deployment fails with external network connectivity issues

Issue

After a successful deployment, further deployments are failing with the following error:

[stack@undercloud ~]$ openstack overcloud deploy --templates /home/stack/my-site-1 -t 120 --control-flavor control --compute-flavor compute --compute-scale 1 --neutron-network-type vxlan --neutron-tunnel-types vxlan --neutron-public-interface eth4 --ntp-server 10.10.10.10 --libvirt-type kvm -e /home/stack/network-environment.yaml
Deploying templates in the directory /home/stack/my-site-1
/home/stack/.ssh/known_hosts updated.
Original contents retained as /home/stack/.ssh/known_hosts.old

ERROR: openstack Unable to establish connection to http://10.10.10.11:35357/v2.0/tenants