How does it work about NixOS's default iptables?

I installed NixOS on my personal Computer.
Its a 19.09.1977.1dadefec574 (Loris).

then, I realized that NixOS’s default iptables is a little weird.

Chain nixos-fw (1 references)
target     prot opt source               destination
nixos-fw-accept  all  --  
nixos-fw-accept  all  --              ctstate RELATED,ESTABLISHED
nixos-fw-accept  tcp  --              tcp dpt:22
nixos-fw-accept  icmp --              icmptype 8
nixos-fw-log-refuse  all  --  

Chain nixos-fw-accept (4 references)
target     prot opt source               destination
ACCEPT     all  --  

Above is default iptables.

The Chain of nixos-fw-accept allows every traffics, but actually, It did not allow any traffics except ssh and icmp.

Could you tell me the reason why I could not use any traffics except ssh and icmp…

You didn’t show all details of the rules. Try
# iptables -vnL
The first line in nixos-fw is probably limited to the interface lo.


Thank you very much !!
I did not notice at all.

Chain nixos-fw (1 references)
 pkts bytes target     prot opt in     out     source               destination
 466K  134M nixos-fw-accept  all  --  lo     *  

you are right !!