IP SLA with Object Tracking Configuration example Troubleshooting

IP SLA with Object Tracking - Configuration example -Troubleshooting

Where it can be implemented • Static Routing • Hot Standby Router Protoco (HSRP) • Policy Based Routing (PBR)

When NOT to use Object Tracking • Directly connected interfaces. Tracks G 0/0 RA • Running routing protocol (i. e. RIP, OSPF, EIGRP, BGP, etc. ) RB No route being advertised RA 192. 168. 1. 0/24 200. 2. 2. 0/24 RC RD

Configuration Components IP SLA • Define IP SLA Operation Object Tracking • Link track to IP SLA Operation Objects • Link objects to track. Such as Static route, PBR, HSRP, etc.

Static Routing with Object Tracking On RA: interface Ethernet 0/0 description primary-link ip address 200. 1. 1. 2 255. 0 ! interface Ethernet 0/1 description backup-link ip address 200. 2. 2. 2 255. 0 ! ip sla 1 icmp-echo 212. 23. 1. 1 source-ip 200. 1. 1. 2 frequency 3 ip sla schedule 1 life forever start-time now track 2 ip sla 1 reachability ! ip route 0. 0 200. 1. 1. 1 track 2 ip route 0. 0 200. 2. 2. 1 250 ! access-list 101 permit icmp any host 212. 23. 1. 1 route-map LOCAL-POLICY permit 10 match ip address 101 set ip next-hop 200. 1. 1. 1 ! ip local policy route-map LOCAL-POLICY

HSRP with Object Tracking On RA (Active Router): ip sla 1 icmp-echo 4. 2. 2. 2 frequency 3 ip sla schedule 1 life forever start-time now ! track 2 ip sla 1 reachability ! interface Ethernet 0/0 ip address 10. 10. 1 255. 0 standby 1 ip 10. 10. 3 standby 1 priority 110 standby 1 preempt standby 1 track 2 decrement 15 ! access-list 101 permit icmp any host 4. 2. 2. 2 route-map LOCAL-POLICY permit 10 match ip address 101 set ip next-hop 200. 1. 1. 1 ! ip local policy route-map LOCAL-POLICY

PBR with Multiple Object Tracking On RA: ip sla 1 icmp-echo 200. 1. 1. 2 frequency 3 ip sla schedule 1 life forever start-time now ! ip sla 2 icmp-echo 200. 2. 2. 2 frequency 3 ip sla schedule 2 life forever start-time now ! track 11 ip sla 1 reachability track 22 ip sla 2 reachability ! access-list 101 permit 10. 10. 0. 0. 255 any route-map LAB permit 10 match ip addess 101 set ip next-hop verify-availability 200. 1. 1. 2 10 track 11 set ip next-hop verify-availability 200. 2. 2. 2 20 track 22 ! Interface Ethernet 1/0 ip address 10. 10. 1 255. 0 ip policy route-map LAB

Parameters • Frequency Sets the rate at which a specified Cisco IOS IP SLAs operation is sent into the network. • Timeout Sets the amount of time for which the Cisco IOS IP SLAs operation waits for a response from its request packet. • Threshold Sets the rising threshold that generates a reaction event and stores history information for the Cisco IOS IP SLAs operation. Example: ip sla 1 icmp-echo 212. 23. 1. 1 timeout 500 threshold 2 frequency 3 ip sla schedule 1 life forever start-time now

“Show” Commands for IP SLA • show ip sla statistics Displays the current state of the Cisco IOS IP SLAs operation –Example: –R 1#show ip sla statistics –Round Trip Time (RTT) for Index 1 – Latest RTT: 1 milliseconds –Latest operation start time: *03: 55: 56. 835 EST Mon Oct 25 2010 –Latest operation return code: OK –Number of successes: 87 –Number of failures: 24 –Operation time to live: Forever IP SLA operations status: OK = good Over Threshold = exceed threshold < timeout Timeout = over timeout value Duration of operation Successes & Failure icmp packet statistics

