diff --git a/src/GenericParser/IPAddress.purs b/src/GenericParser/IPAddress.purs
index ab26e3e..efa67fe 100644
--- a/src/GenericParser/IPAddress.purs
+++ b/src/GenericParser/IPAddress.purs
@@ -1,7 +1,7 @@
 -- | `IPAddress` is a parser for internet protocol addresses (both IPv4 and IPv6).
 module GenericParser.IPAddress where
 
-import Prelude (Ordering(..), compare, (==), (<>), (<), (+), (-), bind, pure, ($), (<<<), (>), show, map, unit)
+import Prelude (Ordering(..), compare, (==), (<>), (<), (+), (-), between, bind, pure, ($), (<<<), (>), show, map, unit)
 
 import Control.Alt ((<|>))
 import Data.Array as A
@@ -12,7 +12,7 @@ import GenericParser.Parser (Parser(..)
                             , failureError
                             , current_position
                             , string
-                            , many1, lookahead
+                            , read_input, many1, lookahead
                             , char)
 import GenericParser.BaseFunctions (repeat)
 import GenericParser.SomeParsers (nat)
@@ -23,6 +23,7 @@ data IPv6Error
   | IP6NotEnoughChunks
   | IP6TooManyChunks
   | IP6IrrelevantShortRepresentation
+  | IP6InvalidRange
 
 -- | `ipv6_chunk` parses just a group of hexadecimal characters.
 -- | Return an error (IP6TooManyHexaDecimalCharacters) in case the group has more than 4 characters.
@@ -79,9 +80,22 @@ ipv6_shortened =
 ipv6 :: Parser IPv6Error String
 ipv6 = ipv6_shortened <|> ipv6_full
 
+-- | `ipv6_range` parses an ipv6 range, such as "2001::1/56".
+-- | If the parsing succeed, the whole string is returned.
+ipv6_range :: Parser IPv6Error String
+ipv6_range =
+  read_input do _ <- ipv6
+                _ <- char '/'
+                pos <- current_position
+                n <- nat
+                if between 0 128 n
+                then pure ""
+                else Parser \_ -> failureError pos (Just IP6InvalidRange)
+
 data IPv4Error
   = IP4NumberTooBig Int
   | IP4IrrelevantShortRepresentation
+  | IP4InvalidRange
 
 -- | `ipv4_byte` a parser for 0 to 255 natural integers, which is part of the representation of an IPv4 address.
 ipv4_byte :: Parser IPv4Error Int
@@ -127,3 +141,15 @@ ipv4_shortened =
 
 ipv4 :: Parser IPv4Error String
 ipv4 = ipv4_shortened <|> ipv4_generic4bytes
+
+-- | `ipv4_range` parses an ipv4 range, such as "192.0.2.0/24".
+-- | If the parsing succeed, the whole string is returned.
+ipv4_range :: Parser IPv4Error String
+ipv4_range =
+  read_input do _ <- ipv4
+                _ <- char '/'
+                pos <- current_position
+                n <- nat
+                if between 0 32 n
+                then pure ""
+                else Parser \_ -> failureError pos (Just IP4InvalidRange)
diff --git a/test/Main.purs b/test/Main.purs
index 7edd797..3ce615b 100644
--- a/test/Main.purs
+++ b/test/Main.purs
@@ -73,10 +73,12 @@ showerror_ipv6 (IP.IP6TooManyHexaDecimalCharacters) = "TooManyHexaDecimalCharact
 showerror_ipv6 (IP.IP6NotEnoughChunks)              = "NotEnoughChunks"
 showerror_ipv6 (IP.IP6TooManyChunks)                = "TooManyChunks"
 showerror_ipv6 IP.IP6IrrelevantShortRepresentation  = "useless double dots"
+showerror_ipv6 IP.IP6InvalidRange                   = "invalid IPv6 range"
 
 showerror_ipv4 :: IP.IPv4Error -> String
 showerror_ipv4 (IP4NumberTooBig x) = "value '" <> show x <> "' is > 255"
 showerror_ipv4 IP4IrrelevantShortRepresentation = "useless double dots"
+showerror_ipv4 IP4InvalidRange                  = "invalid IPv4 range"
 
 showerror_email :: EA.EmailError -> String
 showerror_email EA.InvalidCharacter = "InvalidCharacter"
@@ -125,3 +127,11 @@ main = do
 
   log "Does parsers behave correctly (give the exact same input)?"
   foreachE T.valid_email_addresses_short (\s -> compare_parsers "E.address" (P.read_input E.address) E.address s)
+
+  log ""
+  let ip4ranges = [ "10.0.0.1/24", "192.168.0.1/32", "1.2.3.4/0", "192.168.0.1/33" ]
+  test_series "IP.ipv4_range" IP.ipv4_range id showerror_ipv4 ip4ranges
+
+  log ""
+  let ip6ranges = [ "2001::1/56", "2001:1:1::1/0", "::1/128", "::1/129" ]
+  test_series "IP.ipv6_range" IP.ipv6_range id showerror_ipv6 ip6ranges