diff --git a/Makefile b/Makefile
index d3e8ec0..484550a 100644
--- a/Makefile
+++ b/Makefile
@@ -5,8 +5,8 @@ TEST_CXXFLAGS := $(CXXFLAGS) -I./googletest/include/
 
 all: dpnet.dll
 
-dpnet.dll: src/dpnet.o src/dpnet.def src/DirectPlay8Address.o src/DirectPlay8Peer.o
-	$(CXX) $(CXXFLAGS) -Wl,--enable-stdcall-fixup -shared -o $@ $^ -ldxguid -static-libstdc++ -static-libgcc
+dpnet.dll: src/dpnet.o src/dpnet.def src/DirectPlay8Address.o src/DirectPlay8Peer.o src/network.o
+	$(CXX) $(CXXFLAGS) -Wl,--enable-stdcall-fixup -shared -o $@ $^ -ldxguid -lws2_32 -static-libstdc++ -static-libgcc
 
 tests/DirectPlay8Address.exe: tests/DirectPlay8Address.o src/DirectPlay8Address.o googletest/src/gtest-all.o googletest/src/gtest_main.o
 	$(CXX) $(TEST_CXXFLAGS) -o $@ $^  -ldxguid -lole32 -static-libstdc++ -static-libgcc
diff --git a/src/DirectPlay8Peer.cpp b/src/DirectPlay8Peer.cpp
index ed2a91a..edc58da 100644
--- a/src/DirectPlay8Peer.cpp
+++ b/src/DirectPlay8Peer.cpp
@@ -1,10 +1,14 @@
+#include <winsock2.h>
 #include <atomic>
 #include <dplay8.h>
 #include <objbase.h>
+#include <stdint.h>
 #include <stdio.h>
 #include <windows.h>
 
+#include "DirectPlay8Address.hpp"
 #include "DirectPlay8Peer.hpp"
+#include "network.hpp"
 
 #define UNIMPLEMENTED(fmt, ...) \
 	fprintf(stderr, "Unimplemented method: " fmt "\n", ## __VA_ARGS__); \
@@ -12,11 +16,17 @@
 
 DirectPlay8Peer::DirectPlay8Peer(std::atomic<unsigned int> *global_refcount):
 	global_refcount(global_refcount),
-	local_refcount(0)
+	local_refcount(0),
+	state(STATE_DISCONNECTED),
+	udp_socket(-1),
+	listener_socket(-1),
+	discovery_socket(-1)
 {
 	AddRef();
 }
 
+DirectPlay8Peer::~DirectPlay8Peer() {}
+
 HRESULT DirectPlay8Peer::QueryInterface(REFIID riid, void **ppvObject)
 {
 	if(riid == IID_IDirectPlay8Peer || riid == IID_IUnknown)
@@ -61,7 +71,10 @@ ULONG DirectPlay8Peer::Release(void)
 
 HRESULT DirectPlay8Peer::Initialize(PVOID CONST pvUserContext, CONST PFNDPNMESSAGEHANDLER pfn, CONST DWORD dwFlags)
 {
-	UNIMPLEMENTED("DirectPlay8Peer::Initialize");
+	message_handler     = pfn;
+	message_handler_ctx = pvUserContext;
+	
+	return S_OK;
 }
 
 HRESULT DirectPlay8Peer::EnumServiceProviders(CONST GUID* CONST pguidServiceProvider, CONST GUID* CONST pguidApplication, DPN_SERVICE_PROVIDER_INFO* CONST pSPInfoBuffer, DWORD* CONST pcbEnumData, DWORD* CONST pcReturned, CONST DWORD dwFlags)
@@ -91,17 +104,192 @@ HRESULT DirectPlay8Peer::GetSendQueueInfo(CONST DPNID dpnid, DWORD* CONST pdwNum
 
