diff --git a/src/mpi/examples/nms-p2p-nix-distributed.cc b/src/mpi/examples/nms-p2p-nix-distributed.cc
index 99f85236a..24063fe9d 100644
--- a/src/mpi/examples/nms-p2p-nix-distributed.cc
+++ b/src/mpi/examples/nms-p2p-nix-distributed.cc
@@ -283,7 +283,7 @@ main (int argc, char *argv[])
         {
           oss.str ("");
           oss << 10 + z << ".5." << 10 + i << ".0";
-          address.SetBase (oss.str ().c_str (), "255.255.255.255");
+          address.SetBase (oss.str ().c_str (), "255.255.255.0");
           for (uint32_t j = 0; j < nLANClients; ++j)
             {
               Ptr<Node> node = CreateObject<Node> (z % systemCount);
diff --git a/src/nix-vector-routing/examples/nms-p2p-nix.cc b/src/nix-vector-routing/examples/nms-p2p-nix.cc
index 247b6ee45..f4ca2f627 100644
--- a/src/nix-vector-routing/examples/nms-p2p-nix.cc
+++ b/src/nix-vector-routing/examples/nms-p2p-nix.cc
@@ -367,7 +367,7 @@ main (int argc, char *argv[])
           if (!useIpv6)
             {
               oss << 10 + z << ".5." << 10 + i << ".0";
-              addressHelperv4.SetBase (oss.str ().c_str (), "255.255.255.255");
+              addressHelperv4.SetBase (oss.str ().c_str (), "255.255.255.0");
             }
           else
             {