External IP is unreachable

Hi Team,

We have one external IP that is unreachable from all the access and management nodes. All the configuration and other things are perfect as other IP's are working.

ICMP is enabled and other access IP is also working .

We did one work around to check this issue. We remove the network cable to another node and set another node as new access node and remove the access role from previous node 

We managed to do this all and still that external IP is unreachable. From customer application side as well it is unreachable as well. 

So please help me to resolve this as I couldn't find it's answer anywhere.

I have another query as well. If we need to add new replication IP in replication so do we need to pause the replication or we can directly set the IP to replication ...

I look forward to the answers