System information
Troubleshooting Banyan VINES 13-291
VIP
Figure 13-3 The VINES Address Selection Process
Dynamic address assignment is not unique in the industry (AppleTalk also uses this process), but it
is certainly not as common as static address assignment. Because addresses are chosen exclusively
by a particular server (whose address is unique as a result of the uniqueness of the hardware key),
there is very little chance of a duplicate address (a potentially devastating problem on Internet
Protocol [IP] and other networks).
In the VINES network scheme, all servers with multiple interfaces are essentially routers. A client
always chooses its own server as a first-hop router, even if another server on the same cable provides
a better route to the ultimate destination. A client can learn about other routers by receiving redirect
messages from its own server. Because clients rely on their servers for first-hop routing, VINES
servers maintain routing tables to help them find remote nodes.
VINES routing tables consist of host/cost pairs, where host corresponds to a network node that can
be reached and cost corresponds to a delay, expressed in milliseconds, to get to that node. RTP helps
VINES servers find neighboring clients, servers, and routers.
Periodically, all clients advertise both their network-layer and their Media Access Control
(MAC)–layer addresses with the equivalent of a hello packet. Hello packets indicate that the client
is still operating and network ready. The servers themselves send routing updates to other servers
periodically. Routing updates alert other routers to changes in node addresses and network topology.
Client Server 1 Server 2
Broadcast
any servers?
1
Client Server 1 Server 2
I’m here I’m here
2
Client Server 1 Server 2
Server 1,
please assign
me an address
3
Client Server 1 Server 2
Your address is
Server 1, Node 8001
4