Avaya Phones drops every third packed when do the extended ping

[raut.pawan]

Hi,

I am seeing Avaya Packed drops every third packed when do the extended ping from router or switch. Anyone has any idea about this behaviours?

Switch#ping 10.10.10.1 repeat 20

Type escape sequence to abort.

Sending 20, 100-byte ICMP Echos to 10.10.10.1, timeout is 2 seconds:

!!.!!.!!.!!.!!.!!.!!

[Ji-Won Park · Accepted solution]

Hi Pawan,

This is normal due to the DOS prevention mechanizm on the CM.

HTH

JP

[raut.pawan]

Hi JP,

You are correct. I have also found same info in Cisco docs.

"This is because the IP phones have been designed to only reply to an echo

every 10ms, in order to withstand Denial of Service (DoS) attacks. DoS

protection is provided by limiting resources for ICMP processing and not

responding to ICMP broadcast pings. A Cisco IOS gateway sends echos more

frequently, so will timeout.This is not the case for a PC since the time

between two echos is greater than 10ms"

[Rakesh Jiwankar]

Hi Pawan,

Yes, you are right

[Step]

Nice, but it confuses when you are in troubleshooting =)