EBGP underlay_as enhancements (#362)

netsim/ansible/templates/bgp/srlinux.j2

@@ -9,5 +9,4 @@ updates:
     accept: {}
 
 {% from "srlinux.macro.j2" import bgp_config with context %}
-{% set _add_interfaces = bgp.update( { 'interfaces': interfaces } ) %}
 {{ bgp_config('default',bgp.as,bgp.router_id,bgp,{}) }}

netsim/ansible/templates/bgp/srlinux.macro.j2

@@ -124,7 +124,7 @@
 {# {{     bgp_network(af,loopback[af]) }} #}
 {%   endif %}
 
-{% for l in vrf_bgp.interfaces|default([]) if l.bgp.advertise|default("") and l[af] is defined and not 'vrf' in l %}
+{% for l in interfaces|default([]) if l.bgp.advertise|default("") and l[af] is defined and not 'vrf' in l %}
 {# {{     bgp_network(af,l[af]) }} #}
 {%   endfor %}
 {%   for pfx in bgp.originate|default([]) if af == 'ipv4' %}
@@ -155,25 +155,40 @@
 {% endif %}
 {% elif n[af]==True and af=='ipv6' %}
 {# BGP unnumbered for IPv6 LLA #}
+{% set peer_group = "ebgp-unnumbered" + (('-' + n.local_as|string()) if n.local_as is defined else '') %}
 
 - path: network-instance[name={{vrf}}]/ip-forwarding
   val:
    receive-ipv4-check: false
    _annotate_receive-ipv4-check: "Allow IPv4 on IPv6 unnumbered interfaces"
 
-{% set ns = namespace(l=false) %}
-{% for i in vrf_bgp.interfaces|default([]) if i.ifindex == n.ifindex %}
-{% set ns.l = i %}
-{% endfor %}
-{% if ns.l %}
-{% set if_name_index = ns.l.ifname.split('.') %}
+{% for i in interfaces|default([]) if i.ifindex == n.ifindex %}
+{% set if_name_index = i.ifname.split('.') %}
 {% set if_name = if_name_index[0] %}
 {% set if_index = if_name_index[1] if if_name_index|length > 1 else '0' %}
 - path: network-instance[name={{vrf}}]/protocols/bgp/dynamic-neighbors/interface[interface-name={{if_name}}.{{if_index}}]
   val:
-   peer-group: "ebgp-unnumbered"
+   peer-group: "{{ peer_group }}"
    allowed-peer-as: [ {{ n.as }}..{{ n.as }} ]
+
+{% if peer_group != "ebgp-unnumbered" %}
+- path: network-instance[name={{vrf}}]/protocols/bgp/group[group-name={{peer_group}}]
+  val:
+   admin-state: enable
+   import-policy: accept_all
+   export-policy: accept_all
+   timers:
+    connect-retry: 10
+    _annotate_connect-retry: "Reduce default 120s to 10s"
+    minimum-advertisement-interval: 1
+   local-as:
+   - as-number: {{ n.local_as }}
+     prepend-global-as: false
+   ipv4-unicast:
+     advertise-ipv6-next-hops: true
+     receive-ipv6-next-hops: true
 {% endif %}
+{% endfor %}
 {% endif %}
 {% endfor %}
 {% endfor %}

netsim/augment/links.py

@@ -335,10 +335,15 @@ def augment_lan_link(link: Box, addr_pools: Box, ndict: dict, defaults: Box) ->
     node_if['data'].neighbors = []
     for remote_if in interfaces:
       if remote_if['node'] != node_if['node'] or remote_if['data'].ifindex != node_if['data'].ifindex:
-        ngh_data = { 'ifname': remote_if['data'].ifname, 'node': remote_if['node'] }
+        ngh_data = Box({ 'ifname': remote_if['data'].ifname, 'node': remote_if['node'] })
         for af in ('ipv4','ipv6'):
           if af in remote_if['data']:
             ngh_data[af] = remote_if['data'][af]
+
+        # List enabled modules that have interface level attributes; copy those attributes too
+        mods_with_ifattr = Box({ m : True for m in ndict[remote_if['node']].get('module',[]) if defaults[m].attributes.get('interface',None) })
+        ifaddr_add_module(ngh_data,remote_if['data'],mods_with_ifattr)
+
         node_if['data'].neighbors.append(ngh_data)
 
