diff --git a/docs/tunneling/index.md b/docs/tunneling/index.md
index 9150e6f..2b48962 100644
--- a/docs/tunneling/index.md
+++ b/docs/tunneling/index.md
@@ -3,3 +3,4 @@
 
 - [fastd](fastd)
 - [WireGuard](wireguard)
+- [IP tunnel](iptunnel)
diff --git a/docs/tunneling/gre.md b/docs/tunneling/iptunnel.md
similarity index 76%
rename from docs/tunneling/gre.md
rename to docs/tunneling/iptunnel.md
index fc0e7bc..90539c3 100644
--- a/docs/tunneling/gre.md
+++ b/docs/tunneling/iptunnel.md
@@ -1,11 +1,13 @@
 
-# Generic Routing Encapsulation (GRE)
+# IP tunnel
 
-*Note:* GRE tunnels are unencrypted.
+*Note:* IP tunnels (includes GRE, GRETAP and SIT) are unencrypted.
+
+## Generic Routing Encapsulation (GRE)
 
 GRE tunnels on layer 3 of the ISO/OSI model.
 
-## Configuring with ip
+### Configuring with ip
 
 To create a tunnel, you can use the following command:
 ```
@@ -32,7 +34,7 @@ ip addr add dev <interface> <ll>
 ```
 Replace `<ll>` with your own link-local address.
 
-### Automatic start with ifupdown
+#### Automatic start with ifupdown
 
 If you want to start the GRE tunnel automatically, you can use an ifupdown template which is placed under `/etc/network/interfaces.d`:
 ```
@@ -54,3 +56,7 @@ ifdown <interface>
 ## GRETAP
 
 GRETAP tunnels operate on layer 2 of the ISO/OSI model. To use a GRETAP tunnel, you only have to change the mode: For IPv4 `gretap` and for IPv6 `ip6gretap`.
+
+## Simple Internet Transition (SIT)
+
+SIT tunnels can be created in the same way as GRE tunnels. The difference is that you write `type sit` instead of `type gre`. SIT tunnels are designed to encapsulate IPv6 packets, so a SIT tunnel must be established over IPv4.