diff --git a/P4D2_2017_Fall/exercises/basic_tunnel/s1-commands.txt b/P4D2_2017_Fall/exercises/basic_tunnel/s1-commands.txt
index 8b7ba2d..179d7a5 100644
--- a/P4D2_2017_Fall/exercises/basic_tunnel/s1-commands.txt
+++ b/P4D2_2017_Fall/exercises/basic_tunnel/s1-commands.txt
@@ -1,7 +1,7 @@
 table_set_default ipv4_lpm drop
 table_add ipv4_lpm ipv4_forward 10.0.1.1/32 => 00:00:00:00:01:01 1
-table_add ipv4_lpm ipv4_forward 10.0.2.2/32 => 00:00:00:02:02:00 2
-table_add ipv4_lpm ipv4_forward 10.0.3.3/32 => 00:00:00:03:03:00 3
+table_add ipv4_lpm ipv4_forward 10.0.2.2/32 => 00:00:00:02:01:00 2
+table_add ipv4_lpm ipv4_forward 10.0.3.3/32 => 00:00:00:03:01:00 3
 
 table_set_default myTunnel_exact drop
 table_add myTunnel_exact myTunnel_forward 1 => 1
diff --git a/P4D2_2017_Fall/exercises/basic_tunnel/s2-commands.txt b/P4D2_2017_Fall/exercises/basic_tunnel/s2-commands.txt
index 39c553b..fb5a2bc 100644
--- a/P4D2_2017_Fall/exercises/basic_tunnel/s2-commands.txt
+++ b/P4D2_2017_Fall/exercises/basic_tunnel/s2-commands.txt
@@ -1,7 +1,7 @@
 table_set_default ipv4_lpm drop
 table_add ipv4_lpm ipv4_forward 10.0.1.1/32 => 00:00:00:01:02:00 2
 table_add ipv4_lpm ipv4_forward 10.0.2.2/32 => 00:00:00:00:02:02 1
-table_add ipv4_lpm ipv4_forward 10.0.3.3/32 => 00:00:00:03:03:00 3
+table_add ipv4_lpm ipv4_forward 10.0.3.3/32 => 00:00:00:03:02:00 3
 
 table_set_default myTunnel_exact drop
 table_add myTunnel_exact myTunnel_forward 1 => 2
diff --git a/P4D2_2017_Fall/exercises/basic_tunnel/send.py b/P4D2_2017_Fall/exercises/basic_tunnel/send.py
index 8621ac1..5279cba 100755
--- a/P4D2_2017_Fall/exercises/basic_tunnel/send.py
+++ b/P4D2_2017_Fall/exercises/basic_tunnel/send.py
@@ -25,7 +25,7 @@ def get_if():
 def main():
 
     if len(sys.argv)<4:
-        print 'pass 2 arguments: <ip_addr> <dst_nid> "<message>"'
+        print 'pass 3 arguments: <ip_addr> <dst_nid> "<message>"'
         exit(1)
 
     addr = socket.gethostbyname(sys.argv[1])
diff --git a/P4D2_2017_Fall/exercises/basic_tunnel/solution/basic_tunnel.p4 b/P4D2_2017_Fall/exercises/basic_tunnel/solution/basic_tunnel.p4
index a7339da..9d371c3 100644
--- a/P4D2_2017_Fall/exercises/basic_tunnel/solution/basic_tunnel.p4
+++ b/P4D2_2017_Fall/exercises/basic_tunnel/solution/basic_tunnel.p4
@@ -90,7 +90,7 @@ parser MyParser(packet_in packet,
 ************   C H E C K S U M    V E R I F I C A T I O N   *************
 *************************************************************************/
 
-control MyVerifyChecksum(in headers hdr, inout metadata meta) {   
+control MyVerifyChecksum(inout headers hdr, inout metadata meta) {   
     apply {  }
 }
 
diff --git a/P4D2_2017_Fall/exercises/calc/README.md b/P4D2_2017_Fall/exercises/calc/README.md
index c1b826d..4b6d92b 100644
--- a/P4D2_2017_Fall/exercises/calc/README.md
+++ b/P4D2_2017_Fall/exercises/calc/README.md
@@ -26,7 +26,7 @@ switch in Mininet to test its behavior.
   
    * start a Mininet instance with one switches (`s1`) connected to
      two hosts (`h1`, `h2`).
-   * The hosts are assigned IPs of `10.0.1.1` and `10.0.2.2`.
+   * The hosts are assigned IPs of `10.0.1.1` and `10.0.1.2`.
 
 2. We've written a small Python-based driver program that will allow
 you to test your calculator. You can run the driver program directly