What are the Pros and Cons of Proxy Server Firewalls? – 1+1 …
If you value your security, you’ve probably heard about firewalls. Firewalls protect your data and information from being seen or accessed by outside software or users. Aside from being an excellent investment for businesses, they can also be for personal use. Any data that might be sensitive, such as financial data, personal information, and so on, should always be protected. The question is, what kind of firewall should you use? Today, we’ll be talking about proxy server Basics: Proxy Server FirewallsOther firewalls allow information packets to pass through a proxy. But with this firewall, the proxy works as an intermediary. This creates and runs the process on the firewall, which mirrors the information transfer as it seems to be running on the end host. This keeps intruders from finding your network’s location from information packets, which strengthens your network’s you conclude that proxy firewall is worth the try, take note of its pros and cons osProtectionThe main advantage of these firewalls is they protect your data and information. When you’re using the internet, you’re giving away information about yourself. You are ‘seen’ by every website you access. Your personal information may be even vulnerable. By using go-betweens, or proxy server firewalls, you’re using an anonymous assistant who is seen, instead. This way, your personal information is more lated Content: How Does A Network Security Firewall Work? AccessAnother thing that they can do for you is to allow access to websites that are either blocked or difficult to access. Restrictions placed on website access can sometimes be circumnavigated with the help of proxy server firewalls. SpeedProxy server firewalls often have excellent cache systems. Because of this, using them may mean that your browsing speed is positively affected. You may also find your access data nsSeeing DataWhile it can be a good thing that proxy server firewalls have a great cache system, it also has its disadvantages. For instance, they may be able to read your secured information that can lead to a data breach. That’s why it’s important to use high-quality firewalls only. It may be worth spending a few extra dollars to make sure everything is in the SystemUnfortunately, not all applications are proxy aware. Because of this, some applications may ignore them. It’s important to contact a professional to help you select the best option for ttlenecksThe overhead in setting up proxy server firewalls might increase. And because of this, it may take some extra time to implement them. You may also find that performance times slow due to the extra layer of security. To ensure that your firewalls function as intended, it’s best to hire a professional to configure lated Content: All About the Basics: 4 Types of Network FirewallsSo, should you consider investing in this firewall? It all depends on your cybersecurity needs. Start weighing these pros and cons, and feel free to take a look at other options too. Once you’re ready to learn more about how proxy server firewalls can serve you, contact us at 1+1 Technology today!
5 Advantages and Disadvantages of Proxy Server
What is Proxy? A Proxy is an intermediary between the clients and the server. For the people who are more conscious about their security will probably know about proxy. Through the proxy the client can access the information stored in various servers. It is used for various other purposes as well.
Most often it is compared with the VPN since both Proxy and VPN has similar functionalities. Proxy servers especially the free ones has its own advantages and disadvantages. Identifying its benefits and drawbacks will help you to decide whether it will be best for your business.
In this article, you will get the information on 5 Advantages and Disadvantages of Proxy Server | Limitations & Benefits of Proxy Server. Finally from this post, you will know the pros and cons of using proxy.
Let’s get started,
Advantages of Proxy
Proxy has been used primarily for masking the IP addresses. From this way any hacker trying to access your computer will not be able to do it so. While trying to access your computer, they will be logged into the proxy instead of the real IP address. Besides that the websites will not be able to track you since the original IP address is hidden. This way a proxy can provide anonymity to the user.
While you are browsing the web, there are high chances you may end up visiting malicious websites. In case if you visit such as site, the malware will sneak onto your system causing irreversible damages. Likewise there are numerous untrustworthy websites setup by hackers. Accessing one of them will end up placing all of your personal informations at risk. When you are using a proxy server, your system will not make the request directly to those sites. Always the proxy end will be facing the threats imposed by such sites. This allows your system to maintain maximum protection.
3. Unblock Websites
Many website owners restrict contents to certain geographical areas, basically due to its copyright law. Any person living outside those regions will not be able to access those contents. Since the IP address is hidden using proxy you can access those geo-restricted sites regardless of your location. Additionally some ISPs and organizations too impose restrictions to certain websites. Proxy can be used to bypass these restrictions too.
Some of the proxies use cache data. Once a user visits a website, these proxies will store all the necessary informations through the cache data. Due to this, when a user visits a same page, the page will be displayed faster. However this can happen only if the proxy has the necessary cache data from the website. Otherwise, it needs to request it from the remote server. In this case you may fail to notice any page loading speeds.
