diff --git a/liteeth/common.py b/liteeth/common.py
index 3507764e9..b95c5a0b6 100644
--- a/liteeth/common.py
+++ b/liteeth/common.py
@@ -142,6 +142,13 @@ def eth_ipv4_user_description(dw):
 	]
 	return EndpointDescription(layout, packetized=True)
 
+def convert_ip(s):
+	ip = 0
+	for e in s.split("."):
+		ip = ip << 8
+		ip += int(e)
+	return ip
+
 def eth_udp_description(dw):
 	layout = _layout_from_header(udp_header) + [
 		("data", dw),
diff --git a/targets/udpip.py b/targets/udpip.py
index e584c90fc..a9c59e102 100644
--- a/targets/udpip.py
+++ b/targets/udpip.py
@@ -175,7 +175,7 @@ class UDPIPSoC(GenSoC, AutoCSR):
 
 		# Ethernet PHY and UDP/IP
 		self.submodules.ethphy = LiteEthPHYGMII(platform.request("eth_clocks"), platform.request("eth"))
-		self.submodules.udpip_core = LiteEthUDPIPCore(self.ethphy, 0x12345678, 0x10e2d5000000)
+		self.submodules.udpip_core = LiteEthUDPIPCore(self.ethphy, convert_ip("192.168.1.40"), 0x10e2d5000000)
 
 		# BIST
 		self.submodules.bist_generator = UDPIPBISTGenerator()