+ ifindex = if_nametoindex(ifname);
+
+ /* run the pre-up script, if any, and wait for it to finish */
+ ipcp_script(_PATH_IPPREUP, 1);
+
+ /* check if preup script renamed the interface */
+ if (!if_indextoname(ifindex, ifname)) {
+ error("Interface index %d failed to get renamed by a pre-up script", ifindex);
+ ipcp_close(f->unit, "Interface configuration failed");
+ return;
+ }
+