Perimeter Router is also known as the border router. It is
being used to connect between trusted and untrusted network. However if the
perimeter router is not properly configured, it will adversely compromise the operations
of the trusted network (Dunning, 2011) .
For instance, a poorly secured perimeter router will result
in denial of service (DoS), which will compromise the availability of the
network (Dunning, 2011) . It will happen when
the router is ineffective in filtering redundant network traffic (Dunning,
2011) .
On the other hand, a well-secured perimeter router will be able to prevent any
reconnaissance from taking place, hence reducing the risk of being attacked (Dunning,
2011) .
Figure 1 (Network
Diagram)
To prevent any attack from taking place, the perimeter
router must filter all the incoming packets. One of way will be ensuring that
the source IP address must not contain the IP address of the local network.
This is one of the sign of IP spoofing (Dunning, 2011) .
Internal router will be referring to router that is not
between the trusted and untrusted network. It will help to divide the local
area network of into smaller network. In this way it will help to speed up the
speed of transfer since it will have smaller routing table than before (Cooney, n.d.) .
A firewall is referring to filtering of unwanted packets in
order to protect the host from any attack (Tyson, n.d.) .
The following video will be explaining the uses of firewall:
There are several methods to control traffic in firewall.
These include packet filtering and stateful inspection. In packet filtering,
the packets must go through a set of filtering. Only those packets managed to
make it will be sent to the system (Tyson, n.d.) .
In stateful inspection, only key parts of the packets will
be checked against the database. The characteristic of the outbound information
will be checked against the inbound information. If it matches reasonably, the
packet will be allowed (Tyson, n.d.) .
Reference
[Network
diagram]. Retrieved May 1, 2012, from: http://www.aniltj.com/blog/2007/03/23/DesignPatternsAndSOARuntimeInfrastructure.aspx
Cooney, R. (n.d.). Subnet Addressing. Retrieved
May 1, 2012, from NetworkComputing:
http://www.networkcomputing.com/unixworld/tutorial/001.html
Dunning, D. (2011, November 13). What Is a
Perimeter Router? Retrieved May 1, 2012, from eHow:
http://www.ehow.com/info_12198351_perimeter-router.html
Tyson, J. (n.d.). How Firewalls Work. Retrieved
May 1, 2012, from howstuffworks:
http://computer.howstuffworks.com/firewall1.htm
Hello, Adi here.
ReplyDeleteI think that this post is quite good. You managed to explain the Perimeter router clearly and simply. The video you've provided about the firewall was also helpful. However, I think you could have explained more about the internal router and how the perimeter router, firewall, and internal router work as a whole. You could have added some information about a DMZ as well.
The diagram was also not so clear. It's only relation to this post is the perimeter router. There wasn't a reference there to the firewall or internal router. Perhaps you could have used a different one?