This happens unintentionally quite a bit with misconfigured NAT. You will see RFC 1918 source addresses in packets from time to time. I can't speak to the application or value of this, but I have seen this and done it accidentally on one occasion.
Jonathan Kalbfeld office: +1 310 317 7933 fax: +1 310 317 7901 home: +1 310 317 7909 mobile: +1 310 227 1662 ThoughtWave Technologies, Inc. Studio City, CA 91604 https://thoughtwave.com View our network at https://bgp.he.net/AS54380 +1 844 42-LINUX > > On Aug 19, 2025 at 9:34 AM, Sriram, Kotikalapudi (Fed) via NANOG > <[email protected]> wrote: > > > Question: Can a prefix be never routed on the Internet but used only one-way > for source address in IP packets? > > That is. a user owns an IP prefix. They never advertise a route to it in BGP > on the Internet. But they use the prefix solely for source address in IP > traffic from a source to a destination (sink). In this set up, the > destination server obviously cannot/doesn't return any acknowledgements etc. > to the source. Anyone aware if there is any such known application in use on > the Internet - even if it is rare? Thanks. > > Sriram > _______________________________________________ > NANOG mailing list > https://lists.nanog.org/archives/list/[email protected]/message/MSEGDFSZ75EMKVD2FWPFSJBOB24X5GQR/ > _______________________________________________ NANOG mailing list https://lists.nanog.org/archives/list/[email protected]/message/POV2RZVCP3NZUR7O4WEUA3WKVFRMIKK7/