 HRESULT DirectPlay8Peer::Host(CONST DPN_APPLICATION_DESC* CONST pdnAppDesc, IDirectPlay8Address **CONST prgpDeviceInfo, CONST DWORD cDeviceInfo, CONST DPN_SECURITY_DESC* CONST pdnSecurity, CONST DPN_SECURITY_CREDENTIALS* CONST pdnCredentials, void* CONST pvPlayerContext, CONST DWORD dwFlags)
 {
-	UNIMPLEMENTED("DirectPlay8Peer::Host");
+	if(state != STATE_DISCONNECTED)
+	{
+		return DPNERR_ALREADYCONNECTED;
+	}
+	
+	if(pdnAppDesc->dwSize != sizeof(DPN_APPLICATION_DESC))
+	{
+		return DPNERR_INVALIDPARAM;
+	}
+	
+	if(pdnAppDesc->dwFlags & DPNSESSION_CLIENT_SERVER)
+	{
+		return DPNERR_INVALIDPARAM;
+	}
+	
+	if(pdnAppDesc->dwFlags & DPNSESSION_MIGRATE_HOST)
+	{
+		/* Not supported yet. */
+	}
+	
+	application_guid = pdnAppDesc->guidApplication;
+	max_players      = pdnAppDesc->dwMaxPlayers;
+	session_name     = pdnAppDesc->pwszSessionName;
+	
+	if(pdnAppDesc->dwFlags & DPNSESSION_REQUIREPASSWORD)
+	{
+		password = pdnAppDesc->pwszPassword;
+	}
+	else{
+		password.clear();
+	}
+	
+	application_data.clear();
+	
+	if(pdnAppDesc->pvApplicationReservedData != NULL && pdnAppDesc->dwApplicationReservedDataSize > 0)
+	{
+		application_data.insert(application_data.begin(),
+			(unsigned char*)(pdnAppDesc->pvApplicationReservedData),
+			(unsigned char*)(pdnAppDesc->pvApplicationReservedData) + pdnAppDesc->dwApplicationReservedDataSize);
+	}
+	
+	uint32_t ipaddr = htonl(INADDR_ANY);
+	uint16_t port   = 0;
+	
+	for(DWORD i = 0; i < cDeviceInfo; ++i)
+	{
+		DirectPlay8Address *addr = (DirectPlay8Address*)(prgpDeviceInfo[i]);
+		
+		DWORD addr_port_value;
+		DWORD addr_port_size = sizeof(addr_port_value);
+		DWORD addr_port_type;
+		
+		if(addr->GetComponentByName(DPNA_KEY_PORT, &addr_port_value, &addr_port_size, &addr_port_type) == S_OK
+			&& addr_port_type == DPNA_DATATYPE_DWORD)
+		{
+			if(port != 0 && port != addr_port_value)
+			{
+				/* Multiple ports specified, don't support this yet. */
+				return DPNERR_INVALIDPARAM;
+			}
+			else{
+				port = addr_port_value;
+			}
+		}
+	}
+	
+	if(port == 0)
+	{
+		port = DEFAULT_HOST_PORT;
+	}
+	
+	udp_socket      = create_udp_socket     (ipaddr, port);
+	listener_socket = create_listener_socket(ipaddr, port);
+	
+	if(udp_socket == -1 || listener_socket == -1)
+	{
+		return DPNERR_GENERIC;
+	}
+	
+	if(!(pdnAppDesc->dwFlags & DPNSESSION_NODPNSVR))
+	{
+		discovery_socket = create_discovery_socket();
+	}
+	
+	state = STATE_HOSTING;
+	
+	return S_OK;
 }
 
 HRESULT DirectPlay8Peer::GetApplicationDesc(DPN_APPLICATION_DESC* CONST pAppDescBuffer, DWORD* CONST pcbDataSize, CONST DWORD dwFlags)
 {
-	UNIMPLEMENTED("DirectPlay8Peer::GetApplicationDesc");
+	if(state == STATE_DISCONNECTED)
+	{
+		return DPNERR_NOCONNECTION;
+	}
+	
+	DWORD required_size = sizeof(DPN_APPLICATION_DESC)
+		+ (password.length() + !password.empty()) * sizeof(wchar_t)
+		+ application_data.size();
+	
+	if(pAppDescBuffer != NULL && *pcbDataSize >= required_size)
+	{
+		unsigned char *extra_at = (unsigned char*)(pAppDescBuffer);
+		
+		pAppDescBuffer->dwSize = sizeof(*pAppDescBuffer);
+		pAppDescBuffer->dwFlags = 0;
+		pAppDescBuffer->guidInstance     = instance_guid;
+		pAppDescBuffer->guidApplication  = application_guid;
+		pAppDescBuffer->dwMaxPlayers     = max_players;
+		pAppDescBuffer->dwCurrentPlayers = peers.size() + 1;
+		
+		if(!password.empty())
+		{
+			wcscpy((wchar_t*)(extra_at), password.c_str());
+			
+			pAppDescBuffer->dwFlags |= DPNSESSION_REQUIREPASSWORD;
+			pAppDescBuffer->pwszPassword = (wchar_t*)(extra_at);
+			
+			extra_at += (password.length() + 1) * sizeof(wchar_t);
+		}
+		else{
+			pAppDescBuffer->pwszPassword = NULL;
+		}
+		
+		pAppDescBuffer->pvReservedData     = NULL;
+		pAppDescBuffer->dwReservedDataSize = 0;
+		
+		if(!application_data.empty())
+		{
+			memcpy(extra_at, application_data.data(), application_data.size());
+			
+			pAppDescBuffer->pvApplicationReservedData     = extra_at;
+			pAppDescBuffer->dwApplicationReservedDataSize = application_data.size();
+			
+			extra_at += application_data.size();
+		}
+		else{
+			pAppDescBuffer->pvApplicationReservedData     = NULL;
+			pAppDescBuffer->dwApplicationReservedDataSize = 0;
+		}
+		
+		return S_OK;
+	}
+	else{
+		*pcbDataSize = sizeof(*pAppDescBuffer);
+		return DPNERR_BUFFERTOOSMALL;
+	}
 }
 
