Here are things to check if Global IP address gets changed and NCs aren't connected or you can't launch to them:
On Global: usr/local/s2global/SymmetricDS/conf/global.properties
/etc/hosts
If the old IP address is still in /etc/hosts, you may not be able to restart rabbitmq on Global
On NC, but these may change automagically after you fix Global:
/var/lib/s2sys/s2netbox/conf/global.properties and sym_node sync_url
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