   if common.DEBUG:     # pragma: no cover (debugging)
@@ -418,6 +423,10 @@ def augment_p2p_link(link: Box, addr_pools: Box, ndict: dict, defaults: Box) ->
       if af in interfaces[i]:
         link[end_names[i]][af] = interfaces[i][af]
 
+    # JvB: copy module specific link attributes like bgp.local_as
+    mods_with_ifattr = Box({ m : True for m in ndict[remote].get('module',[]) if defaults[m].attributes.get('interface',None) })
+    ifaddr_add_module(interfaces[i]['neighbors'][0],interfaces[1-i],mods_with_ifattr)
+
   return link
 
 def check_link_attributes(data: Box, nodes: dict, valid: set) -> bool:

netsim/extra/ebgp-local_as.py

@@ -49,13 +49,12 @@ def ebgp_neighbor(n: Box, asn: int, intf: Box, extra_data: dict) -> Box:
   different underlay AS
 """
 def build_ebgp_sessions(node: Box, topology: Box) -> None:
-
     #
     # eBGP sessions - iterate over all links, find adjacent nodes
     # in different AS numbers, and create eBGP neighbors; set 'local_as'
     ibgp_as = topology.bgp['as']
     for l in [ l for l in node.get("interfaces",[]) if l.type == 'p2p' ]:
-      node_as = l.bgp.underlay_as if "bgp" in l and "underlay_as" in l.bgp else node.bgp.underlay_as
+      node_as = l.bgp.underlay_as if "bgp" in l and "underlay_as" in l.bgp else node.bgp.get('underlay_as',None)
 
       for ngb_ifdata in l.get("neighbors",[]):
         ngb_name = ngb_ifdata.node
@@ -80,9 +79,15 @@ def build_ebgp_sessions(node: Box, topology: Box) -> None:
             extra_data.local_if = l.ifname
           if common.DEBUG:
             print(f'ebgp-local_as: adding neighbor for node {node.name} peer {neighbor.name} peer_as={peer_as}')
-          node.bgp.neighbors.append( ebgp_neighbor(neighbor,peer_as,ngb_ifdata,extra_data) )
+          ebgp_data = ebgp_neighbor(neighbor,peer_as,ngb_ifdata,extra_data)
+          if 'vrf' in l:        # VRF neighbor
+            if not node.vrfs[l.vrf].bgp.neighbors:
+              node.vrfs[l.vrf].bgp.neighbors = []
+            node.vrfs[l.vrf].bgp.neighbors.append(ebgp_data)
+          else: 
+            node.bgp.neighbors.append(ebgp_data)
 
 def post_transform(topology: Box) -> None:
   for node in topology.nodes.values():
-    if "bgp" in node and "underlay_as" in node.bgp:
+    if "bgp" in node: # and "underlay_as" in node.bgp: Can also be at link level
         build_ebgp_sessions(node,topology)

