Sure, I would recommend the below in sysctl:

  net.ipv4.tcp_keepalive_time=5
  net.ipv4.tcp_keepalive_probes=5
  net.ipv4.tcp_keepalive_intvl=1

This will tune the TCP keepalives to decrease the time it takes for most client stacks to realize a server has gone away. It should also be configured on the servers themselves that are participating in the cluster.

As for rabbitmq tuning I recommend these settings at a minimum:

  [
   {rabbit, [{tcp_listen_options, [binary,
                                  {packet, raw},
                                  {reuseaddr, true},
                                  {backlog, 128},
                                  {nodelay, true},
                                  {exit_on_close, false},
                                  {keepalive, true}]}
            ]}
  ].