Description of problem:
As part of negative testing, I provided an invalid ip address to "--forwarder"
option while executing "ipa-dns-install".

Version-Release number of selected component (if applicable):
ipa-server-2.1.2-2.el6.x86_64

How reproducible:
Always

Steps to Reproduce:
1. Install IPA Server Master with all default options, do not install with
--setup-dns
2. ipa-dns-install --forwarder=1.1.1


Actual results:  setup of DNS for the IPA Server is successful.


Expected results:
ipa-dns-install: error: option --forwarder: invalid IP address 1.1.1: No
network interface matches the provided IP address and netmask

Additional info:
We can see this behaviour with "--ip-address" option:

[root@bumblebee ~]# ipa-dns-install --ip-address=1.1.1
Usage: ipa-dns-install [options]

ipa-dns-install: error: option --ip-address: invalid IP address 1.1.1: No
network interface matches the provided IP address and netmask
[root@bumblebee ~]#