Describe the problem of unbound names in multicast navigation. What is implied by the installation of a server for responding to lookups of unbound names?

Question

What will be an ideal response?

Answer 1

In multicast navigation, a client multicasts a name to a group of servers for resolution. If a server can resolve
the name, it replies to the client. To minimise messages, a server that cannot resolve the name does not respond.
However if no server can resolve the name – the name is unbound – then the client will be greeted with silence.
It must re-send the request, in case it was dropped. The client cannot distinguish this case from that of the
failure of a server that can resolve the name.
A solution to this problem is to install a member of the group which keeps track of all bound names, but does
not need to store the corresponding attributes. When a request is multicast to the group, this server looks for
the name in its list of bound names. If the name appears in the list, it does nothing. If, however, the name is
not in its list, then it sends a ‘name unbound’ response message to the client. The implication is that this special
server must be notified whenever a client binds or unbinds a name, increasing the overheads for these
operations.