5. Control Contents
Same as how a proxy can be used to unblock websites, it can be used to restrict access to specific sites. Organizations can use proxy to prevent its employees from logging onto certain websites, so that they can improve their overall productivity.
Disadvantages of Proxy
The cache data the proxies use can remember all of the personal informations including that of passwords. This will not be a problem unless someone from outside gathers them. However the problem may comes from the side of proxy itself. There are chances where employees working under proxy misuses these informations. Therefore, it is always recommended to invest in a proxy from a legitimate service provider.
Although proxies provide the benefits of anonymity, it lacks on the side of encryption. Most proxies use SSL certificates for encrypting the data. This isn’t strong enough to prevent today’s attacks. Especially from the attacks known as SSL stripping. Hence, when the SSL type encryptions are used, the data traveling through the server will be less secure.
Proxy may not always be compatible with your local network. Both the proxy and the network has its own configurations. In this case if you need to use the proxy in your location network, you have to either configure them or go with a proxy that completely matches with the network you are using.
Setup and maintenance of a proxy server can be costly. Even though large organizations can easily cover up this expense it will be not for small businesses. Besides installation there are various other expenses involved here.
The configurations of the proxies are pre programmed for one specific goal. Therefore, there must be some coding that must be done to fulfill one’s requirement. But the configurations of a proxy can be quite difficult. It must be made perfectly in a way that no any ports are left open, so that no hackers can spy on your personal informations.
Pros and Cons of Proxy Firewalls – Network Security – InformIT
This chapter describes the basics of proxy firewalls and how they may fit into your security architecture. Although proxies are not as popular as they once were, they can still offer value when deployed appropriately. This chapter will help you to understand how proxies work, what their strengths and weaknesses are, and when you may want to use them.
This chapter is from the book
In this chapter, we introduce you to proxy techniques and how they
have been used to create proxy firewalls. Proxy firewalls serve a role similar
to stateful firewalls. Both are designed to allow or deny access between networks
based on a policy. The method they use to accomplish this is very different,
though. As described in the last chapter, with a stateful firewall, network
connections flow through the firewall if they are accepted by the policy. This
type of firewall acts like a router, passing packets through that are deemed
acceptable. In contrast, a proxy firewall acts as a go-between for every network
conversation. Connections do not flow through a proxy. Instead, computers communicating
through a proxy establish a connection to the proxy instead of their ultimate
destination. The proxy then initiates a new network connection on behalf of
the request. This provides significant security benefits because it prevents
any direct connections between systems on either side of the firewall.
Proxy firewalls are often implemented as a set of small, trusted programs
that each support a particular application protocol. Each proxy agent has in-depth
knowledge of the protocol it is proxying, allowing it to perform very complete
security analysis for the supported protocol. This provides better security
control than is possible with a standard stateful firewall. However, you only
receive this benefit for the protocols included with the proxy firewall. If
you must allow the use of a protocol that your proxy firewall does not specifically
support, you are reduced to using a generic proxy. Generic proxies do not have
any in-depth knowledge of the protocols they proxy, so they can only provide
basic security checks based on the information contained within the headers
of the packets (IP address, port, and so on).
This chapter describes the basics of proxy firewalls and how they may fit
into your security architecture. Although proxies are not as popular as they
once were, they can still offer value when deployed appropriately. This chapter
will help you to understand how proxies work, what their strengths and weaknesses
are, and when you may want to use them.
Fundamentals of Proxying
A proxy acts on behalf of the client or user to provide access to a network
service, and it shields each side from a direct peer-to-peer connection. Clients
needing to communicate with a destination server first establish a connection to
the proxy server. The proxy then establishes a connection to the destination
server on the client’s behalf. The proxy server sends data it receives from
the client to the destination server and forwards data it receives from the
destination server to the client. In the process of performing this role, the
proxy server can examine the requests to ensure they are valid and allowed by
The proxy server is both a server and a client. It is a server to the client
and a client to the destination server. One way to keep this straight is to call
the listening end of the proxy the listener and the initiating side of
the proxy the initiator. This leaves the terms client and
server for the endpoints.
Another important issue is whether the proxy is transparent to the client.
Originally, all proxy servers required clients to be aware of them. This meant
that a client’s software would need to include specific code to properly
use a proxy, and the client would need to be configured to send its requests to
the proxy. Client software that was not proxy aware could not communicate
through the proxy.
