Solved: IP SLA path echo analysis

Chamindaw_2 · ‎05-25-2011

Hi All,

I'm just trying to analyse ICMP path echo between two Cisco devices which are 4 hops apart from ech other.

Here is my configuration.

ip sla monitor 150
type pathEcho protocol ipIcmpEcho 192.168.128.12 source-ipaddr 192.168.133.253
verify-data
frequency 30
ip sla monitor schedule 150 life 600 start-time now

Router#sh ip sla monitor configuration 150

IP SLA Monitor, Infrastructure Engine-II.
Entry number: 150
Owner:
Tag:
Type of operation to perform: pathEcho
Target address: 192.168.128.12
Source address: 192.168.133.253
Request size (ARR data portion): 28
Operation timeout (milliseconds): 5000
Type Of Service parameters: 0xB8
Verify data: Yes
Loose Source Routing: Disabled
Vrf Name:
LSR Path:
Operation frequency (seconds): 30
Next Scheduled Start Time: Start Time already passed
Group Scheduled : FALSE
Life (seconds): 600
Entry Ageout (seconds): never
Recurring (Starting Everyday): FALSE
Status of entry (SNMP RowStatus): Active
Threshold (milliseconds): 5000
Number of statistic hours kept: 2
Number of statistic paths kept: 5
Number of statistic hops kept: 16
Number of statistic distribution buckets kept: 1
Statistic distribution interval (milliseconds): 20
Number of history Lives kept: 0
Number of history Buckets kept: 15
Number of history Samples kept: 16
History Filter Type: None

below is "show" statistics;

Router#sh ip sla monitor statistics details
Round trip time (RTT) Index 150
Latest RTT: Unknown
Latest operation return code: Unknown
Latest operation start time: Unknown
Over thresholds occurred: FALSE
Operation time to live: 580 sec
Operational state of entry: Active
Last time this entry was reset: Never

This doesn't give me any sence of "per hop" delay across the parth between two devices. According to the attached Cisco document, I should be able to get hop-by-hop delay between the devices.

Can any one of you all explane me "how to analyse the per hop delay" with this operation.

Thank You,

Chaminda

Fabrizio Pedracini · ‎06-01-2011

Hi Chaminda,

ip sla 300 seems to work fine. Source and destination are different though.

ip sla 150 on the other end does not seem to work. Is it configured on the same router ?

For sla 150, have you tried the following:

- traceroute 192.168.128.12 source 192.168.133.253

- if you get all the hops' ip addresses correctly do a ping to each of them sourcing the traffic from 192.168.133.253

- have you tried also to reconfigure the command to schedule ip sla 150 ?

To get the stat on each node I suggest to try 'sh ip sla monitor stat aggregated detail'

thanks,

Fabrizio

View solution in original post

Fabrizio Pedracini · ‎06-01-2011

Hi Chaminda,

looks like your ip sla 150 does not work correctly.

> Latest operation return code: Unknown
> Latest operation start time: Unknown

You should see return code "OK" and then a timestamp telling when the task was performed last time.

do you have icmp reachability from source to destination?

can you try to remove the 'ip sla schedule' command and configure it again?

Once it works, you can see hop-by-hop details with 'show ip sla (monitor) stat aggregate 150 det'

hope this helps,

Fabrizio

Chamindaw_2 · ‎06-01-2011

Hi Fabrizio,

Thanks for your reply. As you said I also noticed same and I did another testing with separate probe.

Below given the full details.

Here is my test setup, configurations and “show” outputs.

Test setup;

Router-1#sh version

Cisco IOS Software, 1841 Software (C1841-ADVIPSERVICESK9-M), Version 12.4(18), RELEASE SOFTWARE (fc1)

Technical Support: http://www.cisco.com/techsupport

Compiled Fri 30-Nov-07 14:58 by prod_rel_team

ROM: System Bootstrap, Version 12.4(13r)T, RELEASE SOFTWARE (fc1)

Suntel-FO_CIM uptime is 8 weeks, 20 hours, 3 minutes

System returned to ROM by power-on

System restarted at 22:36:23 ZP6 Thu Mar 31 2011

System image file is "flash:c1841-advipservicesk9-mz.124-18.bin"

--out put omitted--

Cisco 1841 (revision 7.0) with 115712K/15360K bytes of memory.

Processor board ID FHK122128LG

2 FastEthernet interfaces

2 Serial(sync/async) interfaces

1 Virtual Private Network (VPN) Module

DRAM configuration is 64 bits wide with parity disabled.

191K bytes of NVRAM.

