This is error is occuring at 1 slave site every 15 minutes. The 2
slave
sites cannot communicate with each other, but the master can
communicate
with both. The connection initiation is "both sides" and it is full
mesh.

The error message explination is "A packet was received by a VPN
member
that contained an invalid signature. Either an intruder tried to send
a
packet to the VPN member or the public RSA key of the VPN member is
not
the correct matched RSA key."