tests/integration/vlan/vlan-vrf-route-leaking.yaml

@@ -0,0 +1,82 @@
+#
+# VRF lite implementation with VLAN trunks, including ebgp peering between vrfs locally
+#
+# * h1 and h2 should be able to ping each other, as well as h3 and h4
+# * h3 and h4 should be able to ping each other, as well as h1 and h2
+# 
+# A device has to support the following features to pass this test case:
+#
+# * Routed VLAN interfaces
+# * VRFs
+# * OSPF in VRFs
+# * BGP unnumbered using ipv6 lla
+#
+# Please note it might take a while for the lab to work due to
+# STP and OSPF setup phase
+#
+groups:
+  routers:
+    members: [ r1,r2,r3 ]
+    module: [ vlan,vrf,ospf ]
+  hosts:
+    device: linux
+    members: [ h1,h2,h3,h4 ]
+
+plugin: [ ebgp-local_as ]
+
+vrfs:
+  red:
+  blue:
+
+vlans:
+  red:
+    mode: route
+    vrf: red
+  blue:
+    mode: route
+    vrf: blue
+
+nodes:
+  r1:
+  r2:
+    module: [ vlan,vrf,ospf,bgp ]
+    bgp.as: 65000
+  r3:
+  h1:
+  h2:
+  h3:
+  h4:
+
+links:
+- r1:
+  r2:
+  vlan.trunk: [ red, blue ]
+- r2:
+  r3:
+  vlan.trunk: [ red, blue ]
+- interfaces: # VRF route leaking between red and blue on r2, using eBGP peering
+  - node: r2
+    vrf: red
+    ipv6: True
+    ipv4: False
+    bgp.underlay_as: 65001
+    # vlan.access: vrf-leak
+  - node: r2
+    vrf: blue
+    ipv6: True
+    ipv4: False
+    bgp.underlay_as: 65002
+    # vlan.access: vrf-leak
+  role: external
+- h1:
+  r1:
+    vlan.access: red
+- h3:
+  r1:
+    vlan.access: blue
+- h2:
+  r3:
+    vlan.access: red
+- h4:
+  r3:
+    vlan.access: blue

tests/topology/expected/bgp-community.yml

@@ -235,7 +235,9 @@ nodes:
       linkindex: 2
       name: r3 -> r2
       neighbors:
-      - ifname: GigabitEthernet0/1
+      - bgp:
+          local_as: 65002
+        ifname: GigabitEthernet0/1
         ipv4: 10.1.0.5/30
         node: r2
       ospf:

tests/topology/expected/vlan-vrf-lite.yml

@@ -215,6 +215,7 @@ nodes:
       - ifname: Ethernet2
         ipv4: 172.16.2.1/24
         node: r1
+        vrf: red
       role: stub
       type: lan
     mgmt:
@@ -242,6 +243,7 @@ nodes:
       - ifname: Ethernet3
         ipv4: 172.16.4.2/24
         node: r2
+        vrf: red
       role: stub
       type: lan
     mgmt:
@@ -269,6 +271,7 @@ nodes:
       - ifname: Ethernet3
         ipv4: 172.16.3.1/24
         node: r1
+        vrf: blue
       role: stub
       type: lan
     mgmt:
@@ -296,6 +299,7 @@ nodes:
       - ifname: Ethernet4
         ipv4: 172.16.5.2/24
         node: r2
+        vrf: blue
       role: stub
       type: lan
     mgmt:
@@ -320,6 +324,7 @@ nodes:
       - ifname: Ethernet4
         ipv4: 10.1.0.2/30
         node: r1
+        vrf: red
       type: p2p
     loopback:
       ipv4: 10.0.0.8/32

tests/topology/expected/vrf-igp.yml

@@ -385,6 +385,7 @@ nodes:
       - ifname: Ethernet2
         ipv4: 10.1.0.5/30
         node: pe1
+        vrf: red
       role: external
       type: p2p
     loopback:
@@ -420,6 +421,7 @@ nodes:
       - ifname: Ethernet2
         ipv4: 10.1.0.9/30
         node: pe2
+        vrf: blue
       ospf:
         area: 0.0.0.0
         network_type: point-to-point

tests/topology/expected/vrf.yml

@@ -279,6 +279,7 @@ nodes:
       - ifname: Ethernet1
         ipv4: 10.1.0.1/30
         node: r1
+        vrf: red
       role: external
       type: p2p
     - bgp:
@@ -365,6 +366,7 @@ nodes:
       - ifname: Ethernet2
         ipv4: 10.1.0.5/30
         node: r1
+        vrf: blue
       ospf:
         area: 0.0.0.0
         network_type: point-to-point