Fix VLAN lookup for node-local VLANs defined on a neighbor node (#645)

Co-authored-by: Jeroen van Bemmel <[email protected]>

netsim/modules/vlan.py

@@ -566,10 +566,16 @@ def create_loopback_vlan_links(topology: Box) -> None:
         topology.links.append(link_data)
 
 """
-get_vlan_data: Get VLAN data structure (node or topology)
+get_vlan_data: Get VLAN data structure (node or topology or interface neighbors)
 """
-def get_vlan_data(vlan: str, node: Box, topology: Box) -> typing.Optional[Box]:
-  return get_from_box(topology,f'vlans.{vlan}') or get_from_box(node,f'vlans.{vlan}')
+def get_vlan_data(vlan: str, node: Box, topology: Box, intf: Box) -> typing.Optional[Box]:
+  vlan_data = get_from_box(topology,f'vlans.{vlan}') or get_from_box(node,f'vlans.{vlan}')
+  if not vlan_data:
+    for n in intf.neighbors:  # Look for local vlan in neighbor
+      vlan_data = get_from_box(topology.nodes[n.node],f'vlans.{vlan}')
+      if vlan_data:
+        break
+  return vlan_data
 
 """
 get_vlan_mode: Get VLAN mode attribute (node or topology), default 'irb'
@@ -581,7 +587,7 @@ def get_vlan_mode(node: Box, topology: Box) -> str:
 update_vlan_neighbor_list: Build a VLAN-wide list of neighbors
 """
 def update_vlan_neighbor_list(vlan: str, phy_if: Box, svi_if: Box, node: Box,topology: Box) -> None:
-  vlan_data = get_vlan_data(vlan,node,topology)                         # Try to get global or node-level VLAN data
+  vlan_data = get_vlan_data(vlan,node,topology,phy_if)                  # Try to get global or node-level VLAN data
   if vlan_data is None:                                                 # ... and get out if there's none
     return
 
@@ -740,13 +746,13 @@ def create_svi_interfaces(node: Box, topology: Box) -> dict:
 def set_svi_neighbor_list(node: Box, topology: Box) -> None:
   for ifdata in node.interfaces:
     if 'vlan_name' in ifdata:
-      vlan_data = get_vlan_data(ifdata.vlan_name,node,topology)             # Try to get global or local VLAN data
-      if vlan_data is None:                                                 # Not found?
-        continue                                                            # ... too bad
-
       if get_from_box(ifdata,'vlan.routed_link'):                           # Don't update neighbors on a routed VLAN link
         continue
 
+      vlan_data = get_vlan_data(ifdata.vlan_name,node,topology,ifdata)      # Try to get global or local VLAN data
+      if vlan_data is None:                                                 # Not found?
+        continue                                                            # ... too bad
+
       if not 'host_count' in vlan_data:                                     # Calculate the number of hosts attached to the VLAN
         vlan_data.host_count = len([ n for n in vlan_data.neighbors if topology.nodes[n.node].get('role','') == 'host' ])
 

tests/topology/expected/vlan-access-neighbors.yml

@@ -71,7 +71,15 @@ nodes:
         ibgp:
         - standard
         - extended
-      neighbors: []
+      ipv4: true
+      neighbors:
+      - activate:
+          ipv4: true
+        as: 65001
+        ifindex: 1
+        ipv4: 172.16.0.3
+        name: r2
+        type: ebgp
       next_hop_self: true
       router_id: 10.0.0.1
     box: ceos:4.26.4M
@@ -90,11 +98,14 @@ nodes:
       ifname: Ethernet1
       ipv4: 172.16.0.1/24
       linkindex: 1
-      name: r1 -> s1
+      name: r1 -> [s1,r2]
       neighbors:
-      - ifname: Ethernet1
+      - ifname: Vlan1000
         ipv4: 172.16.0.2/24
         node: s1
+      - ifname: Ethernet1
+        ipv4: 172.16.0.3/24
+        node: r2
       type: lan
     loopback:
       ipv4: 10.0.0.1/32
@@ -117,7 +128,15 @@ nodes:
         ibgp:
         - standard
         - extended
-      neighbors: []
+      ipv4: true
+      neighbors:
+      - activate:
+          ipv4: true
+        as: 65000
+        ifindex: 1
+        ipv4: 172.16.0.1
+        name: r1
+        type: ebgp
       next_hop_self: true
       router_id: 10.0.0.3
     box: ceos:4.26.4M
@@ -136,9 +155,12 @@ nodes:
       ifname: Ethernet1
       ipv4: 172.16.0.3/24
       linkindex: 2
-      name: r2 -> s1
+      name: r2 -> [r1,s1]
       neighbors:
-      - ifname: Ethernet2
+      - ifname: Ethernet1
+        ipv4: 172.16.0.1/24
+        node: r1
+      - ifname: Vlan1000
         ipv4: 172.16.0.2/24
         node: s1
       type: lan

tests/topology/expected/vlan-access-node.yml

@@ -78,11 +78,12 @@ nodes:
       ifname: eth1
       ipv4: 172.16.0.1/24
       linkindex: 1
-      name: h1 -> s1
+      name: h1 -> [s1]
       neighbors:
-      - ifname: GigabitEthernet0/1
+      - ifname: BVI1
         ipv4: 172.16.0.2/24
         node: s1
+      role: stub
       type: lan
     mgmt:
       ifname: eth0
@@ -104,9 +105,12 @@ nodes:
       ifname: eth1
       ipv4: 172.16.1.4/24
       linkindex: 3
-      name: h2 -> s2
+      name: h2 -> [s1,s2]
       neighbors:
       - ifname: GigabitEthernet0/2
+        ipv4: 172.16.1.2/24
+        node: s1
+      - ifname: BVI1
         ipv4: 172.16.1.3/24
         node: s2
       type: lan
@@ -136,11 +140,14 @@ nodes:
       ifname: GigabitEthernet0/2
       ipv4: 172.16.1.2/24
       linkindex: 2
-      name: s1 -> s2
+      name: s1 -> [s2,h2]
       neighbors:
-      - ifname: GigabitEthernet0/1
+      - ifname: BVI1
         ipv4: 172.16.1.3/24
         node: s2
+      - ifname: eth1
+        ipv4: 172.16.1.4/24
+        node: h2
       type: lan
     - bridge_group: 1
       ifindex: 3

tests/topology/expected/vlan-coverage.yml

@@ -162,10 +162,11 @@ nodes:
       ifname: eth2
       ipv4: 172.16.1.4/24
       linkindex: 4
-      name: h2 -> s2
+      name: h2 -> [s2]
       neighbors:
-      - ifname: GigabitEthernet0/3
+      - ifname: BVI2
         node: s2
+      role: stub
       type: lan
     mgmt:
       ifname: eth0