[++doc] background and co.

doc/graphviz/arp-ndp.dot

@@ -0,0 +1,25 @@
+digraph G {
+    node [ shape="box"];
+   rankdir="LR";
+
+
+
+    v6host1 [ label="IPv6 only host (fe80::1 and 2001:db8::1)"];
+    v6host2 [ label="IPv6 only host (fe80::2 and 2001:db8::2)"];
+    v4host1 [ label="IPv4 only host (192.0.2.1)"];
+    v4host2 [ label="IPv4 only host (192.0.2.2)"];
+
+    subgraph cluster_v6 {
+
+    v6host1->v6host2 [ label="ICMP6 neighbor solicitation, who has 2001:db8::2? [Multicast]" ];
+    v6host2->v6host1 [ label="ICMP6 Neighbor Advertisement: 2001:db8::2 has 00:00:0a:00:00:42' [Unicast]" ];
+
+    }
+    subgraph cluster_v4 {
+
+    v4host1->v4host2 [ label="ARP who has 192.0.2.2? [Broadcast]" ];
+    v4host2->v4host1 [ label="ARP 192.0.2.2 is at 00:00:0a:00:00:22' [Unicast]" ];
+
+    }
+
+}

doc/graphviz/icmp6ndp.dot

@@ -0,0 +1,13 @@
+digraph G {
+    node [ shape="box"];
+
+
+    ipv6 [ label="IPv6" ]
+    icmp6 [ label="ICMP6" ]
+    icmp6ns [ label="ICMP6 Neigbor Advertisement" ]
+    icmp6nsll [ label="ICMP6 Neigbor Solicitation Link layer option" ]
+    icmp6other [ label="More option fields" ]
+
+    ipv6->icmp6->icmp6ns->icmp6nsll->icmp6other;
+
+}