ceph setup weirdness

Three servers, each with 4 x hard drives (servers are labeled ceph3, ceph4, and ceph5)
Each server has three network ports (one unused and not defined, the other two each have an IP address defined).
Prepare the three Ceph nodes using Ubuntu 13.04, do an update,upgrade,dist-upgrade on all three
Install Ceph release
ssh-copy-id
Install ceph-deploy
ceph-deploy new ceph3 ceph4 ceph5
ceph-deploy install ceph4 ceph5
ceph-deploy mon create ceph3 ceph4 ceph5
ceph-deploy gatherkeys ceph3
ceph-deploy gatherkeys ceph4
ceph-deploy osd create ceph3:/dev/sda --zap-disk
ceph-deploy osd create ceph3:/dev/sdb --zap-disk
ceph-deploy osd create ceph3:/dev/sdc --zap-disk
ceph-deploy osd create ceph3:/dev/sdd --zap-disk
ceph-deploy osd create ceph4:/dev/sda --zap-disk
ceph-deploy osd create ceph4:/dev/sdb --zap-disk
ceph-deploy osd create ceph4:/dev/sdc --zap-disk
ceph-deploy osd create ceph4:/dev/sdd --zap-disk
ceph-deploy osd create ceph5:/dev/sda --zap-disk
ceph-deploy osd create ceph5:/dev/sdb --zap-disk
ceph-deploy osd create ceph5:/dev/sdc --zap-disk
ceph-deploy osd create ceph5:/dev/sdd --zap-disk
ceph-deploy mds create ceph3

at this point, the cluster was not happy, and the IP address of the third MON on Ceph5 was showing as 0.0.0.0/24

I then did:

ceph-deploy mon destroy ceph5

to get rid of it and the cluster eventually became OK