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Date:   Sat, 28 Sep 2019 10:23:58 +0200
From:   Florian Westphal <fw@strlen.de>
To:     Ttttabcd <ttttabcd@protonmail.com>
Cc:     "netfilter-devel@vger.kernel.org" <netfilter-devel@vger.kernel.org>
Subject: Re: Please add Bridge NAT in nftables
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Ttttabcd <ttttabcd@protonmail.com> wrote:
> The NAT function is included in ebtables (although it is very simple, but it is better than nothing), but I did not find the corresponding function in nftables.

You can do stateless mac nat like this:
add rule ... ether saddr set 00:0f:54:0c:11:4

or, with anon map:
add rule ... ether saddr set ip saddr map { 192.168.1.50 :
	00:0f:54:0c:11:4, 192.168.1.100 : 0f:54:0c:11:42 }

or with named map:

add table bridge mynat
add map bridge mynat mymacnatmap "{ type ipv4_addr : ether_addr; flags timeout; }
add rule ... ether saddr set ip saddr map @mynatmap