Instructor: In this lesson, we're going to discuss proxies.
Proxy servers are devices that create a network connection
between an end-user's client machine
and a remote resource such as a web server.
These devices can either be physical,
hardware based appliances
or they can simply be a piece of software installed
on another server within our infrastructure.
Either way, these devices provide a few distinct benefits,
such as increased speed and efficiency in our networks,
increased security,
and additional opportunities to conduct auditing.
Increased speed and efficiencies are gained
when using a proxy because proxy servers
provide a function called web caching.
Essentially whenever a user requests a website
through a proxy, it retains a local copy in its cache.
Then when another user requests the same website,
instead of requesting it directly
from that web server over the slower WAN link,
the proxy server can simply provide the user
the cached copy that it saved locally inside of itself.
This saves time and bandwidth
and it works really well for static websites.
Now this technique doesn't work really well when
you're dealing with modern Web 2.0 websites.
Things like Facebook and Twitter and Reddit
and places like this that are going to use
user-generated types of content.
This is because every time you log in,
you're getting a personalized experience
individual to that user.
And this makes the caching not nearly as efficient.
The second benefit of a proxy server is increased security.
Now this occurs because each proxy can be configured
with a list of acceptable
and non-acceptable sites and they can then
block those sites that are deemed unacceptable.
So for example,
let's say an employee tries to access a website
containing pornography or gambling
while they're sitting at their desk at work.
Our proxy server might be configured to prevent that access.
Similarly, we can also block websites that are
known to host malware
and other content that we wouldn't want access
from our corporate networks.
Finally, proxy servers also provide our network
with additional auditing capabilities since they
can record each and every request that's made
by the users to go out to the wide area network.
These logs can then be used to determine
if an employee is attempting to access websites
that they're not allowed to access
such as gambling or pornography like we talked
about earlier.
But it can also tell us how much time
an employee is spending on any given website.
So if a manager is worried that an employee has
been surfing Facebook all day and not doing their job,
they can actually put in a request
for the system administrators to create a report
of that user's web browsing activity.
And they can query the proxy server and look
at the audit logs to determine exactly how much time
they spent on any given site if this is allowed
within the scope of the organization's policies.
Now, in one of my previous organizations where I served
as the IT director,
we started seeing our network
was slowing down over time
because we started adding more users
and we were getting worried about this.
So one of the things we did was we started evaluating
which websites were using the most bandwidth
by checking our proxy servers.
And, not surprisingly,
number one and number two was YouTube and Facebook.
Now this allowed me to go to upper management
and request additional money to buy more bandwidth,
or if they didn't want to give me that bandwidth,
we would then request to block these sites
so we could maximize the bandwidth we had
for real work functions and not
for people going on social media.
Now, in the case of this organization,
our leadership decided to block YouTube
because they didn't see a valid business reason
that would require our employees to be using YouTube
during working hours
instead of us buying a larger amount of bandwidth
from our internet service provider.
So they decided to save some money
and make it so the employees couldn't use YouTube.