 HRESULT DirectPlay8Peer::SetApplicationDesc(CONST DPN_APPLICATION_DESC* CONST pad, CONST DWORD dwFlags)
 {
-	UNIMPLEMENTED("DirectPlay8Peer::SetApplicationDesc");
+	if(state == STATE_HOSTING)
+	{
+		if(pad->dwMaxPlayers > 0 && pad->dwMaxPlayers <= peers.size())
+		{
+			/* Can't set dwMaxPlayers below current player count. */
+			return DPNERR_INVALIDPARAM;
+		}
+		
+		max_players  = pad->dwMaxPlayers;
+		session_name = pad->pwszSessionName;
+		
+		if(pad->dwFlags & DPNSESSION_REQUIREPASSWORD)
+		{
+			password = pad->pwszPassword;
+		}
+		else{
+			password.clear();
+		}
+		
+		application_data.clear();
+		
+		if(pad->pvApplicationReservedData != NULL && pad->dwApplicationReservedDataSize > 0)
+		{
+			application_data.insert(application_data.begin(),
+				(unsigned char*)(pad->pvApplicationReservedData),
+				(unsigned char*)(pad->pvApplicationReservedData) + pad->dwApplicationReservedDataSize);
+		}
+		
+		/* TODO: Notify peers */
+		
+		return S_OK;
+	}
+	else{
+		return DPNERR_NOTHOST;
+	}
 }
 
 HRESULT DirectPlay8Peer::CreateGroup(CONST DPN_GROUP_INFO* CONST pdpnGroupInfo, void* CONST pvGroupContext, void* CONST pvAsyncContext, DPNHANDLE* CONST phAsyncHandle, CONST DWORD dwFlags)
@@ -144,9 +332,9 @@ HRESULT DirectPlay8Peer::EnumGroupMembers(CONST DPNID dpnid, DPNID* CONST prgdpn
 	UNIMPLEMENTED("DirectPlay8Peer::EnumGroupMembers");
 }
 
-HRESULT DirectPlay8Peer::SetPeerInfo(CONST DPN_PLAYER_INFO* CONST pdpnPlayerInfo,PVOID CONST pvAsyncContext, DPNHANDLE* CONST phAsyncHandle, CONST DWORD dwFlags)
+HRESULT DirectPlay8Peer::SetPeerInfo(CONST DPN_PLAYER_INFO* CONST pdpnPlayerInfo, PVOID CONST pvAsyncContext, DPNHANDLE* CONST phAsyncHandle, CONST DWORD dwFlags)
 {
-	UNIMPLEMENTED("DirectPlay8Peer::SetPeerInfo");
+	UNIMPLEMENTED("DirectPlay8Peer::SetPeerInfo(%p, %p, %p, %u)", pdpnPlayerInfo, pvAsyncContext, phAsyncHandle, (unsigned)(dwFlags));
 }
 
 HRESULT DirectPlay8Peer::GetPeerInfo(CONST DPNID dpnid, DPN_PLAYER_INFO* CONST pdpnPlayerInfo, DWORD* CONST pdwSize, CONST DWORD dwFlags)
diff --git a/src/DirectPlay8Peer.hpp b/src/DirectPlay8Peer.hpp
index 2e218ff..3e13bcb 100644
--- a/src/DirectPlay8Peer.hpp
+++ b/src/DirectPlay8Peer.hpp
@@ -3,7 +3,9 @@
 
 #include <atomic>
 #include <dplay8.h>
+#include <map>
 #include <objbase.h>
+#include <stdint.h>
 
 class DirectPlay8Peer: public IDirectPlay8Peer
 {
@@ -11,9 +13,43 @@ class DirectPlay8Peer: public IDirectPlay8Peer
 		std::atomic<unsigned int> * const global_refcount;
 		ULONG local_refcount;
 		
