Dear,
I absolutely agree with you. But the comments came from the examples that I have used.
I will make necessary changes with your suggestions.
Accept all only from admin IPs.
Accept from all only 53 and 123 ports.
And I have observed the following... I am also getting a lot of ACK,PSH messages and apparently all the messages gone when I have added a new condition to the rule:
Now the rule is chain input !LAN !DSTNAT. Apparently all that messages are from connections from nat.
Sincerely,
First of all why do you use such a twisted rule??
defconf: drop all not coming from LAN rule in the firewall. Basically it is an input drop !LAN
Much better and clearer to simply say
accept all coming from LAN
drop all else
This leads to the logical next step, which you may have not noticed with the original default (designed for simple flat network).
accept all coming from LAN but only with source address of ADMIN
accept all coming from LAN for ONLY required services, normally DNS and sometimes NTP
drop all else.
Because the whole LAN does not require full access to the router!! (input chain = to the router) better security practice!