1. TCP/IP and Unix Chuck Davin University of Pennsylvania CSE 350 22 February 2001

2. Some Recent History

3. n Resources n Planning n Dependencies n Communication n Knowledge

4. Engineering  Success n 10 to 50 Percent “failure” rate n Lots of time n Lots of money n Classroom  “Reality”

5. Audience n Embedded Software  User Software n Mass-Market  Custom

6. BSD  TCP/IP n API  Protocol n Host  Router n Host  Application Gateway n Default Router  0.0.0.0

7. Multihoming The bind () system call The bind () system call n INADDR_ANY n Defaults and Wildcards

8. BSD  OSI n BSD Sockets  SVR4 Streams Configure IP adaptation via ifconfig Configure IP adaptation via ifconfig n Configure IP via routing table Configure TCP via bind,connect Configure TCP via bind,connect n What is a BSD “Interface”? n What is a BSD “Socket”?

9. BSD Sockets n A Triumph of Abstraction n Focus on Synchronization n read (fd, buf, n) != n

10. Subnets and Routing n IP “Classic” was classful n IP Subnetting introduced ca. 1986-7 n Variable Length Subnet Masks? n Non-contiguous Subnet Masks? n Longest Match IP Routing n RIP, RIP2, OSPF, CLNP

11. Broader Horizons n RFC 791 et al. n BSD  TCP/IP