diff --git a/lib/command.c b/lib/command.c
index b3819048e5..4896c8a958 100644
--- a/lib/command.c
+++ b/lib/command.c
@@ -865,29 +865,59 @@ enum match_type
   exact_match 
 };
 
-#define IPV4_ADDR_STR       "0123456789."
-#define IPV4_PREFIX_STR     "0123456789./"
-
-/**
- * Determines whether a string is a valid ipv4 token.
- *
- * @param[in] str the string to match
- * @return exact_match if the string is an exact match, no_match/partly_match
- *         otherwise
- */
 static enum match_type
 cmd_ipv4_match (const char *str)
 {
-  struct sockaddr_in sin_dummy;
+  const char *sp;
+  int dots = 0, nums = 0;
+  char buf[4];
 
   if (str == NULL)
     return partly_match;
 
-  if (strspn (str, IPV4_ADDR_STR) != strlen (str))
-    return no_match;
+  for (;;)
+    {
+      memset (buf, 0, sizeof (buf));
+      sp = str;
+      while (*str != '\0')
+	{
+	  if (*str == '.')
+	    {
+	      if (dots >= 3)
+		return no_match;
 
-  if (inet_pton(AF_INET, str, &sin_dummy.sin_addr) != 1)
-    return no_match;
+	      if (*(str + 1) == '.')
+		return no_match;
+
+	      if (*(str + 1) == '\0')
+		return partly_match;
+
+	      dots++;
+	      break;
+	    }
+	  if (!isdigit ((int) *str))
+	    return no_match;
+
+	  str++;
+	}
+
+      if (str - sp > 3)
+	return no_match;
+
+      strncpy (buf, sp, str - sp);
+      if (atoi (buf) > 255)
+	return no_match;
+
+      nums++;
+
+      if (*str == '\0')
+	break;
+
+      str++;
+    }
+
+  if (nums < 4)
+    return partly_match;
 
   return exact_match;
 }
@@ -895,37 +925,79 @@ cmd_ipv4_match (const char *str)
 static enum match_type
 cmd_ipv4_prefix_match (const char *str)
 {
-  struct sockaddr_in sin_dummy;
-  const char *delim = "/\0";
-  char *dupe, *prefix, *mask, *context, *endptr;
-  int nmask = -1;
+  const char *sp;
+  int dots = 0;
+  char buf[4];
 
   if (str == NULL)
     return partly_match;
 
-  if (strspn (str, IPV4_PREFIX_STR) != strlen (str))
+  for (;;)
+    {
+      memset (buf, 0, sizeof (buf));
+      sp = str;
+      while (*str != '\0' && *str != '/')
+	{
+	  if (*str == '.')
+	    {
+	      if (dots == 3)
+		return no_match;
+
+	      if (*(str + 1) == '.' || *(str + 1) == '/')
+		return no_match;
+
+	      if (*(str + 1) == '\0')
+		return partly_match;
+
+	      dots++;
+	      break;
+	    }
+
+	  if (!isdigit ((int) *str))
+	    return no_match;
+
+	  str++;
+	}
+
+      if (str - sp > 3)
+	return no_match;
+
+      strncpy (buf, sp, str - sp);
+      if (atoi (buf) > 255)
+	return no_match;
+
+      if (dots == 3)
+	{
+	  if (*str == '/')
+	    {
+	      if (*(str + 1) == '\0')
+		return partly_match;
+
+	      str++;
+	      break;
+	    }
+	  else if (*str == '\0')
+	    return partly_match;
+	}
+
+      if (*str == '\0')
+	return partly_match;
+
+      str++;
+    }
+
+  sp = str;
+  while (*str != '\0')
+    {
+      if (!isdigit ((int) *str))
+	return no_match;
+
+      str++;
+    }
+
+  if (atoi (sp) > 32)
     return no_match;
 
-  /* tokenize to address + mask */
-  dupe = XMALLOC(MTYPE_TMP, strlen(str)+1);
-  strncpy(dupe, str, strlen(str)+1);
-  prefix = strtok_r(dupe, delim, &context);
-  mask   = strtok_r(NULL, delim, &context);
-
-  if (!mask)
-    return partly_match;
-
-  /* validate prefix */
-  if (inet_pton(AF_INET, prefix, &sin_dummy.sin_addr) != 1)
-    return no_match;
-
-  /* validate mask */
-  nmask = strtol (mask, &endptr, 10);
-  if (*endptr != '\0' || nmask < 0 || nmask > 32)
-    return no_match;
-
-  XFREE(MTYPE_TMP, dupe);
-
   return exact_match;
 }