Red Hat Enterprise Linux 5 Administration Unleashed

Reporting on the Network Subsystem 415LISTING 20.10Continued297864 free swap2638363 non-nice user cpu ticks3764 nice user cpu ticks503661 system cpu ticks78527688 idle cpu ticks647000 IO-wait cpu ticks26495 IRQ cpu ticks0 softirq cpu ticks40496151 pages paged in16937888 pages paged out678133 pages swapped in399395 pages swapped out840250343 interrupts326447770 CPU context switches1135738065 boot time109526 forksReporting on the Network SubsystemIn an enterprise company with offices all around the world, the network subsystem is oneof the most carefully monitored system resources. Without network connectivity, somecompanies could not perform their day-to-day tasks from something as simple as email tosomething more critical such as accessing patient records.While ifconfig can be used to configure network devices as discussed in Chapter 2,“Post-Installation Configuration,” it can also be used to quickly determine if the devicehas an IP address or to retrieve the MAC address of an interface as shown in Listing 20.11.LISTING 20.11Example Output from ifconfigeth0Link encap:Ethernet HWaddr 00:A0:CC:28:3D:44inet addr:192.168.0.4 Bcast:192.168.0.255 Mask:255.255.255.0inet6 addr: fe80::2a0:ccff:fe28:3d44/64 Scope:LinkUP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1RX packets:1699162 errors:1 dropped:0 overruns:0 frame:0TX packets:2743880 errors:3 dropped:0 overruns:3 carrier:0collisions:3153 txqueuelen:1000RX bytes:335440321 (319.9 MiB) TX bytes:3356790591 (3.1 GiB)Interrupt:9 Base address:0x6c0020loLink encap:Local Loopbackinet addr:127.0.0.1 Mask:255.0.0.0inet6 addr: ::1/128 Scope:HostUP LOOPBACK RUNNING MTU:16436 Metric:1