diff --git a/proto/babel/babel.c b/proto/babel/babel.c
index d9e3aad2..b4404f45 100644
--- a/proto/babel/babel.c
+++ b/proto/babel/babel.c
@@ -952,6 +952,10 @@ babel_send_update_(struct babel_iface *ifa, btime changed, struct fib *rtable)
     msg.update.next_hop = ((e->n.addr->type == NET_IP4) ?
 			   ifa->next_hop_ip4 : ifa->next_hop_ip6);
 
+    /* Do not send route if next hop is unknown, e.g. no configured IPv4 address */
+    if (ipa_zero(msg.update.next_hop))
+      continue;
+
     babel_enqueue(&msg, ifa);
 
     /* Update feasibility distance for redistributed routes */
@@ -1580,7 +1584,7 @@ babel_add_iface(struct babel_proto *p, struct iface *new, struct babel_iface_con
   ifa->next_hop_ip6 = ipa_nonzero(ic->next_hop_ip6) ? ic->next_hop_ip6 : ifa->addr;
 
   if (ipa_zero(ifa->next_hop_ip4) && p->ip4_channel)
-    log(L_WARN "%s: Cannot find IPv4 next hop addr on %s", p->p.name, new->name);
+    log(L_WARN "%s: Missing IPv4 next hop address for %s", p->p.name, new->name);
 
   init_list(&ifa->neigh_list);
   ifa->hello_seqno = 1;
@@ -1682,7 +1686,7 @@ babel_reconfigure_iface(struct babel_proto *p, struct babel_iface *ifa, struct b
   ifa->next_hop_ip6 = ipa_nonzero(new->next_hop_ip6) ? new->next_hop_ip6 : ifa->addr;
 
   if (ipa_zero(ifa->next_hop_ip4) && p->ip4_channel)
-    log(L_WARN "%s: Cannot find IPv4 next hop addr on %s", p->p.name, ifa->ifname);
+    log(L_WARN "%s: Missing IPv4 next hop address for %s", p->p.name, ifa->ifname);
 
   if (ifa->next_hello > (current_time() + new->hello_interval))
     ifa->next_hello = current_time() + (random() % new->hello_interval);
diff --git a/proto/babel/packets.c b/proto/babel/packets.c
index 59678678..d4ecf649 100644
--- a/proto/babel/packets.c
+++ b/proto/babel/packets.c
@@ -616,7 +616,7 @@ babel_read_update(struct babel_tlv *hdr, union babel_msg *m,
 
     /* Update must have next hop, unless it is retraction */
     if (ipa_zero(state->next_hop_ip4) && (msg->metric != BABEL_INFINITY))
-      return PARSE_ERROR;
+      return PARSE_IGNORE;
 
     /* Merge saved prefix and received prefix parts */
     memcpy(buf, state->def_ip4_prefix, tlv->omitted);
diff --git a/proto/bgp/attrs.c b/proto/bgp/attrs.c
index d65f6334..8ecfaaa2 100644
--- a/proto/bgp/attrs.c
+++ b/proto/bgp/attrs.c
@@ -1109,6 +1109,9 @@ bgp_decode_attrs(struct bgp_parse_state *s, byte *data, uint len)
   if (!BIT32_TEST(s->attrs_seen, BA_AS_PATH))
   { REPORT(NO_MANDATORY, "AS_PATH"); goto withdraw; }
 
+  if (s->ip_reach_len && !BIT32_TEST(s->attrs_seen, BA_NEXT_HOP))
+  { REPORT(NO_MANDATORY, "NEXT_HOP"); goto withdraw; }
+
   /* When receiving attributes from non-AS4-aware BGP speaker, we have to
      reconstruct AS_PATH and AGGREGATOR attributes; RFC 6793 4.2.3 */
   if (!p->as4_session)
diff --git a/proto/ospf/rt.c b/proto/ospf/rt.c
index c0fe218a..b4f9b067 100644
--- a/proto/ospf/rt.c
+++ b/proto/ospf/rt.c
@@ -108,7 +108,7 @@ orta_pref(const orta *nf)
 static int
 orta_prio(const orta *nf)
 {
-  /* RFC 3103 2.5 (6e) priorities */
+  /* RFC 3101 2.5 (6e) priorities */
   u32 opts = nf->options & (ORTA_NSSA | ORTA_PROP);
 
   /* A Type-7 LSA with the P-bit set */
@@ -217,7 +217,7 @@ orta_compare_asbr(const struct ospf_proto *p, const orta *new, const orta *old)
 
 /*
  * Compare a routing table entry with a new one, for AS external routes
- * (RFC 2328 16.4) and NSSA routes (RFC 3103 2.5), Returns integer <, = or >
+ * (RFC 2328 16.4) and NSSA routes (RFC 3101 2.5), Returns integer <, = or >
  * than 0 if the new orta is less, equal or more preferred than the old orta.
  */
 static int
@@ -1078,7 +1078,7 @@ decide_nssa_lsa(struct ospf_proto *p, ort *nf, struct ospf_lsa_ext_local *rt)
   return 1;
 }
 
-/* RFC 3103 3.2 - translating Type-7 LSAs into Type-5 LSAs */
+/* RFC 3101 3.2 - translating Type-7 LSAs into Type-5 LSAs */
 static inline void
 check_nssa_lsa(struct ospf_proto *p, ort *nf)
 {
@@ -1101,12 +1101,12 @@ check_nssa_lsa(struct ospf_proto *p, ort *nf)
     }
   }
 
-  /* RFC 3103 3.2 (3) - originate the aggregated address range */
+  /* RFC 3101 3.2 (3) - originate the aggregated address range */
   if (anet && anet->active && !anet->hidden && oa->translate)
     ospf_originate_ext_lsa(p, NULL, nf, LSA_M_RTCALC, anet->metric,
 			   (anet->metric & LSA_EXT3_EBIT), IPA_NONE, anet->tag, 0);
 
-  /* RFC 3103 3.2 (2) - originate the same network */
+  /* RFC 3101 3.2 (2) - originate the same network */
   else if (decide_nssa_lsa(p, nf, &rt))
     ospf_originate_ext_lsa(p, NULL, nf, LSA_M_RTCALC, rt.metric, rt.ebit, rt.fwaddr, rt.tag, 0);
 }
@@ -1284,7 +1284,7 @@ ospf_rt_abr2(struct ospf_proto *p)
   struct ospf_area *oa;
   struct top_hash_entry *en;
 
-  /* RFC 3103 3.1 - type-7 translator election */
+  /* RFC 3101 3.1 - type-7 translator election */
   struct ospf_area *bb = p->backbone;
   WALK_LIST(oa, p->area_list)
     if (oa_is_nssa(oa))