diff -ur nagiosplug-trunk/plugins/check_http.c nagiosplug/plugins/check_http.c
--- nagiosplug-trunk/plugins/check_http.c	2008-01-28 16:20:49.000000000 +0100
+++ nagiosplug/plugins/check_http.c	2008-01-28 17:03:51.000000000 +0100
@@ -97,6 +97,7 @@
 char server_port_text[6] = "";
 char server_type[6] = "http";
 char *server_address;
+char *client_address = NULL;
 char *host_name;
 char *server_url;
 char *user_agent;
@@ -188,6 +189,7 @@
     {"ssl", no_argument, 0, 'S'},
     {"post", required_argument, 0, 'P'},
     {"IP-address", required_argument, 0, 'I'},
+    {"bind-address", required_argument, 0, 'B'},
     {"url", required_argument, 0, 'u'},
     {"port", required_argument, 0, 'p'},
     {"authorization", required_argument, 0, 'a'},
@@ -228,7 +230,7 @@
   }
 
   while (1) {
-    c = getopt_long (argc, argv, "Vvh46t:c:w:A:k:H:P:T:I:a:e:p:s:R:r:u:f:C:nlLSm:M:N", longopts, &option);
+    c = getopt_long (argc, argv, "Vvh46t:c:w:A:k:H:P:T:I:B:a:e:p:s:R:r:u:f:C:nlLSm:M:N", longopts, &option);
     if (c == -1 || c == EOF)
       break;
 
@@ -328,6 +330,9 @@
     case 'I': /* Server IP-address */
       server_address = strdup (optarg);
       break;
+    case 'B': /* Bind address */
+      client_address = strdup (optarg);
+      break;
     case 'u': /* URL path */
       server_url = strdup (optarg);
       server_url_length = strlen (server_url);
@@ -732,7 +737,7 @@
   int result = STATE_UNKNOWN;
 
   /* try to connect to the host at the given port number */
-  if (my_tcp_connect (server_address, server_port, &sd) != STATE_OK)
+  if (my_tcp_bind_connect (server_address, server_port, &sd, client_address) != STATE_OK)
     die (STATE_CRITICAL, _("HTTP CRITICAL - Unable to open TCP socket\n"));
 #ifdef HAVE_SSL
   if (use_ssl == TRUE) {
@@ -1241,6 +1246,9 @@
   printf ("    %s\n", _("Append a port to include it in the header (eg: example.com:5000)"));
   printf (" %s\n", "-I, --IP-address=ADDRESS");
   printf ("    %s\n", _("IP address or name (use numeric address if possible to bypass DNS lookup)."));
+  printf (" %s\n", "-B, --bind-address=ADDRESS");
+  printf ("    %s\n", _("IP address or name on the local machine to be used as the source address"));
+  printf ("    %s\n", _("of the connection."));
   printf (" %s\n", "-p, --port=INTEGER");
   printf (" %s", _("Port number (default: "));
   printf ("%d)\n", HTTP_PORT);
diff -ur nagiosplug-trunk/plugins/netutils.c nagiosplug/plugins/netutils.c
--- nagiosplug-trunk/plugins/netutils.c	2008-01-28 16:20:49.000000000 +0100
+++ nagiosplug/plugins/netutils.c	2008-01-28 17:33:48.000000000 +0100
@@ -163,12 +163,14 @@
 
 /* opens a tcp or udp connection to a remote host or local socket */
 int
-np_net_connect (const char *host_name, int port, int *sd, int proto)
+np_net_connect (const char *host_name, int port, int *sd, int proto, ...)
 {
+	va_list ap;
 	struct addrinfo hints;
-	struct addrinfo *r, *res;
+	struct addrinfo *r, *res, *rb;
 	struct sockaddr_un su;
 	char port_str[6], host[MAX_HOST_ADDRESS_LENGTH];
+	char *bindaddress;
 	size_t len;
 	int socktype, result;
 
@@ -200,6 +202,28 @@
 		}
 
 		r = res;
+
+		va_start(ap, proto);
+		bindaddress = va_arg(ap, char *);
+		va_end(ap);
+		if (bindaddress) {
+			memset (&hints, 0, sizeof (hints));
+			hints.ai_family = AF_UNSPEC;    /* Allow IPv4 or IPv6 */
+			hints.ai_socktype = SOCK_DGRAM; /* Datagram socket */
+			hints.ai_flags = AI_PASSIVE;    /* For wildcard IP address */
+			hints.ai_protocol = 0;          /* Any protocol */
+			hints.ai_canonname = NULL;
+			hints.ai_addr = NULL;
+			hints.ai_next = NULL;
+			
+			result = getaddrinfo (bindaddress, NULL, &hints, &res);
+			if (result != 0) {
+				printf ("%s\n", gai_strerror (result));
+				return STATE_UNKNOWN;
+			}
+			rb = res;
+		}
+
 		while (r) {
 			/* attempt to create a socket */
 			*sd = socket (r->ai_family, socktype, r->ai_protocol);
@@ -210,6 +234,15 @@
 				return STATE_UNKNOWN;
 			}
 
+			/* attempt to bind to source IP */
+			if (bindaddress) {
+				result = bind(*sd, rb->ai_addr, rb->ai_addrlen);
+				if (result != 0) {
+					printf ("%s\n", _("Unable to bind to source address"));
+					return STATE_UNKNOWN;
+				}
+			}
+
 			/* attempt to open a connection */
 			result = connect (*sd, r->ai_addr, r->ai_addrlen);
 
diff -ur nagiosplug-trunk/plugins/netutils.h nagiosplug/plugins/netutils.h
--- nagiosplug-trunk/plugins/netutils.h	2008-01-28 16:20:49.000000000 +0100
+++ nagiosplug/plugins/netutils.h	2008-01-28 17:27:30.000000000 +0100
@@ -64,7 +64,10 @@
 /* my_connect and wrapper macros */
 #define my_tcp_connect(addr, port, s) np_net_connect(addr, port, s, IPPROTO_TCP)
 #define my_udp_connect(addr, port, s) np_net_connect(addr, port, s, IPPROTO_UDP)
-int np_net_connect(const char *address, int port, int *sd, int proto);
+#define my_tcp_bind_connect(addr, port, s, bind_addr) np_net_connect(addr, port, s, IPPROTO_TCP, bind_addr)
+#define my_ucp_bind_connect(addr, port, s, bind_addr) np_net_connect(addr, port, s, IPPROTO_TCP, bind_addr)
+
+int np_net_connect(const char *address, int port, int *sd, int proto, ...);
 
 /* send_request and wrapper macros */
 #define send_tcp_request(s, sbuf, rbuf, rsize) \