gre: Check whether IPv6 is compiled into the kernel.

[sliver-openvswitch.git] / INSTALL.Linux

diff --git a/INSTALL.Linux b/INSTALL.Linux
index 20a0dd8..c3cf2f8 100644 (file)
--- a/INSTALL.Linux
+++ b/INSTALL.Linux
@@ -48,6 +48,10 @@ INSTALL.userspace for more information.
       and NET_ACT_POLICE, either built-in or as modules.
       (NET_CLS_POLICE is obsolete and not needed.)
 
+      If GRE tunneling is being used it is recommended that the kernel
+      be compiled with IPv6 support (CONFIG_IPV6).  This allows for
+      special handling (such as path MTU discovery) of IPv6 packets.
+
     - To build a kernel module, you need the same version of GCC that
       was used to build that kernel.