1. CS492b Project #3-2 KIP router KAIST Dept. of CS NC Lab

2. Overall Architecture Client STCP KIP Server STCP KIP Actual Client Router Actual Server 5.0.0.2 5.0.0.1 194.168.1.1 194.168.1.2 UDPTunnelKIPSTCPData

3. Details Uses simulated IP address  Use the IP address in the architecture Router has the role of Server FTP client/server is actually clients of The router FTP server/client connect to the router  Execution order is important (router->server->client) To get rid of L2 layer, tunnel header has next hop address KIP has destination IP address(not changed)

4. Details- Tunnel Header KTCP/IP has not L2 Layer  For Hop-by-hop datagram forwarding, Tunnel Header is needed Tunnel Header is Like L2 Header  IP address in Tunnel header is changed on each hop

5. Modifications When sending a packet, Based on dst_ip, Do Rtable_search(next_hop, dst_ip) Then make a tunnel header with next_hop address

6. Router(1/2) Router has 2 Sockets  one from FTP Client  one from FTP Server it should be executed first Read a file for static routing table (txt. file)  Hard-coded  Has host’s IP address Generates a file including its IP address (txt. file)  has router’s IP address Client/Server first reads the file for the connection Make a log file  Record IP header & time received for each packet

7. Router(2/2) Basically, It’s the same as KIP When receiving packets, first look at the tunnel header  If destination address is Router’s address, forwards the packet Look up routing table  If not, just drop it

8. Routing Table(1/2) Uses RouteEntry  Struct RouteEntry{ ip; / ip address mask; /network mask router; /next hop if not directly connected devindex; / network interface index }

9. Tunnel Header typedef struct iptunnelheader { IPAddr dst; IPAddr src; short size; / size of data/ char* data; /actual payload/ } IPTunnelHeader

10. Schedule & Deliverables Due Date : 9 th Nov.(midnight) Commented your full source code (e-mail)  Including your Makefile Report (hard copy & thru e-mail)  Describe about your design in detail About functions you made for this project  Describe what works and what does not  Describe any peculiar strategies that you have used Demonstration (will be scheduled)

11. Tip Study UDP socket functions  If you want to connect two sockets in TCP way, Use connect() at both ends Or Use address structure Do NOT confuse virtual IP address with real IP address  Virtual IP address is the one that KIP can understand