Two approaches were used to overcome this software burden. First, an industry
standard proxy protocol was developed. Called SOCKS, it allows client software
developers to easily add proxy support to their products. We’ll be covering
SOCKS in more detail later in this chapter. The second approach was the
development of transparent proxies. These products intercept connection requests
by masquerading on the fly as the destination server being requested by the
client. The transparent proxy then goes on to make the request to the
destination server for the client. Using this method, the client is fooled into
thinking that it is communicating directly with the server, while the proxy is
actually handling the communications.
The following is an example of how a typical request from an internal client
to an external server would be handled by a transparent proxy firewall:
The client requests an Internet service, such as HTTP, FTP, or
The client computer starts by attempting to set up a session between the
client and the server. Assuming the Internet service being requested is TCP
based, this begins with the client sending out a SYN packet sourced from the
client’s IP address and destined to the server’s IP address.
The proxy firewall intercepts the connection request and, if allowed by
policy, replies with a SYN-ACK packet sourced from the destination server’s
IP address. It is important to mention that this does require the proxy to be on
the network path between the client and the server.
Upon receipt of the proxy’s SYN-ACK packet, the client finishes the
three-way handshake by sending out the final ACK packet, again destined to the
server’s IP address. At this point, the client thinks it has a valid TCP
connection to the external server. In reality, it only has a connection to the
The proxy is now responsible for establishing a connection to the
external server. It accomplishes this by sending out a SYN packet sourced from
its own IP address and destined to the external server. Upon receipt of the
server’s SYN-ACK packet, it replies with an ACK packet to establish the
connection to the external server. At this point, the proxy has two valid TCP
connections for the session: one between itself and the client, and the other
between itself and the server.
Requests received over the client-proxy connection will be analyzed for
correctness and policy compliance. If they are acceptable, the proxy will make a
corresponding request using its proxy-server connection. Replies received over
the proxy-server connection will also be analyzed for correctness and policy
compliance and then, if acceptable, forwarded to the client over the
proxy-client connection. This will continue until either side of the
conversation terminates the connection.
A traditional, nontransparent proxy would similarly handle the request.
However, there would be no need for the IP address manipulations required by the
transparent proxy. Instead, the client would know about the proxy and would be
able to send the request directly to the proxy server’s IP address. In
addition, because the client is proxy aware, if there are any special proxy
functions for the client to choose from, the client can include this information
in the request.
Proxy firewalls are often implemented as dual-homed bastion hosts running a
set of proxy agents. Each agent supports one or more Internet protocols. The
degree to which each agent understands the protocols it proxies determines how
effective the agent can be in managing the connection. A generic agent that
supports standard TCP protocols will likely only be able to restrict connections
based on the TCP and IP headers (for example, IP address, port, TCP state). This
functionality is similar to packet filter firewalls. However, if the protocol to
be proxied is not standard, or if additional security functionality is desired,
more sophisticated agents are required.
A good protocol to use as an example is the File Transfer Protocol (FTP).
Remember from Chapter 2, “Packet Filtering, ” that FTP does not act
like a standard TCP protocol. Instead, FTP uses two different TCP connections to
enable file transfer. One (the command channel) is used to send instructions to
the FTP server, the other (the data channel) is used to transfer files (see
Figure 4. 1). This makes it impossible to support FTP with a generic proxy.
Unless the proxy agent was aware that this second TCP connection was needed, it
would not be able to accept the second connection, blocking the FTP protocol
from transferring files.
Figure 4. 1 FTP requires two TCP connections to transfer files across a
An agent specifically programmed to support FTP would be able to monitor the
individual FTP commands being issued over the command channel. It would be able
to watch for the command used to transfer a file and then begin listening for
the TCP connection used to transfer the file. In addition, by being protocol
aware, the agent has the ability to watch the FTP commands to detect suspicious
FTP was created during the early days of the Internet, when security was not
something the designers emphasized. The FTP protocol contains several,
well-known security flaws that have been repeatedly exploited. Even today, it is
not uncommon to locate FTP servers that are not properly protected. One classic
flaw is related to how the data channel is set up between a client and a
When the client wants to request a file from the server, one option it has is
to send a PORT command. PORT is used to configure the server
to establish a TCP connection initiated from the server to the client. The
format for the PORT command is as follows:
PORT h1, h2, h3, h4, p1, p2
The values h1 through h4 form an IP address (h1. h2. h3. h4). p1 and p2 are used
to specify the destination port using the following formula:
256 * p1 + p2
For example, if the client is at IP address 192. 168. 5. 12, it might issue the
PORT 192, 168, 5, 12, 4, 1
which would tell the server to transfer requested files to IP address
192. 12 using TCP port 1025. To actually cause the connection to be
established, the client uses the RETR command to request a file. At
this point, the server will initiate the TCP session to the client on TCP port
1025 and transfer the file across the resulting connection.
