About F19 Firewall

Tomasz Torcz tomek at pipebreaker.pl
Sun Sep 15 19:06:09 UTC 2013

On Mon, Sep 16, 2013 at 02:52:07AM +0800, P J P wrote:
>      Hi,
> I upgraded to F19 recently. And I happened to look at the output of iptables(8) today.
>    $ iptables -nL
> It's baffling! It's crazy 4 pages long listing!!

  You seem to have missed this Fedora *18* feature:

> Why
>  are there so many chains? Most are empty. Those which have rules, jump 
> from one chain to another and that jumps to yet another.

  firewall-cmd is supposed to isolate user from all this chains.
> Multicast
>  DNS is allowed in the internal network(chain IN_internal_allow). I 
> guess  IN_internal_allow  is meant for some closed group internal 
> network, not sure.
>     ACCEPT     udp  --            udp dpt:5353 ctstate NEW
> Who uses it?

  That's mDNS, widely used in zeroconf discovery (for example, printers).

Tomasz Torcz                "Funeral in the morning, IDE hacking
xmpp: zdzichubg at chrome.pl    in the afternoon and evening." - Alan Cox

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