Boostrapping: master not discovered yet, this node has not previously joined a bootstrapped (v7+) cluster

[code_share]

I am trying to bootstrap a 3 node cluster based on this guide:

https://www.elastic.co/guide/en/elasticsearch/reference/master/modules-discovery-bootstrap-cluster.html

node1 (master)

node.name: node01
discovery.zen.ping.unicast.hosts: ["node01.es.lan", "node02.es.lan", "node03.es.lan"]
cluster.initial_master_nodes: ["node01","node01.es.lan"]

node2

node.name: node02
discovery.seed_hosts: ["node01.es.lan"]
cluster.initial_master_nodes: ["node01","node01.es.lan"]

node3

node.name: node03
discovery.seed_hosts: ["node01.es.lan"]
cluster.initial_master_nodes: ["node01","node01.es.lan"]

First I have made sure to delete the data dir on all 3 nodes. I then first start node1 and wait for it to be up followed by node2 and node3

[2020-06-25T22:42:47,666][WARN ][o.e.c.c.ClusterFormationFailureHelper] [node01] master not discovered yet, 
this node has not previously joined a bootstrapped (v7+) cluster, and this node must discover master-eligible nodes 
[node01, node01.es.lan] to bootstrap a cluster: have discovered 
[{node01}{tjykvuzoTSeemHxxsYci-g}{6auh0orvTkOtOdo2KEHoRw}{node01.es.lan}{192.168.9.23:9300}{dilmrt}{ml.machine_memory=16656392192,
xpack.installed=true, transform.node=true, ml.max_open_jobs=20}, 

Any suggestions?

[Vinayak_Sapre]

@code_share
Assuming node01.es.lan resolves from all three nodes and 9300 on each host is accessible from other two nodes

node1 (master)

node.name: node01
discovery.seed_hosts: node01.es.lan
cluster.initial_master_nodes: node01

node2

node.name: node02
discovery.seed_hosts: node01.es.lan

node3

node.name: node03
discovery.seed_hosts: node01.es.lan