litecoind -regtest -server -rpcuser=rpc -rpcpassword=x -rpcport=10340  --datadir=/root/litecoind-simnet/ -port=12345

$ docker ps -a
CONTAINER ID        IMAGE               COMMAND                  CREATED             STATUS              PORTS                   NAMES
72b249cebeee        group1_node1        "litecoind -regtest …"   About an hour ago   Up About an hour    0.0.0.0:80->12345/tcp   group1_node1_1

This works on machine-B (no docker container involved):
litecoind -regtest -addnode=10.130.170.171:80 -rpcuser=rpc -rpcpassword=x -rpcport=10340  --datadir=/root/litecoind-simnet/ -port=12345

This does not work on a container on machine-B:
command: litecoind -regtest -addnode=10.130.170.171:80 -rpcuser=rpc -rpcpassword=x -rpcport=10340  --datadir=/root/litecoind-simnet/ -port=12345