Date: Mon, 15 Sep 2003 12:17:01 +0200 From: Hasse Hansson <webmaster@swedehost.com> To: Roman Neuhauser <neuhauser@bellavista.cz> Cc: FreeBSD Questions <freebsd-questions@freebsd.org> Subject: Re: Need help to interp kernel log message. Message-ID: <200309151217.02016.webmaster@swedehost.com> In-Reply-To: <20030913012430.GE1498@freepuppy.bellavista.cz> References: <200309120537.17416.webmaster@swedehost.com> <20030913012430.GE1498@freepuppy.bellavista.cz>
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On Saturday 13 September 2003 03.24, Roman Neuhauser wrote:
> # webmaster@swedehost.com / 2003-09-12 05:37:17 +0200:
> > I 've got a message in my logfiles that I don't understand.
> > The ip-addresses are none that I'm to my knowing are associated
> > with. Wonder what it is or if it's anything to worry about.
> >
> > odin.swedehost.com kernel log messages:
> > > icmp redirect from 65.104.98.146: 204.152.184.189 =>
> > > 65.104.98.145
> >
> > Checking up on the above Ip-addresses don't ring any bells ider.
>
> Looks like your machine was sending traffic to 204.152.184.189,
> and an intermediate host at 65.104.98.146 sent an ICMP redirect
> message telling it to send them to 65.104.98.145 instead. See RFC
> 792.
>
> As for security concerns: any packet might have the source
> address spoofed, and obeying ICMP type 5 messages in a hostile
> environment (like the internet) means you're giving your network
> traffic out for public consumption.
Thx for your answer.
In my rc.conf file, I do have
icmp_drop_redirect="YES"
icmp_log_redirect="YES"
but I guess that's not enough.
Probably have to block in my firewall.
After reading your reply, I've done some more digging, and this is what
I've found.
<snip>
5 Redirect [RFC792]
Codes
0 Redirect Datagram for the Network (or subnet)
1 Redirect Datagram for the Host
2 Redirect Datagram for the Type of Service and Network
3 Redirect Datagram for the Type of Service and Host
</snip>
/Geir.
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