diff --git a/docs/network.rst b/docs/network.rst
index 7be09fb..e4f72b6 100644
--- a/docs/network.rst
+++ b/docs/network.rst
@@ -42,3 +42,23 @@ Network
     >>> from pydu.network import get_free_port
     >>> get_free_port()
     57118
+
+
+.. py:function:: pydu.network.ip2int(ip_str)
+
+    Convert ip to integer. Support IPV4 and IPV6.
+    Raise ``ValueError`` if convert failed.
+
+    >>> from pydu.network import ip2int
+    >>> ip2int('10.1.1.1')
+    167837953
+
+
+.. py:function:: pydu.network.int2ip(ip_int)
+
+    Convert integer to ip. Support IPV4 and IPV6.
+    Raise ``ValueError`` if convert failed.
+
+    >>> from pydu.network import int2ip
+    >>> int2ip(167837953)
+    '10.1.1.1'
diff --git a/pydu/network.py b/pydu/network.py
index 0fe951b..f00b578 100644
--- a/pydu/network.py
+++ b/pydu/network.py
@@ -123,6 +123,10 @@ def get_free_port():
 # https://stackoverflow.com/questions/5619685/conversion-from-ip-string-to-integer-and-backward-in-python
 # https://stackoverflow.com/questions/11894717/python-convert-ipv6-to-an-integer
 def ip2int(ip_str):
+    """
+    Convert ip to integer. Support IPV4 and IPV6.
+    Raise `ValueError` if convert failed.
+    """
     try:
         return struct.unpack("!I", socket.inet_aton(ip_str))[0]
     except socket.error:
@@ -138,6 +142,10 @@ def ip2int(ip_str):
 
 # https://stackoverflow.com/questions/5619685/conversion-from-ip-string-to-integer-and-backward-in-python
 def int2ip(ip_int):
+    """
+    Convert integer to ip. Support IPV4 and IPV6.
+    Raise `ValueError` if convert failed.
+    """
     try:
         return socket.inet_ntoa(struct.pack("!I", ip_int))
     except (socket.error, struct.error):