decentral vpn with 1 gateway host

[deep_eye]

Hello tinc users,

i have the follow configuration:
1 client/server called master, it is always reachable from internet
(with dyndns)
5 clients, that connects to the master and the other clients (all behind
a router (NAT))

master-hosts-file:
Address = ...
Port = ...
Subnet = ...
Compression = 0
---- key -----

client-hosts-files:
Compression = 0
Subnet = ...
----- key -----

tinc.conf
Name = ....
ConnectTo = master
Device = /dev/net/tun
Mode = switch

i use the master to learn the ip's of the machines behind nat.
the problem is, if the master is for a short time unrechable, than all
clients lose the connection (as long as the master is not reachable).

it is possible to hold the connections between the clients behind a
nat-router without a third node?
if i create a second reachable master and add in the tinc.conf a
additional connectto line, make the clients to both masters a connection
or at first to the first and if it is not reachable then probe/connect
to the second?

greets manuel

PS: sorry for my bad english, i hope it's understandable.