diff --git a/ospf6d/ospf6_asbr.c b/ospf6d/ospf6_asbr.c
index b1620d4..6eca142 100644
--- a/ospf6d/ospf6_asbr.c
+++ b/ospf6d/ospf6_asbr.c
@@ -411,7 +411,7 @@
 }
 
 void
-ospf6_asbr_redistribute_add (int type, int ifindex, struct prefix *prefix,
+ospf6_asbr_redistribute_add (int type, ifindex_t ifindex, struct prefix *prefix,
                              u_int nexthop_num, struct in6_addr *nexthop)
 {
   int ret;
@@ -557,7 +557,8 @@
 }
 
 void
-ospf6_asbr_redistribute_remove (int type, int ifindex, struct prefix *prefix)
+ospf6_asbr_redistribute_remove (int type, ifindex_t ifindex,
+                                struct prefix *prefix)
 {
   struct ospf6_route *match;
   struct ospf6_external_info *info = NULL;
diff --git a/ospf6d/ospf6_asbr.h b/ospf6d/ospf6_asbr.h
index 73770cc..f3df90b 100644
--- a/ospf6d/ospf6_asbr.h
+++ b/ospf6d/ospf6_asbr.h
@@ -49,7 +49,7 @@
   struct in6_addr forwarding;
   /* u_int32_t tag; */
 
-  unsigned int ifindex;
+  ifindex_t ifindex;
 };
 
 /* AS-External-LSA */
@@ -79,11 +79,11 @@
 extern void ospf6_asbr_lsentry_remove (struct ospf6_route *asbr_entry);
 
 extern int ospf6_asbr_is_asbr (struct ospf6 *o);
-extern void ospf6_asbr_redistribute_add (int type, int ifindex,
+extern void ospf6_asbr_redistribute_add (int type, ifindex_t ifindex,
                                          struct prefix *prefix,
                                          u_int nexthop_num,
                                          struct in6_addr *nexthop);
-extern void ospf6_asbr_redistribute_remove (int type, int ifindex,
+extern void ospf6_asbr_redistribute_remove (int type, ifindex_t ifindex,
                                             struct prefix *prefix);
 
 extern int ospf6_redistribute_config_write (struct vty *vty);
diff --git a/ospf6d/ospf6_interface.c b/ospf6d/ospf6_interface.c
index c9c9011..26f68ac 100644
--- a/ospf6d/ospf6_interface.c
+++ b/ospf6d/ospf6_interface.c
@@ -59,7 +59,7 @@
 };
 
 struct ospf6_interface *
-ospf6_interface_lookup_by_ifindex (int ifindex)
+ospf6_interface_lookup_by_ifindex (ifindex_t ifindex)
 {
   struct ospf6_interface *oi;
   struct interface *ifp;
diff --git a/ospf6d/ospf6_message.c b/ospf6d/ospf6_message.c
index e71b410..d382f03 100644
--- a/ospf6d/ospf6_message.c
+++ b/ospf6d/ospf6_message.c
@@ -1515,7 +1515,7 @@
   unsigned int len;
   char srcname[64], dstname[64];
   struct in6_addr src, dst;
-  unsigned int ifindex;
+  ifindex_t ifindex;
   struct iovec iovector[2];
   struct ospf6_interface *oi;
   struct ospf6_header *oh;
diff --git a/ospf6d/ospf6_neighbor.h b/ospf6d/ospf6_neighbor.h
index 93ffa28..54b7ffe 100644
--- a/ospf6d/ospf6_neighbor.h
+++ b/ospf6d/ospf6_neighbor.h
@@ -53,7 +53,7 @@
   u_int32_t router_id;
 
   /* Neighbor Interface ID */
-  u_int32_t ifindex;
+  ifindex_t ifindex;
 
   /* Router Priority of this neighbor */
   u_char priority;
diff --git a/ospf6d/ospf6_network.c b/ospf6d/ospf6_network.c
index e0be38b..a773750 100644
--- a/ospf6d/ospf6_network.c
+++ b/ospf6d/ospf6_network.c
@@ -113,7 +113,7 @@
 
 /* ospf6 set socket option */
 void
-ospf6_sso (u_int ifindex, struct in6_addr *group, int option)
+ospf6_sso (ifindex_t ifindex, struct in6_addr *group, int option)
 {
   struct ipv6_mreq mreq6;
   int ret;
@@ -150,7 +150,7 @@
 
 int
 ospf6_sendmsg (struct in6_addr *src, struct in6_addr *dst,
-               unsigned int *ifindex, struct iovec *message)
+               ifindex_t *ifindex, struct iovec *message)
 {
   int retval;
   struct msghdr smsghdr;
@@ -208,7 +208,7 @@
 
 int
 ospf6_recvmsg (struct in6_addr *src, struct in6_addr *dst,
-               unsigned int *ifindex, struct iovec *message)
+               ifindex_t *ifindex, struct iovec *message)
 {
   int retval;
   struct msghdr rmsghdr;
diff --git a/ospf6d/ospf6_network.h b/ospf6d/ospf6_network.h
index 127bf45..f4b74fa 100644
--- a/ospf6d/ospf6_network.h
+++ b/ospf6d/ospf6_network.h
@@ -29,12 +29,12 @@
 extern struct in6_addr alldrouters6;
 
