pppoe users are getting the ping loss to global dns(8.8.8.8,4.2.2.2) after 10-20 ping the users are getting 1-2 ping packet loss , but this problem is being happening
in only evening time but after few hours this issues is going to be resolved .
Please suggest me what can be the reason for this problem .
Very big range of problems. You need to look at CRC errors to clients port and look at all uplink through distribution switches and core routers protocols flapping. You better do traceroute
There is no FCS error in port when the users are pinging to mikrotik WAN interface IP there is no loss of ping
but when the users are pinging to the Global DNS ip they are getting 2-3 % loss .
Any other destinations affected? Even though it is regularly used as such, 8.8.8.8 is not a “monitoring service”. I had to switch a customer from pinging 8.8.8.8 to 8.8.4.4 for state tracking, because the former stopped responding [but only on one of their WANs].