一、定义

SLA 服务水平协议(简称:SLA,全称:service level agreement)是在一定开销下为保障服务的性能和可靠性,服务提供商与用户间定义的一种双方认可的协定。通常这个开销是驱动提供服务质量的主要因素。

简单点说就是通过发送测试报文,对网络性能,服务质量进行分析,并为用户提供网络服务质量的各种参数,例如:抖动延迟,文件传输速率,TCP时延等等

二、主要配置命令

ip sla monitor operation-number//定义SLA的编号

type echo protocol ipIcmpEcho {destination-ip-address |destination-hostname} [source-ipaddr {ip-address |hostname} | source-interface interface-name]//定义icmp测试的目的地址和源地址(我这里做实验的是用icmp其实type后可以用很多协议的很强大)

ip sla monitor schedule operation-number [life {foreverseconds}] [start-time {hh:mm[:ss] [month day | daymonth] | pending | now | after hh:mm:ss] [ageoutseconds] [recurring]//调用SLA运行的时间

三、实验

拓扑

 

实验要求:

  R1连接到ISP-1ISP-2,其中连到ISP-1的是主路径,到ISP-2是备用路径。当连接到ISP-1链路出现故障时,正常的数据流量可以通过ISP-2过。

  R1配置如下:

interface FastEthernet1/0

ip address 192.168.2.1 255.255.255.0

interface FastEthernet1/1

ip address 192.168.1.1 255.255.255.0

 

ip sla monitor 10

 type echo protocol ipIcmpEcho 192.168.2.2 source-interface FastEthernet1/0

 frequency 5  //每隔5秒测试一次

ip sla monitor schedule 10 life forever start-time now

 

 

ip sla monitor 11

 type echo protocol ipIcmpEcho 192.168.1.1 source-interface FastEthernet1/1

 frequency 5

ip sla monitor schedule 11 life forever start-time now

 

track 1 rtr 10 reachability//定义一个track跟踪目的地的可达性以便在静态路由的时候调用

track 2 rtr 11 reachability//同上

 

浮动路由:

ip route 0.0.0.0 0.0.0.0 192.168.2.2 track 1//主链路

ip route 0.0.0.0 0.0.0.0 192.168.1.2 2 track 2//备份链路

 

实验调试:

R1#debug ip sla monitor trace   //打开sla跟踪调试

R1#debug ip routing  //打开路由调试 等下会看到路由表的变化

IP routing debugging is on

R1#debug ip sla monitor trace

IP SLA Monitor TRACE debugging for all operation is on

R1#

*Mar  1 01:02:56.663: IP SLA Monitor(11) Scheduler: Starting an operation

*Mar  1 01:02:56.667: IP SLA Monitor(11) echo operation: Sending an echo operation

*Mar  1 01:02:56.675: IP SLA Monitor(11) echo operation: RTT=8

*Mar  1 01:02:56.679: IP SLA Monitor(11) Scheduler: Updating result

*Mar  1 01:02:56.915: IP SLA Monitor(10) Scheduler: Starting an operation

*Mar  1 01:02:56.915: IP SLA Monitor(10) echo operation: Sending an echo operation

*Mar  1 01:02:56.923: IP SLA Monitor(10) echo operation: RTT=4

*Mar  1 01:02:56.927: IP SLA Monitor(10) Scheduler: Updating result

R1#

*Mar  1 01:03:01.663: IP SLA Monitor(11) Scheduler: Starting an operation

*Mar  1 01:03:01.667: IP SLA Monitor(11) echo operation: Sending an echo operation

*Mar  1 01:03:01.675: IP SLA Monitor(11) echo operation: RTT=8

*Mar  1 01:03:01.675: IP SLA Monitor(11) Scheduler: Updating result

*Mar  1 01:03:01.915: IP SLA Monitor(10) Scheduler: Starting an operation

*Mar  1 01:03:01.915: IP SLA Monitor(10) echo operation: Sending an echo operation

R1#

*Mar  1 01:03:04.459: RT: NET-RED 0.0.0.0/0

R1#

*Mar  1 01:03:06.663: IP SLA Monitor(11) Scheduler: Starting an operation

*Mar  1 01:03:06.667: IP SLA Monitor(11) echo operation: Sending an echo operation

