diff --git a/ifchd/ifchd.c b/ifchd/ifchd.c
index 7b8808d..7bae147 100644
--- a/ifchd/ifchd.c
+++ b/ifchd/ifchd.c
@@ -374,8 +374,7 @@ static int execute_buffer(struct ifchd_client *cl, char *newbuf)
     strlcat(buf, cl->ibuf, sizeof buf);
     strlcat(buf, newbuf, sizeof buf);
 
-    for (;;) {
-        endp = p;
+    for (endp = p;;p = endp) {
         if (cl->state == STATE_NOTHING) {
             char *colon = strchr(p, ':');
             if (!colon)
@@ -400,6 +399,9 @@ static int execute_buffer(struct ifchd_client *cl, char *newbuf)
             endp = semi + 1;
         }
 
+        if (!strlen(p))
+            continue;
+
         switch (cl->state) {
             case STATE_NOTHING:
                 if (strncmp(p, CMD_INTERFACE, sizeof(CMD_INTERFACE)) == 0)
@@ -506,7 +508,6 @@ static int execute_buffer(struct ifchd_client *cl, char *newbuf)
                 log_line("warning: invalid state in dispatch_work\n");
                 break;
         }
-        p = endp;
     }
     size_t remsize = strlen(endp);
     if (remsize > MAX_BUF - 1)
diff --git a/ifchd/linux.c b/ifchd/linux.c
index 0cace36..69f501d 100644
--- a/ifchd/linux.c
+++ b/ifchd/linux.c
@@ -279,6 +279,9 @@ void perform_mtu(struct ifchd_client *cl, char *str)
         return;
 
     mtu = strtol(str, NULL, 10);
+    // Minimum MTU for physical IPv4 links is 576 octets.
+    if (mtu < 576)
+        return;
     ifrt.ifr_mtu = mtu;
     strlcpy(ifrt.ifr_name, cl->ifnam, IFNAMSIZ);