From: Daniel Lakeland <dlakelan@street-artists.org>
To: Netfilter Mailing List <netfilter@vger.kernel.org>
Subject: Re: manipulating the ttl
Date: Sat, 25 Jan 2020 17:17:05 -0800 [thread overview]
Message-ID: <82e00d85-680c-2932-42e2-3b1087bb1013@street-artists.org> (raw)
In-Reply-To: <9c18d561-2033-baa9-718f-29275392acd5@street-artists.org>
On 1/25/20 5:02 PM, Daniel Lakeland wrote:
> As far as I can tell in nftables there's no way to manipulate the TTL
> field in packets, along the lines of iptables -A foo -j TTL --ttl-set
> 2 or the like
>
> This becomes a problem for handling certain multicast scenarios. Is
> this on the horizon?
>
>
>
hmmm in further inspection I see that you can *set* the ttl, something like:
nft add rule inet mytable mychain ip ttl set 2
but I don't see how I could do something like decrement the ttl by 4 or
basically do anything where you'd calculate the TTL as a function of its
current value.
In general calculating simple arithmetic in order to manipulate fields
isn't necessarily obvious in nftables. Any pointers?
next prev parent reply other threads:[~2020-01-26 1:17 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-01-26 1:02 manipulating the ttl Daniel Lakeland
2020-01-26 1:17 ` Daniel Lakeland [this message]
2020-02-13 10:00 ` Duncan Roe
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