diff --git a/configs/sip.conf.sample b/configs/sip.conf.sample
index 8ea15ec73a..9bc3a8d6b2 100644
--- a/configs/sip.conf.sample
+++ b/configs/sip.conf.sample
@@ -1018,6 +1018,7 @@ srvlookup=yes                   ; Enable DNS SRV lookups on outbound calls
 ;defaultip=192.168.0.60          ; IP address to use if peer has not registered
 ;deny=0.0.0.0/0.0.0.0            ; ACL: Control access to this account based on IP address
 ;permit=192.168.0.60/255.255.255.0
+;permit=192.168.0.60/24          ; we can also use CIDR notation for subnet masks
 
 ;[cisco1]
 ;type=friend