diff -u -p busybox-1.00/networking/libiproute/ll_map.c-old busybox-1.00/networking/libiproute/ll_map.c
--- busybox-1.00/networking/libiproute/ll_map.c-old	2005-06-02 12:00:30.000000000 -0700
+++ busybox-1.00/networking/libiproute/ll_map.c	2005-06-02 11:59:12.000000000 -0700
@@ -17,6 +17,10 @@
 
 #include "libnetlink.h"
 
+#include <sys/socket.h>	/* socket() */
+#include <net/if.h>	/* struct ifreq and co. */
+#include <sys/ioctl.h>	/* ioctl() & SIOCGIFINDEX */
+
 struct idxmap
 {
 	struct idxmap * next;
@@ -131,6 +135,7 @@ int ll_name_to_index(char *name)
 	static char ncache[16];
 	static int icache;
 	struct idxmap *im;
+	int sock_fd;
 	int i;
 
 	if (name == NULL)
@@ -146,6 +151,28 @@ int ll_name_to_index(char *name)
 			}
 		}
 	}
+	/* We have not found the interface in our cache, but the kernel
+	 * may still know about it. One reason is that we may be using
+	 * module on-demand loading, which means that the kernel will
+	 * load the module and make the interface exist only when
+	 * we explicitely request it (check for dev_load() in net/core/dev.c).
+	 * I can think of other similar scenario, but they are less common...
+	 * Jean II */
+	sock_fd = socket(AF_INET, SOCK_DGRAM, 0);
+	if(sock_fd) {
+		struct ifreq ifr;
+		int ret;
+		strncpy(ifr.ifr_name, name, IFNAMSIZ);
+		ifr.ifr_ifindex = -1;
+		ret = ioctl(sock_fd, SIOCGIFINDEX, &ifr);
+		close(sock_fd);
+		if(ret >= 0)
+			/* In theory, we should redump the interface list
+			 * to update our cache, this is left as an exercise
+			 * to the reader... Jean II */
+			return ifr.ifr_ifindex;
+	}
+	
 	return 0;
 }