.4/24
        duplex auto
        smp_affinity auto
        speed auto
    }
    ethernet eth1 {
        address 10.10.1.1/24
        duplex auto
        smp_affinity auto
        speed auto
    }
    ethernet eth2 {
        duplex auto
        smp_affinity auto
        speed auto
    }
    ethernet eth3 {
        duplex auto
        smp_affinity auto
        speed auto
    }
    loopback lo {
    }
    vti vti0 {
        address 172.16.10.1/30
        description "VTI between Site A and Site B"
    }
    vti vti1 {
        address 172.16.20.1/30
        description "VTI between Site A and Site C"![network|690x493](upload://xe9qzznr70UPInep1tQiLWUhhz0.png) 
    }
}
nat {
    source {
        rule 100 {
            outbound-interface eth0
            translation {
                address masquerade
            }
        }
    }
}
protocols {
    static {
        interface-route 10.10.2.0/24 {
            next-hop-interface vti0 {
            }
        }
        interface-route 10.10.5.0/24 {
            next-hop-interface vti1 {
            }
        }
        interface-route 10.10.6.0/24 {
            next-hop-interface vti0 {
            }
        }
        interface-route 10.20.0.0/16 {
            next-hop-interface vti1 {
            }
        }
    }
}
service {
    dhcp-server {
        disabled false
        shared-network-name Site-A-pool {
            authoritative enable
            subnet 10.10.1.0/24 {
                default-router 10.10.1.1
                dns-server 10.10.1.1
                lease 86400
                start 10.10.1.100 {
                    stop 10.10.1.199
                }
            }
        }
    }
    dns {
        forwarding {
            cache-size 150
            listen-on eth1
            name-server 8.8.8.8
            name-server 8.8.4.4
        }
    }
    ssh {
        port 22
    }
}
system {
    config-management {
        commit-revisions 20
    }
    console {
        device ttyS0 {
            speed 9600
        }
    }
    gateway-address 1.2.3.1
    host-name vyos-site-a
    login {
        user vyos {
            authentication {
                encrypted-password XXXXXXXX
            }
            level admin
        }
    }
    ntp {
        server 0.pool.ntp.org {
        }
        server 1.pool.ntp.org {
        }
        server 2.pool.ntp.org {
        }
    }
    package {
        auto-sync 1
        repository community {
            components main
            distribution helium
            password ""
            url http://packages.vyos.net/vyos
            username ""
        }
    }
    syslog {
        global {
            facility all {
                level notice
            }
            facility protocols {
                level debug
            }
        }
    }
    time-zone UTC
}
vpn {
    ipsec {
        esp-group ESP-Default {
            compression disable
            lifetime 3600
            mode tunnel
            pfs dh-group16
            proposal 1 {
                encryption aes256
                hash sha256
            }
        }
        ike-group IKE-Default {
            dead-peer-detection {
                action clear
                interval 30
                timeout 90
            }
            ikev2-reauth no
            key-exchange ikev1
            lifetime 86400
            proposal 1 {
                dh-group 16
                encryption aes256
                hash sha256
            }
        }
        ipsec-interfaces {
            interface eth0
        }
        logging {
            log-modes all
        }
        nat-networks {
            allowed-network 0.0.0.0/0 {
            }
        }
        nat-traversal enable
        site-to-site {
            peer 1.2.3.5 {
                authentication {
                    id 1.2.3.4
                    mode pre-shared-secret
                    pre-shared-secret XXXXXX
                }
                connection-type initiate
                default-esp-group ESP-Default
                ike-group IKE-Default
                ikev2-reauth inherit
                local-address 1.2.3.4
                vti {
                    bind vti0
                    esp-group ESP-Default
                }
            }
            peer 1.2.3.6 {
                authentication {
                    id 1.2.3.4
                    mode pre-shared-secret
                    pre-shared-secret XXXXXXX
                }
                connection-type initiate
                default-esp-group ESP-Default
                ike-group IKE-Default
                ikev2-reauth inherit
                local-address 1.2.3.4
                vti {
                    bind vti1
                    esp-group ESP-Default
                }
            }
        }
    }
    l2tp {
        remote-access {
            authentication {
                local-users {
                    username test {
                        password xxxxx
                    }
                }
                mode local
            }
            client-ip-pool {
                start 10.10.4.1
                stop 10.10.4.255
            }
            dns-servers {
                server-1 8.8.8.8
                server-2 8.8.4.4
            }
            ipsec-settings {
                authentication {
                    mode pre-shared-secret
                    pre-shared-secret XXXXXXX
                }
                ike-lifetime 3600
            }
            outside-address 1.2.3.4
        }
    }
}


/* Warning: Do not remove the following line. */
/* === vyatta-config-version: "cluster@1:config-management@1:conntrack-sync@1:conntrack@1:cron@1:dhcp-relay@1:dhcp-server@4:firewall@5:ipsec@4:nat@4:qos@1:quagga@2:system@6:vrrp@1:wanloadbalance@3:webgui@1:webproxy@1:zone-policy@1" === */
/* Release version: VyOS 1.1.8 */

Thanks

Hello, @machanta!
You can check content of /etc/ipsec*, /etc/strongswan.conf and logs to find a reason for this.

We can help with this problem and perform tests, but only if you update version to 1.2.0 and issue will be confirmed with this version too.

Thanks. We will eventually move to 1.2.0.
We switched to GRE/IPSEC tunnels and everything works perfectly now. No issues what so ever. I am aware that GRE adds overhead and impacts the overall bandwidth but we are ok for now.

Thanks