diff --git a/snmp/redis.pl b/snmp/redis.pl
index 8d7001b3d..812c98f8b 100755
--- a/snmp/redis.pl
+++ b/snmp/redis.pl
@@ -2,14 +2,24 @@
 
 =head1 NAME
 
-redis.pl - LinbreNMS JSON extend for redis.
+redis - LinbreNMS JSON extend for redis.
 
 =head1 SYNOPSIS
 
-logsize [B<-B>]
+redis [B<-B>] [B<-c> <config file>]
+
+redis [B<-v>|B<--version>]
+
+redis [B<-h>|B<--help>]
 
 =head1 SWITCHES
 
+=head2 -c
+
+Config file to use.
+
+Default: /usr/local/etc/redis_extend.json
+
 =head2 -B
 
 Do not the return output via GZip+Base64.
@@ -38,6 +48,36 @@ =head1 SETUP
     # if running it via cron
     extend redis /usr/local/etc/snmp/redis.pl
 
+If for multiple instances or the default of 'redis-cli info'
+won't work, a config file will be needed. The config format
+is JSON.
+
+The config entries are as below.
+
+      - command :: If single instance, the command to use.
+          Type :: String
+          Default :: redis-cli
+
+      - instances :: A hash where the keys are the instances names
+                and the values for each key are the command to use.
+
+The default config would be like below, which will be what is used
+if no config file is specified/found.
+
+    {
+        "command": "redis-cli info"
+    }
+
+For something with two instances, "foo" on port 6379 and "bar" on port 6380
+it would be like below.
+
+    {
+        "instances": {
+            "foo": "redis-cli -p 6379",
+            "bar": "redis-cli -p 6380"
+        }
+    }
+
 =cut
 
 use warnings;