1iptables-translate -t filter -A INPUT -m ipcomp --ipcompspi 0x12 -j ACCEPT
2nft add rule ip filter INPUT comp cpi 18 counter accept
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4iptables-translate -t filter -A INPUT -m ipcomp ! --ipcompspi 0x12 -j ACCEPT
5nft add rule ip filter INPUT comp cpi != 18 counter accept
6