diff --git a/proto/ospf/packet.c b/proto/ospf/packet.c
index 95f7653c..dd8fa5f0 100644
--- a/proto/ospf/packet.c
+++ b/proto/ospf/packet.c
@@ -140,13 +140,6 @@ ospf_pkt_checkauth(struct ospf_neighbor *n, struct ospf_iface *ifa, struct ospf_
     return 0;
   }
 
-  if (n && (ifa != n->ifa))
-  {
-    OSPF_TRACE(D_PACKETS, "OSPF_auth: received packet from strange interface (%s/%s)",
-      ifa->iface->name, n->ifa->iface->name);
-    return 0;
-  }
-
   switch(ifa->autype)
   {
     case OSPF_AUTH_NONE:
@@ -178,19 +171,13 @@ ospf_pkt_checkauth(struct ospf_neighbor *n, struct ospf_iface *ifa, struct ospf_
         return 0;
       }
 
-      if (ntohs(pkt->length) + OSPF_AUTH_CRYPT_SIZE != size)
+      if (ntohs(pkt->length) + OSPF_AUTH_CRYPT_SIZE > size)
       {
         OSPF_TRACE(D_PACKETS, "OSPF_auth: size mismatch (%d vs %d)",
 	  ntohs(pkt->length) + OSPF_AUTH_CRYPT_SIZE, size);
         return 0;
       }
 
-      if (pkt->u.md5.zero)
-      {
-        OSPF_TRACE(D_PACKETS, "OSPF_auth: \"zero\" area is non-zero");
-        return 0;
-      }
-
       tail = ((void *)pkt) + ntohs(pkt->length);
 
       if (ifa->passwords)