Elasticsearch warning - WARN: org.elasticsearch.discovery: [...] waited for 30s and no initial state was set by the discovery

I added a new elasticsearch node and got puzzled by the error:

log4j, [2015-05-12T10:42:18.996]  WARN: org.elasticsearch.discovery: [logstash-id.xxx.in-25379-6424] waited for 30s and no initial state was set by the discovery
^C

Finally, it turned out  that iptables was blocking access to elasticsearch host. So, after adding the firewall rules, things worked flawlessly.

Allow elasticsearch in iptables(firewall) rules:

#Allow elasticsearch access
iptables -A INPUT -s 10.4.0.45 -i eth0 -p tcp --dport 9200 -j ACCEPT
iptables -A OUTPUT -d 10.4.0.45 -o eth0 -p tcp --dport 9200 -j ACCEPT