flashplugin-installer: Unable to download plugin from archive.canonical.com

Attempting to update flashplugin on Ubuntu Precise resulted in an error. Removing the package and reinstalling it resulted in the following:

$ sudo aptitude install flashplugin-installer 
The following NEW packages will be installed:
  flashplugin-installer 
0 packages upgraded, 1 newly installed, 0 to remove and 0 not upgraded.
Need to get 0 B/7,026 B of archives. After unpacking 139 kB will be used.
Preconfiguring packages ...              
Selecting previously unselected package flashplugin-installer.
(Reading database ... 210592 files and directories currently installed.)
Unpacking flashplugin-installer (from .../flashplugin-installer_11.2.202.275ubuntu0.12.04.1_i386.deb) ...
Processing triggers for update-notifier-common ...
flashplugin-installer: downloading http://archive.canonical.com/pool/partner/a/adobe-flashplugin/adobe-flashplugin_11.2.202.275.orig.tar.gz
Traceback (most recent call last):
  File "/usr/lib/update-notifier/package-data-downloader", line 234, in process_download_requests
    dest_file = urllib.urlretrieve(files[i])[0]
  File "/usr/lib/python2.7/urllib.py", line 93, in urlretrieve
    return _urlopener.retrieve(url, filename, reporthook, data)
  File "/usr/lib/python2.7/urllib.py", line 239, in retrieve
    fp = self.open(url, data)
  File "/usr/lib/python2.7/urllib.py", line 207, in open
    return getattr(self, name)(url)
  File "/usr/lib/python2.7/urllib.py", line 344, in open_http
    h.endheaders(data)
  File "/usr/lib/python2.7/httplib.py", line 954, in endheaders
    self._send_output(message_body)
  File "/usr/lib/python2.7/httplib.py", line 814, in _send_output
    self.send(msg)
  File "/usr/lib/python2.7/httplib.py", line 776, in send
    self.connect()
  File "/usr/lib/python2.7/httplib.py", line 757, in connect
    self.timeout, self.source_address)
  File "/usr/lib/python2.7/socket.py", line 571, in create_connection
    raise err
IOError: [Errno socket error] [Errno 101] Network is unreachable
Setting up flashplugin-installer (11.2.202.275ubuntu0.12.04.1) ...

So, it seems as if the URL archive.canonical.com is not resolving. However, googling around showed me that this error was intermittent and particular to certain geographies which is characteristic of DNS issues. So what I did was log into my work server and ping archive.canonical.com which gave me the IP 91.189.92.150 which was different from what the addressed resolved to on my other server (which was 32.1.6.124).

Fixing this is as simple as editing your /etc/hosts file and adding the following line at the bottom:

... and saving the file. This must, of course, be done as root (sudo). This should tell Linux that archive.canonical.com actually lives at 91.189.92.150 and not to bother using DNS to resolve it further.

Once this was done, I was able to update the package without any issues.