As outlined in figure 12.1, PAA consists of three software components. An unconfigured node runs the PAA-client to allocate an unused IP address. The PAA-client communicates with one (or more) PAA-servers running on already configured nodes. These servers communicate with the routing daemons running on their local hosts. All communication between PAA-clients and PAA-servers is done using the link-local address space 192.168.0.0/16 when using IPv4 and fe80:: when using IPv6. DAD flooding is done using the flooding mechanism offered by the routing protocol in addition to link-local traffic.
PAA packets uses the 64-bit header illustrated in figure 12.2, and all traffic is carried using UDP.