I think you dbreplication is hosed,
you might want to run the following steps
utils network host (ip add, hostname of the sub ) on the pub
utils network host (ip add, hostname of the pub) on the sub
utils diagnose test on both the nodes.
utils network connectivity on sub
you can run this during production
If the above is good, try the following
utils dbreplication stop on sub (wait for it to complete)
utils dbreplication stop on pub (wait for it to complete)
utils dbreplication dropadmindb on pub (wait for it to complete)
utils dbreplication dropadmindb on sub (wait for it to complete)
utils dbreplication reset all on the pub.
hope this helps
Niket