Deploy Oracle Management Agent failed with error: HTTPS url https://emserverHost:4900/empbs/genwallet is not reachable from the target node

Deploy Oracle Management Agent failed with error: HTTPS url https://emserverHost:4900/empbs/genwallet is not reachable from the target node

Today I tried to deploy Oracle Management Agent to one target host but always failed with the above error.

So I did below things to narrow down the issue

1. check if any firewall blocks the communication on port 4900
check /etc/sysconfig/iptables with root priviledge.

2. if it's not firewall issue, double check if host is reachable from target server. also double check if it's reachable via ipaddress

telnet host 4900
telnet ip 4900

In my case, telnet ip 4900 works but telnet hostname 4900 failed. so it means something wrong about dns hostname resolving.

It could be fix in dns level or add one more entry to /etc/hosts