Poster: Rough Edges for IPv6 in VPNs

Cho, Yejin and Heidemann, John
USC/Information Sciences Institute

citation

Yejin Cho and John Heidemann 2025. Poster: Rough Edges for IPv6 in VPNs. Proceedings of the ACM Internet Measurement Conference (Nov. 2025), 1048–1049. [DOI] [PDF]

abstract

How do VPNs interact with IPv6? Our poster shows that VPNs often leak IPv6 traffic, failing to provide the promised privacy, and VPNs often prefer IPv4, even though IPv6 is available and working. These results use new data from a website for IP identification, coupled with experiments on specific VPN software. We identify the fraction of v6 traffic leaked, and find the root-cause of IPv6 de-preferencing in interactions between address selection in OSes and VPNs.

reference

@inproceedings{Cho25b,
  author = {Cho, Yejin and Heidemann, John},
  title = {Poster: Rough Edges for IPv6 in VPNs},
  booktitle = {Proceedings of the ACM Internet Measurement Conference},
  year = {2025},
  sortdate = {2025-11-27},
  pages = {1048--1049},
  month = nov,
  project = {ant, internetmap, bripod},
  jsubject = {topology_modeling},
  jlocation = {johnh: pafile},
  doi = {https://doi.org/10.1145/3730567.3768612},
  keywords = {ipv6, vpn, leaking private addresess, depreferencing},
  url = {https://ant.isi.edu/%7ejohnh/PAPERS/Cho25b.html},
  pdfurl = {https://ant.isi.edu/%7ejohnh/PAPERS/Cho25b.pdf},
  myorganization = {USC/Information Sciences Institute},
  copyrightholder = {authors}
}