“Show” Commands for IP SLA • show ip sla configuration The output will list the supported operations – – – – Example: Operation number R 1#sh ip sla configuration Entry number: 1 Type of operation to perform: icmp-echo Target address/Source address: 212. 23. 1. 1/200. 1. 1. 2 Operation timeout (milliseconds): 500 Schedule: Operation frequency (seconds): 3 Next Scheduled Start Time: Start Time already passed …. . Life (seconds): Forever Threshold (milliseconds): 2 …. Operation duration Threshold (msec) Operation type Source & destination addresses Timeout (msec) Frequency (sec)

“Show” Commands for Object Tracking • show track Display the detail of the tracked objects – – – – – Example: R 1#sh track Track number Track 1 Response Time Reporter 1 reachability Reachability is Up 3 changes, last change 01: 31: 14 Latest operation return code: OK Latest RTT (millisecs) 1 Tracked by: STATIC-IP-ROUTING 0 Type of objects tracked by this track number IP SLA operation number. The object is tracking the reachability of ip sla 1. Reachability or State status - Up or down IP SLA operations status: OK = good Over Threshold = exceed threshold < timeout Timeout = over timeout value

“Show” Commands for Object Tracking • show track brief Display a list of the tracked objects and its status – – – Example: R 1#sh track brief Track Object 1 rtr 1 2 rtr 1 Parameter reachability state Value Last Change Up 01: 47: 32 Down 00: 33 Track Number IP SLA operation that the track is tracking Reachability or State status up/down

“Show” Commands for Static Routing • show ip route track-table To display information about the tracked static table. – Example: – R 1#sh ip route track-table – ip route 0. 0 200. 1. 1. 1 track 1 state is [up] Track Number State of tracked static route - up/down

“Show” Commands for PBR • Show ip access-list [access number] Using the access-list to confirm if the icmp packets are routed through the right path. – – – Example: R 1#sh ip access-lists Extended IP access list 101 10 permit icmp any host 212. 23. 1. 1 (23 matches) Extended IP access list 102 10 permit icmp host 212. 23. 1. 1 host 200. 1. 1. 2 (15 matches)

Troubleshooting Steps Step 1: Ping Test Step 2: IP SLA • Check IP SLA operation status Step 3: Object Tracking • Check tracked object status Step 4: Tracked Static Route/PBR/HSRP • Check routing table • Check HSRP router roles • Check route-map (show ip route-map & show ip policy)

Useful Debugs • • • IP SLA: debug ip sla trace, debug ip sla error Object Tracking: debug track ICMP packet: debug ip icmp, debug ip packet <access-list> HSRP: debug standby event/packets PBR: debug ip policy, debug route-map

Reference • • Introduction to IP SLA http: //www. cisco. com/en/US/tech/tk 920/tsd_technology_support_sub-protocol_home. html Reliable Static Routing Backup Using Object Tracking http: //www. cisco. com/en/US/docs/ios/12_3 x/12_3 xe/feature/guide/dbackupx. html Policy Based Routing (PBR) http: //www. cisco. com/en/US/products/ps 6637/products_ios_protocol_option_home. html PBR Support for Multiple Tracking Options http: //www. cisco. com/en/US/docs/ios/12_3 t 4/feature/guide/gtpbrtrk. html Enhanced Object Tracking http: //www. cisco. com/en/US/docs/ios/ipapp/configuration/guide/ipapp_eot. html Configuring HSRP with Object Tracking http: //www. cisco. com/en/US/docs/ios/ipapp/configuration/guide/ipapp_hsrp. html Configuring GLBP with Object Tracking http: //www. cisco. com/en/US/docs/ios/ipapp/configuration/guide/ipapp_glbp. html Configuring VRRP with Object Tracking http: //www. cisco. com/en/US/docs/ios/ipapp/configuration/guide/ipapp_vrrp. html