The vulnerability is introduced because the client can provide any IP address
and port to the PORT command. In some circumstances, this can allow an
attacker to bypass firewall restrictions. We will use the network shown in
Figure 4. 2 to illustrate this attack. This network is composed of a screened
subnet that contains a web server and an FTP server. To allow customers to
upload files to the company, the FTP server is set up to allow anonymous
connections. The web server is running a Telnet service to allow administrators
to access the system from the internal network. Unfortunately, the Telnet
service is susceptible to an invalid input attack that would allow anyone who
connects to the service access to the computer without authentication. The good
news is that the stateful inspection firewall is blocking all inbound network
connections from the Internet except packets destined to TCP port 80 on the web
server and TCP port 21 on the FTP server. This would prevent attackers from
establishing a connection to the Telnet service running at TCP port 23 on the
web server. On the surface it seems that even with the vulnerable Telnet
service, the firewall has effectively kept the network secure. This is just an
illusion, though, as the FTP server can be leveraged to reach the web
Figure 4. 2 Even though the firewall blocks non-HTTP access to the web server,
the FTP PORT command may allow attackers to access the web
server’s Telnet service.
The following steps would allow the attacker to bypass the firewall and
attack the vulnerable web server:
Use a normal FTP connection to upload a file to the anonymous FTP server.
This file needs to contain the exploit commands necessary to attack the web
Using the established FTP command channel, send the command PORT
192, 168, 5, 7, 0, 23. This will tell the FTP server that the next file request
should be sent to the web server using port 23 (for example, Telnet).
Again using the FTP command channel, send the RETR command
specifying the name of the file transferred during step 1. This will cause the
FTP server to initiate a TCP connection to the web server on port 23, then
transfer the contents of the file over the connection.
Assuming the file contains the commands or data necessary to exploit the web
server’s Telnet service, the attacker will have successfully bypassed the
firewall, gaining control of the web server.
A sufficiently sophisticated FTP proxy agent would have had little difficulty
blocking this attack at step 2. When the agent receives the PORT
command from the client, it could compare the parameters of the command to see
if the IP address matches the IP address of the client. If it does not, the
connection could be terminated and an alert generated. This is one example of
how protocol-aware proxy agents can prevent vulnerabilities that would be
difficult or impossible to eliminate using packet-filtering techniques.
Modern proxy firewalls provide proxy agents for a large set of Internet
protocols. You can expect the core Internet protocols, such as HTTP, FTP, SMTP,
DNS, and ICMP, to be supported by just about all the products. When selecting a
proxy firewall, though, you should look carefully at the set of protocols your
network will need to pass through the proxy. If a critical protocol is missing
from the product you are considering, you may be able fall back to a generic
proxy and live with the reduction in security enforcement. If the protocol you
are trying to support is nonstandard (such as FTP), you may need to choose
between the protocol and the firewall.
Frequently Asked Questions about proxy firewall advantages and disadvantages
What are the advantages and disadvantages of proxy?
Advantages of ProxyAnonymity. Proxy has been used primarily for masking the IP addresses. … Protection. While you are browsing the web, there are high chances you may end up visiting malicious websites. … Unblock Websites. … Performance. … Control Contents.Apr 9, 2020
What are the advantage of a proxy service firewall?
Advantages of Proxy Firewalls Proxy firewalls provide comprehensive, protocol-aware security analysis for the protocols they support. By working at the application layer, they are able to make better security decisions than products that focus purely on packet header information.Apr 22, 2005
What is the advantage of proxy?
Benefits of a Proxy Server. Proxies come with several benefits that can give your business an advantage: Enhanced security: Can act like a firewall between your systems and the internet. Without them, hackers have easy access to your IP address, which they can use to infiltrate your computer or network.