.

tmcast.py

@@ -75,6 +75,8 @@ def main():
         G = G4
     if "6" in action:
         G = G6
+    if G is None:
+        raise RuntimeError("4/6 must be specified")
 
     wg = sync.WorkGroup(context.background())
     if "tx" in action:

topo-B-A-C.sh

@@ -5,8 +5,8 @@
 #    netns:B          netns:A         netns:C
 #
 #       B  --- br0 ---  A  --- br1 ---  C
-#        b1           a1 a2           c1
-#        B1           A1 A2           C1
+#        b1  B1   A1  a1 a2  A2   C1  c1
+#
 #
 # should be run under unshare -mrun .
 # use nsenter --net={A,B,C} to enter into network namespace of A/B/C.
@@ -36,17 +36,38 @@ ip link set A1 master br0
 ip link set br0 up
 
 # A-br1-C
+nsenter --net=A -- ip link add a2 type veth peer A2
+nsenter --net=A -- ip link set A2 netns $PID
+nsenter --net=A -- ip link set a2 up
+ip link set A2 up
+
+unshare --net=C -- ip link set lo up
+nsenter --net=C -- ip link add c1 type veth peer C1
+nsenter --net=C -- ip link set C1 netns $PID
+nsenter --net=C -- ip link set c1 up
+ip link set C1 up
+
+ip link add br1 type bridge # vlan_filtering 1 mcast_snooping 0
+ip link set C1 master br1
+ip link set A2 master br1
+ip link set br1 up
 
 
+# addresses
 nsenter --net=B -- ip addr add 10.0.0.1/24 dev b1
 nsenter --net=A -- ip addr add 10.0.0.2/24 dev a1
+nsenter --net=C -- ip addr add 20.0.0.1/24 dev c1
+nsenter --net=A -- ip addr add 20.0.0.2/24 dev a2
 
+# multicast routing
 nsenter --net=B -- ip route add 224.0.0.0/4 dev b1
+nsenter --net=C -- ip route add 224.0.0.0/4 dev c1
 
-nsenter --net=A -- ip route add 224.0.0.0/4 dev a1
-# XXX append route to a2
+nsenter --net=A -- ip route add    224.0.0.0/4 dev a1   # NOTE on A 224.0.0.0/4 is routed
+nsenter --net=A -- ip route append 224.0.0.0/4 dev a2   # to _both_ a1 and a2
 
 
 # open terminals in A B C for play
 nsenter --net=B -- xfce4-terminal --title=B &
+nsenter --net=C -- xfce4-terminal --title=C &
 nsenter --net=A -- xfce4-terminal --title=A &