 extern int ospf6_serv_sock (void);
-extern void ospf6_sso (u_int ifindex, struct in6_addr *group, int option);
+extern void ospf6_sso (ifindex_t ifindex, struct in6_addr *group, int option);
 
 extern int ospf6_sendmsg (struct in6_addr *, struct in6_addr *,
-                          unsigned int *, struct iovec *);
+                          ifindex_t *, struct iovec *);
 extern int ospf6_recvmsg (struct in6_addr *, struct in6_addr *,
-                          unsigned int *, struct iovec *);
+                          ifindex_t *, struct iovec *);
 
 #endif /* OSPF6_NETWORK_H */
 
diff --git a/ospf6d/ospf6_route.h b/ospf6d/ospf6_route.h
index 42eb69e..2fb2c1d 100644
--- a/ospf6d/ospf6_route.h
+++ b/ospf6d/ospf6_route.h
@@ -41,7 +41,7 @@
 struct ospf6_nexthop
 {
   /* Interface index */
-  unsigned int ifindex;
+  ifindex_t ifindex;
 
   /* IP address, if any */
   struct in6_addr address;
diff --git a/ospf6d/ospf6_snmp.c b/ospf6d/ospf6_snmp.c
index 307d420..266031e 100644
--- a/ospf6d/ospf6_snmp.c
+++ b/ospf6d/ospf6_snmp.c
@@ -623,7 +623,7 @@
                      int exact, size_t *var_len, WriteMethod **write_method)
 {
   struct ospf6_lsa *lsa = NULL;
-  u_int32_t ifindex, area_id, id, instid, adv_router;
+  ifindex_t ifindex, area_id, id, instid, adv_router;
   u_int16_t type;
   int len;
   oid *offset;
@@ -835,7 +835,8 @@
 ospfv3IfEntry (struct variable *v, oid *name, size_t *length,
 		int exact, size_t *var_len, WriteMethod **write_method)
 {
-  unsigned int ifindex, instid;
+  ifindex_t ifindex = 0;
+  unsigned int instid = 0;
   struct ospf6_interface *oi = NULL;
   struct ospf6_lsa *lsa = NULL;
   struct interface      *iif;
@@ -849,8 +850,6 @@
       == MATCH_FAILED)
     return NULL;
 
-  ifindex = instid = 0;
-
   /* Check OSPFv3 instance. */
   if (ospf6 == NULL)
     return NULL;
@@ -988,7 +987,8 @@
 ospfv3NbrEntry (struct variable *v, oid *name, size_t *length,
 		int exact, size_t *var_len, WriteMethod **write_method)
 {
-  unsigned int ifindex, instid, rtrid;
+  ifindex_t ifindex = 0;
+  unsigned int instid, rtrid;
   struct ospf6_interface *oi = NULL;
   struct ospf6_neighbor  *on = NULL;
   struct interface      *iif;
@@ -1001,7 +1001,7 @@
       == MATCH_FAILED)
     return NULL;
 
-  ifindex = instid = rtrid = 0;
+  instid = rtrid = 0;
 
   /* Check OSPFv3 instance. */
   if (ospf6 == NULL)
diff --git a/ospf6d/ospf6_spf.c b/ospf6d/ospf6_spf.c
index 88e1285..858398e 100644
--- a/ospf6d/ospf6_spf.c
+++ b/ospf6d/ospf6_spf.c
@@ -225,7 +225,8 @@
 ospf6_nexthop_calc (struct ospf6_vertex *w, struct ospf6_vertex *v,
                     caddr_t lsdesc)
 {
-  int i, ifindex;
+  int i;
+  ifindex_t ifindex;
   struct ospf6_interface *oi;
   u_int16_t type;
   u_int32_t adv_router;
@@ -235,7 +236,10 @@
 
   assert (VERTEX_IS_TYPE (ROUTER, w));
   ifindex = (VERTEX_IS_TYPE (NETWORK, v) ? v->nexthop[0].ifindex :
-             ROUTER_LSDESC_GET_IFID (lsdesc));
+             /* v is the local router & the interface_id is a local ifindex */
+             (ifindex_t) ROUTER_LSDESC_GET_IFID (lsdesc));
+  assert (ifindex >= 0);
+  
   oi = ospf6_interface_lookup_by_ifindex (ifindex);
   if (oi == NULL)
     {
diff --git a/ospf6d/ospf6_zebra.c b/ospf6d/ospf6_zebra.c
index d37e508..30b6fc6 100644
--- a/ospf6d/ospf6_zebra.c
+++ b/ospf6d/ospf6_zebra.c
@@ -368,7 +368,7 @@
   char buf[64];
   int nhcount;
   struct in6_addr **nexthops;
-  unsigned int *ifindexes;
+  ifindex_t *ifindexes;
   int i, ret = 0;
   struct prefix_ipv6 *dest;