how to troubleshoot the ping request time out in complex network

[Dr.X]

hi ,

i have a complex network  for  ISP  ,

i just drawed a simple portion of network

im doubting of an internal progblem in my network !!

because i have  ping reuqest time out

Im pinging from PC  station to the router ip 10.160.150.2

note that the timeout must be  less than 1 second , but some pings have 30 ms , i thibk this is an internal congestion problem

i performed two pings test

one for google 8.8.8.8

and the other for 10.160.150.2

here is the results :

C:\Users\PRTG>ping 10.160.150.2 -t

Pinging 10.160.150.2 with 32 bytes of data:

Reply from 10.160.150.2: bytes=32 time<1ms TTL=254

Reply from 10.160.150.2: bytes=32 time<1ms TTL=254

Reply from 10.160.150.2: bytes=32 time<1ms TTL=254

Reply from 10.160.150.2: bytes=32 time<1ms TTL=254

Request timed out.

Reply from 10.160.150.2: bytes=32 time<1ms TTL=254

Reply from 10.160.150.2: bytes=32 time<1ms TTL=254

Reply from 10.160.150.2: bytes=32 time<1ms TTL=254

Reply from 10.160.150.2: bytes=32 time<1ms TTL=254

Reply from 10.160.150.2: bytes=32 time<1ms TTL=254

Reply from 10.160.150.2: bytes=32 time<1ms TTL=254

Reply from 10.160.150.2: bytes=32 time<1ms TTL=254

Reply from 10.160.150.2: bytes=32 time<1ms TTL=254

Reply from 10.160.150.2: bytes=32 time<1ms TTL=254

Reply from 10.160.150.2: bytes=32 time<1ms TTL=254

Reply from 10.160.150.2: bytes=32 time<1ms TTL=254

Reply from 10.160.150.2: bytes=32 time<1ms TTL=254

Reply from 10.160.150.2: bytes=32 time<1ms TTL=254

Reply from 10.160.150.2: bytes=32 time<1ms TTL=254

Reply from 10.160.150.2: bytes=32 time<1ms TTL=254

Reply from 10.160.150.2: bytes=32 time<1ms TTL=254

Reply from 10.160.150.2: bytes=32 time<1ms TTL=254

Reply from 10.160.150.2: bytes=32 time<1ms TTL=254

Reply from 10.160.150.2: bytes=32 time<1ms TTL=254

Reply from 10.160.150.2: bytes=32 time<1ms TTL=254

Reply from 10.160.150.2: bytes=32 time<1ms TTL=254

Reply from 10.160.150.2: bytes=32 time<1ms TTL=254

Reply from 10.160.150.2: bytes=32 time<1ms TTL=254

Reply from 10.160.150.2: bytes=32 time<1ms TTL=254

Reply from 10.160.150.2: bytes=32 time<1ms TTL=254

Reply from 10.160.150.2: bytes=32 time<1ms TTL=254

Reply from 10.160.150.2: bytes=32 time<1ms TTL=254

Reply from 10.160.150.2: bytes=32 time<1ms TTL=254

Request timed out.

Reply from 10.160.150.2: bytes=32 time<1ms TTL=254

Reply from 10.160.150.2: bytes=32 time<1ms TTL=254

Reply from 10.160.150.2: bytes=32 time<1ms TTL=254

Reply from 10.160.150.2: bytes=32 time<1ms TTL=254

Reply from 10.160.150.2: bytes=32 time<1ms TTL=254

Reply from 10.160.150.2: bytes=32 time<1ms TTL=254

Reply from 10.160.150.2: bytes=32 time<1ms TTL=254

Reply from 10.160.150.2: bytes=32 time<1ms TTL=254

Reply from 10.160.150.2: bytes=32 time<1ms TTL=254

Reply from 10.160.150.2: bytes=32 time<1ms TTL=254

Reply from 10.160.150.2: bytes=32 time<1ms TTL=254

Reply from 10.160.150.2: bytes=32 time<1ms TTL=254

Reply from 10.160.150.2: bytes=32 time<1ms TTL=254

Reply from 10.160.150.2: bytes=32 time<1ms TTL=254

Reply from 10.160.150.2: bytes=32 time<1ms TTL=254

Reply from 10.160.150.2: bytes=32 time<1ms TTL=254

Reply from 10.160.150.2: bytes=32 time<1ms TTL=254

Reply from 10.160.150.2: bytes=32 time<1ms TTL=254

Reply from 10.160.150.2: bytes=32 time<1ms TTL=254

Reply from 10.160.150.2: bytes=32 time<1ms TTL=254

Reply from 10.160.150.2: bytes=32 time<1ms TTL=254

Request timed out.

Reply from 10.160.150.2: bytes=32 time=9ms TTL=254

Reply from 10.160.150.2: bytes=32 time<1ms TTL=254

Reply from 10.160.150.2: bytes=32 time<1ms TTL=254

Reply from 10.160.150.2: bytes=32 time<1ms TTL=254

as u see , we have timeout !!!

i want a  briedf tshoot method to know why this timeout in the ping happend

regards

[Raju Sekharan · Accepted solution]

1. 1st we need to check if there is any QOS policy or rate-limiter which is dropping ping packets. Also check if the there is any packet drop on the interfaces in the path

2. 2nd we need to know in which directiion ping drops are happening. you can use an incomign acl or netdr to capture the ping packets reaching CPU of 7600

Steps for netdr

==========

from enable prompt

1. debug netdr capture rx source-ip-address destination-ip-address 10.160.150.2

2. do 100 pings from the PC to 10.160.150.2

3. undebug all on 7600 router

4. show netdr captured-packets

Check if you received all the packets

=============

3. You can use the netdr for tx too to find out if we are replying to all the ping packets

4. If you have multiple links between the router and the switch, testing using one link at a time is another way to isolate if there is any paacket loss in any of the links

Thanks

Raju

[Dr.X]

hi

Raju

sorry for late reply ,

i will try netdr , but im afraid to use it because im on production network and dont want routers to get hanged

is this method safety to apply it ?

regards

[Raju Sekharan]

Netdr is a safe tool. We used to use it on routers running very high cpu too to isolate the high cpu

Thanks

Raju