This routine doesn't appear to be used anymore.

Index: sys/net/pipex.c
===================================================================
RCS file: /OpenBSD/src/sys/net/pipex.c,v
diff -u -p -u -p -r1.164 pipex.c
--- sys/net/pipex.c	17 Jul 2026 18:51:29 -0000	1.164
+++ sys/net/pipex.c	20 Sep 2026 16:47:44 -0000
@@ -1708,21 +1708,6 @@ pipex_pptp_userland_lookup_session_ipv4(
 	return pipex_pptp_userland_lookup_session(m0, sintosa(&sin));
 }
 
-#ifdef INET6
-struct pipex_session *
-pipex_pptp_userland_lookup_session_ipv6(struct mbuf *m0, struct in6_addr dst)
-{
-	struct sockaddr_in6 sin6;
-
-	memset(&sin6, 0, sizeof(sin6));
-	sin6.sin6_len = sizeof(sin6);
-	sin6.sin6_family = AF_INET6;
-	in6_recoverscope(&sin6, &dst);
-
-	return pipex_pptp_userland_lookup_session(m0, sin6tosa(&sin6));
-}
-#endif
-
 struct pipex_session *
 pipex_pptp_userland_lookup_session(struct mbuf *m0, struct sockaddr *sa)
 {
Index: sys/net/pipex.h
===================================================================
RCS file: /OpenBSD/src/sys/net/pipex.h,v
diff -u -p -u -p -r1.35 pipex.h
--- sys/net/pipex.h	2 Mar 2025 21:28:32 -0000	1.35
+++ sys/net/pipex.h	20 Sep 2026 16:47:44 -0000
@@ -181,8 +181,6 @@ struct mbuf		*pipex_pptp_input(struct mb
 			    struct pipex_session *, struct netstack *);
 struct pipex_session	*pipex_pptp_userland_lookup_session_ipv4(struct mbuf *,
 			    struct in_addr);
-struct pipex_session	*pipex_pptp_userland_lookup_session_ipv6(struct mbuf *,
-			    struct in6_addr);
 struct pipex_session	*pipex_l2tp_userland_lookup_session(struct mbuf *,
 			    struct sockaddr *);
 struct mbuf		*pipex_pptp_userland_output(struct mbuf *,