Help - flow rules allowing traffic to and from only one peer

[vil]

i’ve been using zerotier with the default flow rules for some time. now i’ve been looking at the tips section and a bunch of posts to try to achieve a configuration on my own but with no luck.

i’m trying to configure the flow rules in a way such that any peer can only communicate to and from a single designated peer. this way peers cannot reach or see each other, only the designated peer.

thanks in advance for any help.

# Allow only IPv4, IPv4 ARP, and IPv6 Ethernet frames.
drop
	not ethertype ipv4
	and not ethertype arp
	#and not ethertype ipv6
;

# This prevents IP spoofing but also 
# blocks manual IP management at the OS level and
# bridging unless special rules to exempt 
# certain hosts or traffic are added before
# this rule.
drop
	not chr ipauth
;

accept
  ztdest abcdef123 # designated peer
;
accept
  ztsrc abcdef123 # designated peer
;