+		PFNDPNMESSAGEHANDLER message_handler;
+		PVOID message_handler_ctx;
+		
+		enum {
+			STATE_DISCONNECTED,
+			STATE_HOSTING,
+			STATE_CONNECTED,
+		} state;
+		
+		GUID instance_guid;
+		GUID application_guid;
+		DWORD max_players;
+		std::wstring session_name;
+		std::wstring password;
+		std::vector<unsigned char> application_data;
+		
+		int udp_socket;        /* UDP socket, used for general send/recv operations. */
+		int listener_socket;   /* TCP listener socket. */
+		int discovery_socket;  /* Discovery UDP sockets, RECIEVES broadcasts only. */
+		
+		struct Player
+		{
+			/* This is the TCP socket to the peer, we may have connected to it, or it
+			 * may have connected to us depending who joined the session first, that
+			 * doesn't really matter.
+			*/
+			int sock;
+			
+			uint32_t ip;    /* IPv4 address, network byte order. */
+			uint16_t port;  /* Port, host byte order. */
+		};
+		
+		std::map<DPNID, Player> peers;
+		
 	public:
 		DirectPlay8Peer(std::atomic<unsigned int> *global_refcount);
-		virtual ~DirectPlay8Peer() {}
+		virtual ~DirectPlay8Peer();
 		
 		/* IUnknown */
 		virtual HRESULT STDMETHODCALLTYPE QueryInterface(REFIID riid, void **ppvObject) override;
diff --git a/src/network.cpp b/src/network.cpp
new file mode 100644
index 0000000..dae0d25
--- /dev/null
+++ b/src/network.cpp
@@ -0,0 +1,91 @@
+#include <winsock2.h>
+#include <windows.h>
+#include <stdint.h>
+
+#include "network.hpp"
+
+int create_udp_socket(uint32_t ipaddr, uint16_t port)
+{
+	int sock = socket(AF_INET, SOCK_DGRAM, 0);
+	if(sock == -1)
+	{
+		return -1;
+	}
+	
+	BOOL broadcast = TRUE;
+	if(setsockopt(sock, SOL_SOCKET, SO_BROADCAST, (char*)(&broadcast), sizeof(BOOL)) == -1)
+	{
+		closesocket(sock);
+		return -1;
+	}
+	
+	struct sockaddr_in addr;
+	addr.sin_family      = AF_INET;
+	addr.sin_addr.s_addr = ipaddr;
+	addr.sin_port        = htons(port);
+	
+	if(bind(sock, (struct sockaddr*)(&addr), sizeof(addr)) == -1)
+	{
+		closesocket(sock);
+		return -1;
+	}
+	
+	return sock;
+}
+
+int create_listener_socket(uint32_t ipaddr, uint16_t port)
+{
+	int sock = socket(AF_INET, SOCK_DGRAM, 0);
+	if(sock == -1)
+	{
+		return -1;
+	}
+	
+	struct sockaddr_in addr;
+	addr.sin_family      = AF_INET;
+	addr.sin_addr.s_addr = ipaddr;
+	addr.sin_port        = htons(port);
+	
+	if(bind(sock, (struct sockaddr*)(&addr), sizeof(addr)) == -1)
+	{
+		closesocket(sock);
+		return -1;
+	}
+	
+	if(listen(sock, LISTEN_QUEUE_SIZE) == -1)
+	{
+		closesocket(sock);
+		return -1;
+	}
+	
+	return sock;
+}
+
+int create_discovery_socket()
+{
+	int sock = socket(AF_INET, SOCK_DGRAM, 0);
+	if(sock == -1)
+	{
+		return -1;
+	}
+	
+	BOOL reuse = TRUE;
+	if(setsockopt(sock, SOL_SOCKET, SO_REUSEADDR, (char*)(&reuse), sizeof(BOOL)) == -1)
+	{
+		closesocket(sock);
+		return -1;
+	}
+	
+	struct sockaddr_in addr;
+	addr.sin_family      = AF_INET;
+	addr.sin_addr.s_addr = htonl(INADDR_ANY);
+	addr.sin_port        = htons(DISCOVERY_PORT);
+	
+	if(bind(sock, (struct sockaddr*)(&addr), sizeof(addr)) == -1)
+	{
+		closesocket(sock);
+		return -1;
+	}
+	
+	return sock;
+}
diff --git a/src/network.hpp b/src/network.hpp
new file mode 100644
index 0000000..31cfdc1
--- /dev/null
+++ b/src/network.hpp
@@ -0,0 +1,14 @@
+#ifndef DPLITE_NETWORK_HPP
+#define DPLITE_NETWORK_HPP
+
+#include <stdint.h>
+
+#define DISCOVERY_PORT    6073
+#define DEFAULT_HOST_PORT 6072
+#define LISTEN_QUEUE_SIZE 16
+
+int create_udp_socket(uint32_t ipaddr, uint16_t port);
+int create_listener_socket(uint32_t ipaddr, uint16_t port);
+int create_discovery_socket();
+
+#endif /* !DPLITE_NETWORK_HPP */