diff --git a/ip/ipnetns.c b/ip/ipnetns.c
index 03879b49..86b1a36b 100644
--- a/ip/ipnetns.c
+++ b/ip/ipnetns.c
@@ -28,6 +28,7 @@ static int usage(void)
 {
 	fprintf(stderr, "Usage: ip netns list\n");
 	fprintf(stderr, "       ip netns add NAME\n");
+	fprintf(stderr, "       ip netns attach NAME PID\n");
 	fprintf(stderr, "       ip netns set NAME NETNSID\n");
 	fprintf(stderr, "       ip [-all] netns delete [NAME]\n");
 	fprintf(stderr, "       ip netns identify [PID]\n");
@@ -811,6 +812,86 @@ static int netns_monitor(int argc, char **argv)
 	return 0;
 }
 
+static int netns_attach(int argc, char **argv)
+{
+	/* This function bind mounts an existing network namespace to a
+	 * well known location in the filesystem based on the name provided.
+	 * If everything succeeds, the result is the same as netns_add.
+	 *
+	 * The mount namespace is created so that any necessary
+	 * userspace tweaks like remounting /sys, or bind mounting
+	 * a new /etc/resolv.conf can be shared between users.
+	 */
+	char netns_path[PATH_MAX], proc_path[PATH_MAX];
+	const char *name;
+	int fd;
+	pid_t pid;
+	int made_netns_run_dir_mount = 0;
+
+	if (argc < 2) {
+		fprintf(stderr, "No netns name and PID specified\n");
+		return -1;
+	}
+	name = argv[0];
+
+	if (get_s32(&pid, argv[1], 0) || !pid) {
+		fprintf(stderr, "Invalid PID: %s\n", argv[1]);
+		return -1;
+	}
+
+	snprintf(netns_path, sizeof(netns_path), "%s/%s", NETNS_RUN_DIR, name);
+
+	if (create_netns_dir())
+		return -1;
+
+	/* Make it possible for network namespace mounts to propagate between
+	 * mount namespaces.  This makes it likely that a unmounting a network
+	 * namespace file in one namespace will unmount the network namespace
+	 * file in all namespaces allowing the network namespace to be freed
+	 * sooner.
+	 */
+	while (mount("", NETNS_RUN_DIR, "none", MS_SHARED | MS_REC, NULL)) {
+		/* Fail unless we need to make the mount point */
+		if (errno != EINVAL || made_netns_run_dir_mount) {
+			fprintf(stderr, "mount --make-shared %s failed: %s\n",
+				NETNS_RUN_DIR, strerror(errno));
+			return -1;
+		}
+
+		/* Upgrade NETNS_RUN_DIR to a mount point */
+		if (mount(NETNS_RUN_DIR, NETNS_RUN_DIR, "none", MS_BIND | MS_REC, NULL)) {
+			fprintf(stderr, "mount --bind %s %s failed: %s\n",
+				NETNS_RUN_DIR, NETNS_RUN_DIR, strerror(errno));
+			return -1;
+		}
+		made_netns_run_dir_mount = 1;
+	}
+
+	/* Create the filesystem state */
+	fd = open(netns_path, O_RDONLY|O_CREAT|O_EXCL, 0);
+	if (fd < 0) {
+		fprintf(stderr, "Cannot create namespace file \"%s\": %s\n",
+			netns_path, strerror(errno));
+		return -1;
+	}
+	close(fd);
+
+	snprintf(proc_path, sizeof(proc_path), "/proc/%d/ns/net", pid);
+
+	/* Bind the netns last so I can watch for it */
+	if (mount(proc_path, netns_path, "none", MS_BIND, NULL) < 0) {
+		fprintf(stderr, "Bind %s -> %s failed: %s\n",
+			proc_path, netns_path, strerror(errno));
+		goto out_delete;
+	}
+	return 0;
+out_delete:
+	if (unlink(netns_path) < 0)
+		fprintf(stderr, "Cannot remove namespace file \"%s\": %s\n",
+			netns_path, strerror(errno));
+	return -1;
+}
+
 static int invalid_name(const char *name)
 {
 	return !*name || strlen(name) > NAME_MAX ||
@@ -866,6 +947,9 @@ int do_netns(int argc, char **argv)
 	if (matches(*argv, "monitor") == 0)
 		return netns_monitor(argc-1, argv+1);
 
+	if (matches(*argv, "attach") == 0)
+		return netns_attach(argc-1, argv+1);
+
 	fprintf(stderr, "Command \"%s\" is unknown, try \"ip netns help\".\n", *argv);
 	exit(-1);
 }
diff --git a/man/man8/ip-netns.8 b/man/man8/ip-netns.8
index d539f18b..39a10e76 100644
--- a/man/man8/ip-netns.8
+++ b/man/man8/ip-netns.8
@@ -19,6 +19,10 @@ ip-netns \- process network namespace management
 .B ip netns add
 .I NETNSNAME
 
+.ti -8
+.B ip netns attach
+.I NETNSNAME PID
+
 .ti -8
 .B ip [-all] netns del
 .RI "[ " NETNSNAME " ]"
@@ -89,6 +93,12 @@ This command displays all of the network namespaces in /var/run/netns
 If NAME is available in /var/run/netns/ this command creates a new
 network namespace and assigns NAME.
 
+.TP
+.B ip netns attach NAME PID - create a new named network namespace
+.sp
+If NAME is available in /var/run/netns/ this command attaches the network
+namespace of the process PID to NAME as if it were created with ip netns.
+
 .TP
 .B ip [-all] netns delete [ NAME ] - delete the name of a network namespace(s)
 .sp
