add step for net.ipv4.ip_forward parameter

README.md

@@ -43,6 +43,20 @@ create a `hosts` file before running any of the playbooks. Copy the
 cp hosts.sample hosts
 ```
 
+**Important**: You will need to edit the hosts file, particularly the
+value of `upstream_dns`. It should be one of the nameservers which the
+VM is using (check /etc/resolv.conf).
+
+**Also important**: You need to enable packet forwarding in the VM. Add
+or uncomment the following line in `/etc/sysctl.conf`:
+```
+net.ipv4.ip_forward=1
+```
+Then run:
+```
+sysctl -p
+```
+
 Make sure you have the `bridge-utils` package installed in the VM.
 This should be installed by default on Ubuntu, but you may have to manually
 install it on Debian.

outsider/README.md

@@ -69,16 +69,6 @@ Once you have created the container, edit the following line in
 lxc.net.0.link = lxcbr2
 ```
 
-You also need to enable packet forwarding in the VM. Add or enable the
-following line in `/etc/sysctl.conf`:
-```
-net.ipv4.ip_forward=1
-```
-Then run:
-```
-sysctl -p
-```
-
 As usual, chroot into the container and install python3.
 Then start it and run the playbook:
 ```