[quagga]: Disable ipv4 over ipv6 and enable ipv6 over ipv4 peer group (#922)

* [bgpd]:disable ipv4 over ipv6 and enable ipv6 over ipv4 peer group

* update as comments

Author: sihuihan88

dockers/docker-fpm-quagga/bgpd.conf.j2

@@ -26,6 +26,7 @@ route-map TO_BGP_SPEAKER_V4 deny 10
 router bgp {{ DEVICE_METADATA['localhost']['bgp_asn'] }}
   bgp log-neighbor-changes
   bgp bestpath as-path multipath-relax
+  no bgp default ipv4-unicast
 {# Advertise graceful restart capability for ToR #}
 {% if minigraph_devices[inventory_hostname]['type'] == 'ToRRouter' %}
   bgp graceful-restart
@@ -64,9 +65,13 @@ router bgp {{ DEVICE_METADATA['localhost']['bgp_asn'] }}
   neighbor {{ neighbor_addr }} shutdown
 {% endif %}
 {% if neighbor_addr | ipv4 %}
+  address-family ipv4
 {% if minigraph_devices[inventory_hostname]['type'] == 'ToRRouter' %}
-  neighbor {{ neighbor_addr }} allowas-in 1
+    neighbor {{ neighbor_addr }} allowas-in 1
 {% endif %}
+    neighbor {{ neighbor_addr }} activate
+    maximum-paths 64
+  exit-address-family
 {% endif %}
 {% if neighbor_addr | ipv6 %}
   address-family ipv6
@@ -93,6 +98,14 @@ router bgp {{ DEVICE_METADATA['localhost']['bgp_asn'] }}
 {% for ip_range in bgp_peer['ip_range'] %}
   bgp listen range {{ip_range}} peer-group {{ bgp_peer['name'] }}
 {% endfor %}
+  address-family ipv4
+    neighbor {{ bgp_peer['name'] }} activate
+    maximum-paths 64
+  exit-address-family
+  address-family ipv6
+    neighbor {{ bgp_peer['name'] }} activate
+    maximum-paths 64
+  exit-address-family
 {% endfor %}
 {% endblock bgp_peers_with_range %}
 !