*Mar  1 01:03:06.675: IP SLA Monitor(11) echo operation: RTT=8

*Mar  1 01:03:06.679: IP SLA Monitor(11) Scheduler: Updating result

*Mar  1 01:03:06.919: IP SLA Monitor(10) echo operation: Timeout  //跟踪出现timeout

*Mar  1 01:03:06.919: IP SLA Monitor(10) Scheduler: Updating result

R1#

*Mar  1 01:03:11.331: RT: del 0.0.0.0 via 192.168.2.2, static metric [1/0]

*Mar  1 01:03:11.335: RT: delete network route to 0.0.0.0

*Mar  1 01:03:11.339: RT: NET-RED 0.0.0.0/0

*Mar  1 01:03:11.339: RT: NET-RED 0.0.0.0/0

*Mar  1 01:03:11.339: RT: SET_LAST_RDB for 0.0.0.0/0

  NEW rdb: via 192.168.1.2

 

*Mar  1 01:03:11.343: RT: add 0.0.0.0/0 via 192.168.1.2, static metric [2/0]

*Mar  1 01:03:11.343: RT: NET-RED 0.0.0.0/0

*Mar  1 01:03:11.343: RT: default path is now 0.0.0.0 via 192.168.1.2

*Mar  1 01:03:11.343: RT: new default network 0.0.0.0

*Mar  1 01:03:11.343: RT: NET-RED 0.0.0.0/0  //静态路由变成了备用路径

*Mar  1 01:03:11.663: IP SLA Monitor(11) Scheduler: Starting an operation

R1#

*Mar  1 01:03:11.663: IP SLA Monitor(11) echo operation: Sending an echo operation

*Mar  1 01:03:11.675: IP SLA Monitor(11) echo operation: RTT=8

*Mar  1 01:03:11.679: IP SLA Monitor(11) Scheduler: Updating result

*Mar  1 01:03:11.919: IP SLA Monitor(10) Scheduler: Starting an operation

*Mar  1 01:03:11.919: IP SLA Monitor(10) echo operation: Sending an echo operation

R1#

*Mar  1 01:03:16.663: IP SLA Monitor(11) Scheduler: Starting an operation

*Mar  1 01:03:16.667: IP SLA Monitor(11) echo operation: Sending an echo operation

*Mar  1 01:03:16.675: IP SLA Monitor(11) echo operation: RTT=8

*Mar  1 01:03:16.679: IP SLA Monitor(11) Scheduler: Updating result

*Mar  1 01:03:16.919: IP SLA Monitor(10) echo operation: Timeout

*Mar  1 01:03:16.919: IP SLA Monitor(10) Scheduler: Updating result

R1#u all

All possible debugging has been turned off

R1#

*Mar  1 01:03:21.663: IP SLA Monitor(11) Scheduler: Starting an operation

*Mar  1 01:03:21.663: IP SLA Monitor(11) echo operation: Sending an echo operation

*Mar  1 01:03:21.663: IP SLA Monitor(11) echo operation: RTT=1

*Mar  1 01:03:21.663: IP SLA Monitor(11) Scheduler: Updating result

R1#sho ip rou

R1#sho ip route

Codes: C - connected, S - static, R - RIP, M - mobile, B - BGP

       D - EIGRP, EX - EIGRP external, O - OSPF, IA - OSPF inter area

       N1 - OSPF NSSA external type 1, N2 - OSPF NSSA external type 2

       E1 - OSPF external type 1, E2 - OSPF external type 2

       i - IS-IS, su - IS-IS summary, L1 - IS-IS level-1, L2 - IS-IS level-2

       ia - IS-IS inter area, * - candidate default, U - per-user static route

       o - ODR, P - periodic downloaded static route

 

Gateway of last resort is 192.168.1.2 to network 0.0.0.0

 

C    192.168.1.0/24 is directly connected, FastEthernet1/1

C    192.168.2.0/24 is directly connected, FastEthernet1/0

S*   0.0.0.0/0 [2/0] via 192.168.1.2 //备用路径出现在路由表、

注:当主链路恢复时又会重新出现时,主路径又会替换掉备用路径!!!

实验的主要思想:结合SLA能测试链路的各种参数,来实现路径的控制,或者是冗余路径。

SLA的功能肯定不是这一点点,鉴于本人也只是刚刚开始看SLA,这个小实验提供给大家初步了解SLA