31488K bytes of ATA CompactFlash (Read/Write)

Configuration register is 0x2102

#######################################

ip sla monitor 300

type pathEcho protocol ipIcmpEcho 192.168.160.1 source-ipaddr 192.168.136.1

verify-data

frequency 30

ip sla monitor schedule 300 life 900 start-time now

#################################################

Router-1#sh ip sla monitor configuration

SA Agent, Infrastructure Engine-II

Entry number: 300

Owner:

Tag:

Type of operation to perform: pathEcho

Target address: 192.168.160.1

Source address: 192.168.136.1

Request size (ARR data portion): 28

Operation timeout (milliseconds): 5000

Type Of Service parameters: 0x0

Verify data: Yes

Loose Source Routing: Disabled

Vrf Name:

LSR Path:

Operation frequency (seconds): 30

Next Scheduled Start Time: Start Time already passed

Group Scheduled : FALSE

Life (seconds): 900

Entry Ageout (seconds): never

Recurring (Starting Everyday): FALSE

Status of entry (SNMP RowStatus): Active

Threshold (milliseconds): 5000

Number of statistic hours kept: 2

Number of statistic paths kept: 5

Number of statistic hops kept: 16

Number of statistic distribution buckets kept: 1

Statistic distribution interval (milliseconds): 20

Number of history Lives kept: 0

Number of history Buckets kept: 15

Number of history Samples kept: 16

History Filter Type: None

#####################################

Router-1#sh ip sla monitor statistics 300

Round trip time (RTT) Index 300

Latest RTT: 89 ms

Latest operation start time: 18:31:11.089 ZP6 Fri May 27 2011

Latest operation return code: OK

Operation time to live: 810 sec

Router-1#sh ip sla monitor statistics 300 details

Round trip time (RTT) Index 300

Latest RTT: 14 ms

Latest operation start time: 18:31:41.089 ZP6 Fri May 27 2011

Latest operation return code: OK

Over thresholds occurred: FALSE

Operation time to live: 806 sec

Operational state of entry: Active

Last time this entry was reset: Never

##################################

Router-1#sh ip sla monitor operational-state

Entry number: 300

Modification time: 18:30:11.085 ZP6 Fri May 27 2011

Number of Octets Used by this Entry: 53816

Number of operations attempted: 5

Number of operations skipped: 0

Current seconds left in Life: 776

Operational state of entry: Active

Last time this entry was reset: Never

Connection loss occurred: FALSE

Timeout occurred: FALSE

Over thresholds occurred: FALSE

Latest RTT (milliseconds): 11

Latest operation start time: 18:32:11.089 ZP6 Fri May 27 2011

Latest operation return code: OK

#######################################

Router-1#sh ip sla monitor collection-statistics 300

Entry number: 300

Start Time Index: 18:30:11.197 ZP6 Fri May 27 2011

Path Index: 1

Hop in Path Index: 1

Number of successful operations: 5

Number of operations over threshold: 0

Number of failed operations due to a Disconnect: 0

Number of failed operations due to a Timeout: 0

Number of failed operations due to a Busy: 0

Number of failed operations due to a No Connection: 0

Number of failed operations due to an Internal Error: 0

Number of failed operations due to a Sequence Error: 0

Number of failed operations due to a Verify Error: 0

Target Address 200.100.40.1

##############################

Router-1#ping 192.168.160.1 source 192.168.136.1

Type escape sequence to abort.

Sending 5, 100-byte ICMP Echos to 192.168.160.1, timeout is 2 seconds:

Packet sent with a source address of 192.168.136.1

!!!!!

Success rate is 100 percent (5/5), round-trip min/avg/max = 4/8/28 ms

#################################

Router-1#traceroute 192.168.160.1 source 192.168.136.1

Type escape sequence to abort.

Tracing the route to 192.168.160.1

1 200.100.40.1 8 msec 0 msec 4 msec

2 10.13.64.26 12 msec 24 msec *

Anything you can comment on this?

Thank You,

Chaminda.

Fabrizio Pedracini · ‎06-01-2011

Hi Chaminda,

ip sla 300 seems to work fine. Source and destination are different though.

ip sla 150 on the other end does not seem to work. Is it configured on the same router ?

For sla 150, have you tried the following:

- traceroute 192.168.128.12 source 192.168.133.253

- if you get all the hops' ip addresses correctly do a ping to each of them sourcing the traffic from 192.168.133.253

- have you tried also to reconfigure the command to schedule ip sla 150 ?

To get the stat on each node I suggest to try 'sh ip sla monitor stat aggregated detail'

thanks,

Fabrizio

Chamindaw_2 · ‎06-01-2011

Hi Fabrizio,

Many thanks for your continuous support.

I removed configurations related to IP SLA 150 since there was a firewall blocking inbetween the path and configured IP SLA 300 instead.

It seems IP SLA 300 probe is working fine. In my router I'm using IOS version 12.4(18) and i dont get the command you suggested; 'sh ip sla monitor stat aggregated detail'

Let me ckeck if my IOS supports this command.

.

Seems this command support from 12.4T train according to the Cisco command lookup tool and my IOS doesn't support.

BTW what is the similer command for older IOS versions? I couldn't find any info on this......

Thank you,

CHaminda.

Chamindaw_2 · ‎06-05-2011

Hi Fabrizio,

'sh ip sla monitor stat aggregated detail' command works with 12.4T train and lator IOS codes only. I setup a lab and tested it.

This command gives hop-by-hop detals as I was looking for.

Thank You very juch for your time and support extended.

Thank You again,

Chaminda