add endpointipv6 for host

logic/peers.go

@@ -207,8 +207,21 @@ func GetPeerUpdateForHost(network string, host *models.Host, allNodes []models.N
 					uselocal = false
 				}
 			}
+
+			//if host is ipv4 only or ipv4+ipv6, set the peer endpoint to ipv4 address, if host is ipv6 only, set the peer endpoint to ipv6 address
+			peerEndpoint := peerHost.EndpointIP
+			if ipv4 := host.EndpointIP.To4(); ipv4 != nil {
+				peerEndpoint = peerHost.EndpointIP
+			} else {
+				//if peer host's ipv6 address is empty, it means that peer is an IPv4 only host
+				//IPv4 only host could not communicate with IPv6 only host
+				if peerHost.EndpointIPv6 != nil && peerHost.EndpointIPv6.String() != "" {
+					peerEndpoint = peerHost.EndpointIPv6
+				}
+			}
+
 			peerConfig.Endpoint = &net.UDPAddr{
-				IP:   peerHost.EndpointIP,
+				IP:   peerEndpoint,
 				Port: GetPeerListenPort(peerHost),
 			}
 

models/host.go

@@ -63,6 +63,7 @@ type Host struct {
 	Interfaces          []Iface          `json:"interfaces"              yaml:"interfaces"`
 	DefaultInterface    string           `json:"defaultinterface"        yaml:"defaultinterface"`
 	EndpointIP          net.IP           `json:"endpointip"              yaml:"endpointip"`
+	EndpointIPv6        net.IP           `json:"endpointipv6"            yaml:"endpointipv6"`
 	IsDocker            bool             `json:"isdocker"                yaml:"isdocker"`
 	IsK8S               bool             `json:"isk8s"                   yaml:"isk8s"`
 	IsStatic            bool             `json:"isstatic"                yaml:"isstatic"`