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Date:      Sun, 10 Feb 2013 18:34:14 +0100
From:      James Howlett <jim.howlett@outlook.com>
To:        "khatfield@socllc.net" <khatfield@socllc.net>
Cc:        "freebsd-isp@freebsd.org" <freebsd-isp@freebsd.org>, "freebsd-security@freebsd.org" <freebsd-security@freebsd.org>
Subject:   RE: FreeBSD DDoS protection
Message-ID:  <SNT002-W95E85AB9EE61748F0E5244E50B0@phx.gbl>
In-Reply-To: <935214494.7700.1360514165103@d94655abdbc041fe9f54c404b6b4e89c.nuevasync.com>
References:  <SNT002-W152BF18F12BD59F112A1CBAE5040@phx.gbl>, , <321927899.767139.1360461430134@89b1b4b66ec741cb85480c78b68b8dce.nuevasync.com>, <SNT002-W126C067EAA248C592EBB424E50B0@phx.gbl>, <935214494.7700.1360514165103@d94655abdbc041fe9f54c404b6b4e89c.nuevasync.com>

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Kevin=2C

> That's very helpful to know. So at this time are you doing NAT from the r=
outer or simply passing all traffic and allowing the switch to sort it out?
>

There is no NAT on my router. The setup looks like that:

ISP--switch--FreeBSD-router---switch---firewall (nat=2C etc)

THe switch is basicly one device with some vlans.
My outside conectivity is done by BGP=2C my internal routing is using OSPF =
as an IGMP protocol.
=20
> You can google sflow for FreeBSD. There is an export tool for netflow whi=
ch I have used that exports as sflow via a bridge type conversion. > Works =
incredibly well.


Great=2C I'll look into that. Could You recomend some flow display/analysis=
 software?=20
 =20
> ICMP can be blocked safely but it does need to be specific. For example y=
ou can allow ping and disallow bogus ICMP. You can safely block=2C for exam=
ple=2C UDP port 0 which is commonly attacked.
>

Ok.
=20
> If you do not wish to make it public=2C it's fine. However=2C you can sen=
d me your current pf rules and I can take a look and provide some recommend=
ations.
>=20

My firewall is basic and looks like that:
http://pastebin.com/JJbLxHTS

> Additionally=2C it would be good to know the switch you're using. I'm gue=
ssing since it's sflow that it's Juniper. There are some very useful ACL's =
that can be put in at the switch.

I have both juniper ex2200 and cisco 2960s at hand.=20

>=20
> However=2C if the BSD box is either live locking or crashing then you nee=
d to fix that first.
>=20

The BSD box drops network conectivity - OSPF fails first which causes my ne=
twork to go offline.
The host itself is working - I can access in via iLOM.

> I would state that enabling polling can be done from the command line if =
it's already enabled in the kernel.
>=20
> Enabling polling in itself without tweaking it could likely increase your=
 overall PPS limitations by 70%. So I recommend doing that immediately and =
just placing it on your public facing NIC first.

My ethernet cards use em driver. I can change it to igb cards in few weeks.
Is it save to enable pooling on a production system?

All best=2C
jim

 		 	   		  =



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