diff --git a/P4D2_2017_Fall/exercises/ecn/topology.json b/P4D2_2017_Fall/exercises/ecn/topology.json
new file mode 100644
index 0000000..2640a2b
--- /dev/null
+++ b/P4D2_2017_Fall/exercises/ecn/topology.json
@@ -0,0 +1,18 @@
+{
+    "hosts": [
+        "h1",
+        "h2",
+        "h3",
+        "h11",
+        "h22"
+    ],
+    "switches": {
+        "s1": { "cli_input" : "s1-commands.txt" },
+        "s2": { "cli_input" : "s2-commands.txt" },
+        "s3": { "cli_input" : "s3-commands.txt" }
+    },
+    "links": [
+              ["h1", "s1"], ["h11", "s1"], ["s1", "s2", "0", 0.5], ["s1", "s3"],
+              ["s3", "s2"], ["s2", "h2"], ["s2", "h22"], ["s3", "h3"]
+    ]
+}
diff --git a/P4D2_2017_Fall/vm/user-bootstrap.sh b/P4D2_2017_Fall/vm/user-bootstrap.sh
index d3d38ac..d00b3c9 100644
--- a/P4D2_2017_Fall/vm/user-bootstrap.sh
+++ b/P4D2_2017_Fall/vm/user-bootstrap.sh
@@ -126,10 +126,12 @@ cd .vim
 mkdir ftdetect
 mkdir syntax
 echo "au BufRead,BufNewFile *.p4      set filetype=p4" >> ftdetect/p4.vim
+echo "set bg=dark" >> /home/p4/.vimrc
 cp /home/vagrant/p4.vim syntax/p4.vim
 cd /home/vagrant
 sudo mv .vim /home/p4/.vim
 sudo chown -R p4:p4 /home/p4/.vim
+sudo chown p4:p4 /home/p4/.vimrc
 
 # Adding Desktop icons
 DESKTOP=/home/${USER}/Desktop
@@ -166,4 +168,4 @@ Name[en_US]=Sublime Text
 Icon=sublime-text
 Exec=/opt/sublime_text/sublime_text
 Comment[en_US]=
-EOF
\ No newline at end of file
+EOF