On 10 September 2026 08:47:01 CEST, Saku Ytti via NANOG <nanog@lists.nanog.org> wrote:
On Thu, 10 Sept 2026 at 07:48, Owen DeLong via NANOG <nanog@lists.nanog.org> wrote:
If you’re going to ugly up the trace route that way, probably better to use Link Local (169.254.x.x) addresses than RFC-1918.
That way, the router (should) report a loopback address instead of the interface address in the trace route. Better to have a routable Loopback reported than an RFC-1918 address in most cases.
Can you tell me some example platform(s) that work like this?
Any platform I've come across, if you want to send ICMP from a loop, you need to define it, and will then not care what IP you have on the interface.
But I do agree that RFC1918 as a link-net on the Internet makes very little sense.
-- ++ytti _______________________________________________ NANOG mailing list https://lists.nanog.org/archives/list/nanog@lists.nanog.org/message/HPOQDCXU... Linux uses 192.0.0.8 by default when an IPv6-addressed-only router that is forwarding IPv4 needs to generate an ICMP packet. This is in some IANA reserved space, and is standardized for some similar function, and I believe is in the process of being standardized for this function too.