Packet Drops - Global DNS - CCR Board - ISP Mumbai

RouterOS General
1

Hello,

Myself Vishal Borhade, Working with one of the ISP at Mumbai. Basically we are facing issue with CCR Board - CCR1036-8G-2S+(tile).
The issue is basically with packet drops towards global DNS (8.8.8.:sunglasses: and this issue is observed only in our network. It is working fine with service provider.

Being an ISP - Two different QoS are configured in the router. One QoS get generated directly from Radius and 2nd added manually for peering sites like Google.
The drops issue get resolved if we disabled the Google IP’s from the address list. No issue observed with Tower servers.

Looking for your support.

Thanks,
Vishal Borhade.
8879885898

2

When you are shaping traffic, of course you are going to face packet loss.
But you can always separate the traffic into different classes, and e.g. give DNS traffic some priority over other traffic.
Mark it with a different packet mark and assign a separate queue with a higher priority in the queue tree.
Make sure you configure limit-at and max-limit on your queues in such a way that the higher priority traffic cannot take
all your bandwidth and starve the lower priority traffic. Otherwise you are an easy victim for DOS attacks.