8.2 Code Introduction

Team-Fly     TCP/IP Illustrated, Volume 2: The Implementation By Gary R. Wright, W. Richard Stevens Table of Contents Chapter 8.  IP: Internet Protocol 8.2 Code Introduction Two headers and three C files are discussed in this chapter. Figure 8.2. Files discussed in this chapter. Global Variables Several global variables appear in the IP processing code. They are described in Figure 8.3. Figure 8.3. Global variables introduced in this chapter. Statistics All the statistics collected by IP are found in the ipstat structure described by Figure 8.4. Figure 8.5 shows some sample output of these statistics, from the netstat -s command. These statistics were collected after the host had been up for 30 days. Figure 8.4. Statistics collected in this chapter. Figure 8.5. Sample IP statistics. The value for ips_noproto is high because it can count ICMP host unreachable messages when there is no process ready to receive the messages. See Section 32.5 for more details. SNMP Variables Figure 8.6 shows the relationship between the SNMP variables in the IP group and the statistics collected by Net/3. Figure 8.6. Simple SNMP variables in IP group. Team-Fly     Top