Date: Tue, 13 Oct 2015 10:10:03 +0200 From: Terje Elde <terje@elde.net> To: Matthew Seaman <matthew@FreeBSD.org> Cc: freebsd-questions@freebsd.org Subject: Re: Are udp packets with non-routeable ip addresses valid on public network? Message-ID: <1D0B2805-EE1F-48E8-A0F6-94B3A93BE175@elde.net> In-Reply-To: <561CAD63.3040103@FreeBSD.org> References: <561BB03D.1060104@gmail.com> <51462673-A972-40A4-A5AF-163834A154CC@elde.net> <561CAD63.3040103@FreeBSD.org>
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--Apple-Mail=_B72C3EF9-802D-44A7-A131-6699EFB9CED6 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset=windows-1252 > On 13 Oct 2015, at 09:06, Matthew Seaman <matthew@FreeBSD.org> wrote: >=20 > Uh... DHCP usually uses just layer-2 (ie. Ethernet) addressing which = is > a useful feature in a protocol designed to specify host IP = addresses... > In those cases where you can't have a DHCP server on the same ethernet > segment, there is a specific default IP address range for a client = host > to fall back to in order to make a layer-3 connection to a DHCP server > -- which is the 169.254.0.0/16 link-local address range. See RFC = 5735. Using my ISP as an example, they=92re operating their DHCP-server on = 10.245.0.1. It=92s actually quite common. As for =93just layer-2 addressing=94, I=92m not sure about your wording, = as there=92s always L3 involved, just broadcast ones. I do get your = point though, and it=92s valid for initial setup, but using direct = unicast between server and client is fine once they=92ve established an = IP. For things like renewals. > If his ISP was using 10.0.0.0/8 addresses for their customer-facing > network segments, I'm pretty sure the OP would have been told about it > and hence not be alarmed at seeing that traffic. I=92ve never seen or heard of an ISP that informs their customers of = this. In my case, it=92s one of Norways largest cable providers. I=92m not saying it=92s probably in this case, just nice to rule out, or = take the cheap =93Don=92t worry about it.=94 if it is the case. Terje --Apple-Mail=_B72C3EF9-802D-44A7-A131-6699EFB9CED6 Content-Transfer-Encoding: 7bit Content-Disposition: attachment; filename=signature.asc Content-Type: application/pgp-signature; name=signature.asc Content-Description: Message signed with OpenPGP using GPGMail -----BEGIN PGP SIGNATURE----- Comment: Public key and proof available here: https://keybase.io/tld iQEcBAEBCgAGBQJWHLxbAAoJEFS925qcwrKGRBwH/01L8yhtcjNirDFTSzfAnjJj 1AycqSEvjvKsb+BXM2HNlLqKeK9FysrOJsRKdMe+qbKURpgXME7sS5id2+u3f+aK SPMIt6cfhxP77pw0ykVkqaCDt1STte+ZhJtqd3NZCp2sl/1Oym2d3diGuqv+ohTv +h4OL72eIOz5Y6683a/qj8dny9ZUiOWMGVgZWuz/7/tzyU0QJg3zI7rG812Cnhd3 1i7McpDPqUCf+qzfAMmdSw8Z/t3pmYAsh/30JIh8feflmwSzqekEOQG/gPLHtJgF TnNF8riF4aOg6CbHwK5HI8tWXv04x68aIzCTpZAdQK1vS31zO4TjBUep8e0nYc8= =kTCZ -----END PGP SIGNATURE----- --Apple-Mail=_B72C3EF9-802D-44A7-A131-6699EFB9CED6--
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