一、ip accounting

    1、配置方法

    router(config)#int s 0/0

    router(config-if)#ip accounting output-packets

    router#sh ip accounting output-packets

    Source Destination Packets Bytes

    192.1.1.110 192.1.1.97 5 500

    172.17.246. 128 192.1.1.110 8 704

    Accounting data age is 2d23h

    或者

    router(config)#int s 0/0

    router(config-if)#ip accounting access-violations

    router#sh ip accounting [checkpoint] access-violations

    Source Destination Packets Bytes ACL

    192.1.1.110 224.0.0.5 46 3128 19

    Accounting data age is 7

    2、说明

    此方法如果在路由器负载特大的时候请谨慎使用，因其会使系统性能下降；基于地址对的字节数量及数据包数量统计；通常只支持outbound的数据包，及被ACL拒绝的数据包（支持IN 和 OUT方向的ACL）；只统计穿越路由器的流量，源或目的是该路由器的数据包不做统计；支持所有的switching path，除了Autonomous Switching；可以通过SNMP来访问统计值，MIB是OLD-CISCO-IP-MIB, lipAccountingTable；ip accounting还支持其他的监测方式，如基于tos,mac-address等。

    二、netflow

    1、配置方法

    router (config-if)#ip route-cache flow

    router (config)#ip flow-export destination 172.17.246.225 9996

    router (config)#ip flow-export version 5

    Optional configuration

    router (config)#ip flow-export source loopback 0

    router (config)#ip flow-cache entries <1024-524288>

    router (config)#ip flow-cache timeout

    sh ip cache flow

    IP packet size distribution (132429191 total packets):

    1-32 64 96 128 160 192 224 256 288 320 352 384 416 448 480

    .000 .191 .024 .009 .010 .006 .005 .008 .003 .005 .003 .003 .002 .001 .001

    512 544 576 1024 1536 2048 2560 3072 3584 4096 4608

    .001 .002 .107 .032 .578 .000 .000 .000 .000 .000 .000

    IP Flow Switching Cache, 278544 bytes

    33 active, 4063 inactive, 7975259 added

    104834714 ager polls, 0 flow alloc failures

    Active flows timeout in 30 minutes

    Inactive flows timeout in 15 seconds

    last clearing of statistics never

    Protocol Total Flows Packets Bytes Packets Active(Sec) Idle(Sec)

    -------- Flows /Sec /Flow /Pkt /Sec /Flow /Flow

    TCP-Telnet 25378 0.0 12 652 0.0 22.9 15.2

    TCP-FTP 432435 0.1 4 59 0.4 1.2 2.7

    TCP-FTPD 28670 0.0 212 1397 1.4 8.2 1.6

    TCP-WWW 4682530 1.0 15 927 16.4 2.4 4.6

    2、说明

    统计基于流（包括地址对、端口号、协议类型等）的数据量；只支持inbound的流量；只支持单播；只能在主端口配置；需要和cef或fast switching一起使用；对路由器性能有影响。

    10,000 active flows: < 4% of additional CPU utilization

    45,000 active flows: <12% of additional CPU utilization

    65,000 active flows: <16% of additional CPU utilization