From db12675ec45c9c9bfe5b6ae000a38c76bdf6aad5 Mon Sep 17 00:00:00 2001
From: Tobias Brunner <tobias@strongswan.org>
Date: Thu, 23 Mar 2017 17:29:47 +0100
Subject: [PATCH] conf: Document recommended lower limit for SPIs

---
 conf/options/charon.opt | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/conf/options/charon.opt b/conf/options/charon.opt
index 493d73f16..4c4311e81 100644
--- a/conf/options/charon.opt
+++ b/conf/options/charon.opt
@@ -353,6 +353,10 @@ charon.signature_authentication_constraints = yes
 charon.spi_min = 0xc0000000
 	The lower limit for SPIs requested from the kernel for IPsec SAs.
 
+	The lower limit for SPIs requested from the kernel for IPsec SAs. Should not
+	be set lower than 0x00000100 (256), as SPIs between 1 and 255 are reserved
+	by IANA.
+
 charon.spi_max = 0xcfffffff
 	The upper limit for SPIs requested from the kernel for IPsec SAs.