Date: Sat, 10 Jun 2000 13:58:43 -0700 (PDT) From: Matthew Dillon <dillon@apollo.backplane.com> To: sthaug@nethelp.no Cc: ghormann@alumni.indiana.edu, vdrifter@ocis.ocis.net, security@FreeBSD.ORG Subject: Re: Setting up simple firewall with ipfw Message-ID: <200006102058.NAA23380@apollo.backplane.com> References: <200006101904.MAA22680@apollo.backplane.com> <89461.960668356@verdi.nethelp.no>
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:> You also need to allow ICMP messages through, or TCP will not be
:> able to do path-mtu-discovery. I usually let pings through as well.
:>
:> add ..... allow icmp from any to any icmptypes 0,3,5,8,11,12,13,14
:
:I can sort of understand 12 (Parameter Problem), but why on earth do
:you want to allow 13 and 14 (Timestamp/Timestamp Reply)?
:
:Steinar Haug, Nethelp consulting, sthaug@nethelp.no
Well... why not? A host-redirect ICMP is dangerous. A timestamp/reply
ICMP is not.
-Matt
Matthew Dillon
<dillon@backplane.com>
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