Ceph - 'apt-get install' Won't Ignore Ubuntu Xenial Bits

Issue

• While trying to install Ceph, 'apt-get install' won't ignore Ubuntu Xenial bits.
• I'm encountering 'unmet dependency' errors when trying to install ceph bits on Ubuntu Xenial:

$ sudo apt-get install ceph-mon
Reading package lists... Done
Building dependency tree       
Reading state information... Done
Some packages could not be installed. This may mean that you have
requested an impossible situation or if you are using the unstable
distribution that some required packages have not yet been created
or been moved out of Incoming.
The following information may help to resolve the situation:

The following packages have unmet dependencies:
 ceph-mon : Depends: ceph-base (= 10.2.2-29redhat1xenial) but it is not going to be installed
E: Unable to correct problems, you have held broken packages.

$ sudo apt-get install ceph-base
Reading package lists... Done
Building dependency tree       
Reading state information... Done
Some packages could not be installed. This may mean that you have
requested an impossible situation or if you are using the unstable
distribution that some required packages have not yet been created
or been moved out of Incoming.
The following information may help to resolve the situation:

The following packages have unmet dependencies:
 ceph-base : Depends: ceph-common (= 10.2.2-29redhat1xenial) but 10.2.3-0ubuntu0.16.04.2 is to be installed
             Recommends: ceph-mds (= 10.2.2-29redhat1xenial) but it is not going to be installed
             Recommends: librados2 (= 10.2.2-29redhat1xenial) but 10.2.3-0ubuntu0.16.04.2 is to be installed
             Recommends: librbd1 (= 10.2.2-29redhat1xenial) but 10.2.3-0ubuntu0.16.04.2 is to be installed
E: Unable to correct problems, you have held broken packages.