IP_SLA_CISCO

 

CISCO IP SERVICE  LEVEL AGREEMENT (SLA) :

Cisco IOS IP SLAs allow paths to be changed based on network conditions such as jitter,latency, load and other factors.

VERIFY:

R1#ping 192.168.2.2

Type escape sequence to abort.

Sending 5, 100-byte ICMP Echos to 192.168.2.2, timeout is 2 seconds:

UUUUU

Success rate is 0 percent (0/5)

R2(config)#int f0/0

R2(config-if)#shut

R2(config-if)#

R1#ping 192.168.2.2

Type escape sequence to abort.

Sending 5, 100-byte ICMP Echos to 192.168.2.2, timeout is 2 seconds:

!!!!!

Success rate is 100 percent (5/5), round-trip min/avg/max = 88/91/92 ms

*Mar 22 11:17:11.763: %TRACKING-5-STATE: 1 ip sla 1 state Down->Up

HSRP WITH  IP SLA:

 HSRP WITH  IP SLA CONFIGURATION ARE ADDITIONAL FEATURES OF BOOLEAN OBJECT

 TRACKING AND NETWORK REDUNDANCY CONFIGURATION ON CISCO ROUTER .

R1#
interface FastEthernet0/0
ip address 10.10.20.1 255.255.255.0
duplex full
!
interface FastEthernet1/0
ip address 192.168.100.10 255.255.255.0
duplex full
speed auto
standby 12 ip 192.168.100.1
standby 12 preempt
!
router ospf 1
log-adjacency-changes
passive-interface FastEthernet1/0
network 10.10.20.0 0.0.0.255 area 0
network 192.168.100.0 0.0.0.255 area 0

R2#
!
interface FastEthernet0/0
ip address 10.10.30.2 255.255.255.0
duplex full
!
interface FastEthernet1/0
ip address 192.168.100.20 255.255.255.0
duplex full
speed auto
standby 12 ip 192.168.100.1
standby 12 priority 91
!      
router ospf 1
log-adjacency-changes
passive-interface FastEthernet1/0
network 10.10.30.0 0.0.0.255 area 0
network 192.168.100.0 0.0.0.255 area 0

R3#
!
interface Loopback0
ip address 192.168.33.33 255.255.255.255
!
interface FastEthernet0/0
ip address 10.10.20.3 255.255.255.0
duplex full
!
interface FastEthernet1/0
ip address 10.10.30.3 255.255.255.0
duplex full
speed auto
!
router ospf 1
log-adjacency-changes
network 10.10.20.0 0.0.0.255 area 0
network 10.10.30.0 0.0.0.255 area 0
network 192.168.33.33 0.0.0.0 area 0
distance 254 10.10.30.2 0.0.0.0

Now, lets configure and SLA that constantly pings the Loopback address of R3 from

 R1. We will set the frequency of 10 , timeout and threshold of 2000.

R1(config)#ip sla monitor 1
R1(config-sla-monitor)#type echo protocol ipIcmpEcho 192.168.33.33
R1(config-sla-monitor-echo)#timeout 2000
R1(config-sla-monitor-echo)#threshold 2000
R1(config-sla-monitor-echo)#frequency 10

The frequency means it will do a ping in every 10 seconds to check if the configured netework is still reachable. The timeout and threshold values will determine if there is a "breach" in the configured SLA. Now let's start the SLA now and let it continue "forever" as long as the router is alive. You can also set other parameters like what time of the day this will start and what time it will end.

R1(config)#ip sla monitor schedule 1 start-time now life forever

R1#debug ip icmp
ICMP packet debugging is on
R1#
*Sep  2 10:57:31.507: ICMP: echo reply rcvd, src 192.168.33.33, dst 10.10.20.1
*Sep  2 10:57:41.523: ICMP: echo reply rcvd, src 192.168.33.33, dst 10.10.20.1
*Sep  2 10:57:51.523: ICMP: echo reply rcvd, src 192.168.33.33, dst 10.10.20.1
*Sep  2 10:58:01.547: ICMP: echo reply rcvd, src 192.168.33.33, dst 10.10.20.1

R1(config)#track 1 rtr 1 reachability
R1(config-track)#int fa1/0
R1(config-if)#standby 12 track 1 decrement 11

R1#sh ip sla monitor statistics 1
Round trip time (RTT)   Index 1
Latest RTT: 28 ms
Latest operation start time: *11:04:01.523 UTC Wed Sep 2 2009
Latest operation return code: OK
Number of successes: 42
Number of failures: 0
Operation time to live: Forever

R1#sh standby br
         P indicates configured to preempt.
         |
Interface   Grp Prio P State    Active          Standby         Virtual IP
Fa1/0       12  89   P Standby  192.168.100.20  local           192.168.100.1