+{
+ struct ifreq ifr;
+
+ memset(&ifr, 0, sizeof(ifr));
+ strlcpy(ifr.ifr_name, ifname, sizeof(ifr.ifr_name));
+ ifr.ifr_metric = link_mtu;
+ if (ioctl(sockfd, SIOCSIFMTU, &ifr) < 0) {
+ error("Couldn't set IP MTU: %m");
+ }
+}
+
+/*
+ * tty_send_config - configure the transmit characteristics of
+ * the ppp interface.
+ */
+void
+tty_send_config(mtu, asyncmap, pcomp, accomp)
+ int mtu;