We are running two bitcoin nodes on two different servers with fixed ip addresses in regtest mode. We have forked version 0.11 of bitcoind and decreased the time between blocks to simulate various scenarios.

In the config, we use the following:

regtest=1
listen=1
addnode=10.80.233.12:19000
port=19000
rpcport=19001
server=1

After a day or so, or around 100000 blocks, the two servers disconnect. getpeerinfo shows no connections and the blockchain is forked. A restart is required to bring them back into synch.

This has happened consistently over the last couple of days. Does anyone know why and what we can do to fix it?