International Journal of Engineering Trends and Technology (IJETT) – Volume 5 Number 6 - Nov 2013
Performance Characterization of
DNS Relay in Geographically
Distributed LAN
Ridhi#1, S.Charanjit Singh*2
# Research Scholar, Computer Science, RIMT, Mandigobindgarh, India
*Assistant Professor, Computer Science, RIMT, Mandigobindgarh, India
Abstract— DNS is a distributed scalable, reliable naming system
that translates symbolic domain names to IP address and viceversa. Whenever there is request for a particular host, via, Web
browser, Local DNS resolver contact DNS server to determine
server’s IP address then it forwards request to next DNS server
at next higher level in hierarchy. When DNS server receives
query it checks whether it is based on resource records stored in
its local cache. If found response from cache to requesting client
A.
then query is completed and if name not found even at the
ROOT DNS, assistance is taken from DNS server to resolve the
name.DNS caching reduces access time for the host for data
transfer and number of iterative requests processed by name
server. Thereby increasing performance and reducing DNS
query traffic on the network. In this paper security feature of
DNS is not included.
Keywords— DNS, TTL ,LAN ,IP, Cache ,MAC
I. INTRODUCTION
With the growing number of users using internet services and
applications , more and more number of users are increasing
which has declined the performance of network. In past years
many techniques have been used to improve the scalability,
availability, and performance of network. Domain Name
System has proved to enhance the performance of a network
in terms of network bandwidth. Bandwidth Management
assures efficient use, by assigning large amount of available
bandwidth. The components to optimize distributed LAN
network bandwidth are traffic management and caching.
These applications alter traffic , delivery of content and usage
patterns while requiring additional bandwidth, reduced latency
and less jitter. Traffic Management is effective for optimizing
distributed LAN Bandwidth. As number of users are
increasing on the network so more and more DNS queries are
to be generated ,which lead to use of more and more
bandwidth ,so there is need to localise DNS so that number of
DNS queries can be reduced. Less bandwidth leads to slow
application response time and poor voice and video user
experience resulting in less . In distributed LAN, user
computers are widely distributed over large geographic areas,
less bandwidth results in lack of speed. So localisation of
DNS will effectively increase the performance of network.
DNS controls IP address returned to the client during the
name resolution operation. These returned IP address
ISSN: 2231-5381
determines which server is contacted, or which ISP is
used.The base of our analysis is on observations of clients
request to access a web page from LDNS contacting
authoritative DNS servers in a large Distribted network . In
this paper, we consider the impact of DNS-based network
control.
Distributed LAN Network
Distributed network is a distributed computer network
consisting of many software components on many computers,
but run as a single system and are connected by a local
network, or they can be geographically distant and connected
by a wide area network. So the reliability and scalability of
this distributed network determines whether user demands are
to be supported or not. Communication protocol like TCP/IP
provides basic connectivity between networks. Various
Internet applications like electronic mail, Web browsing
provide the tools and services that allow workers to share
information across one or more local area networks (LANs), a
wide area network (WAN), or the Internet.
II. RELATED WORK
There has been considerable work in the DNS area ranging
from characterization on a local and wide-area network.
Traffic problem in the network occurs due to processing of
large number of queries on Root DNS has also been
characterized in previous works. In [5], the authors collect
local area traces of DNS and traffic to characterize DNS
performance and caching behavior Recent work to be done is
to characterize and improve the performance of
Geographically Distributed LAN network by the use of Local
DNS that will improve bandwidth of network and reduce time
taken for processing of queries. DNS Caching is responsible
for processing iterative requests and thereby reducing the
access time for the host and for the data transfer.
III. METHODOLOGY
Domain Name System Concepts
A DNS server provides name resolution for TCP/IP-based
networks. That is, it makes it possible for users of client
computers to use names rather than numeric IP addresses to
identify remote hosts. A client computer sends the name of a
remote host to a DNS server, which responds with the
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International Journal of Engineering Trends and Technology (IJETT) – Volume 5 Number 6 - Nov 2013
corresponding IP address. The client computer can then send
messages directly to the remote host's IP address. If the DNS
server does not have an entry in its database for the remote
host, it can respond to the client with the address of a DNS
server that is more likely to have information about that
remote host, or it can query the other DNS server itself. This
process can take place recursively until either the client
computer receives the IP address or it is established that the
queried name does not belong to a host within the specific
DNS namespace. The Domain Name System is essential part
of Internet. It’s primary purpose is to resolve symbolic name
to IP addresses and retrieves information associated with the
domain name. The name space is the structure of the DNS
database an inverted tree with the root node at the top. Each
node has a label the root node has a null label, written as “”
read left to right as shown in Fig 1 . When a DNS client issues
a recursive query to a local name server, the server attempts to
resolve the name completely with full answers or with an error
by following the naming hierarchy all the way to the
authoritative name server. The client requesting queries
receive address information only from the local name server.
""
edu
com
nominum
west
east
dakota
tornado
metainfo
berkeley
gov
nwu
int
mil
net
nato
army
uu
org
iterative requests processed by name server. Thereby
improving network bandwidth efficiently.
Fig. 2 shows components of DNS
III.RESEARCH METHODOLOGY
How Local DNS Works
When a client needs an IP address for a specific domain name,
it queries DNS server to resolve the name. The local DNS
server then checks its local record and finds the corresponding
IP address then it response back with the IP address to the
request made by client.
If Local DNS doesn’t find record related to the requested
domain name then two ways can be followed that to resolve
domain name into corresponding IP address known as
recursive search or iterative search .When a DNS client
requests a recursive query to a local name server, the server
attempts to resolve the name completely or with an error by
considering the server hierarchy to the authoritative name
server and the client requesting queries receive IP address
information only from the local name server.
www
Fig 1 shows namespace of DNS in inverted tree structure
B. DNS Components
The various DNS Components are the name space, the servers
and the resolvers ,as shown in Fig 1.The name servers store
information about the name space in units called “zones” and
a loaded complete zone is said to be authoritative zone. More
than one name servers are authoritative for the same zone that
spreads the load and also single name server is authoritative
for many zones. The two main types of servers that work on
DNS are Authoritative that maintains the data .It works as
Master-Slave master where the data is edited and Slave where
data is being replicated to. Second one is Cache server that
stores data obtained from name servers. DNS must be highly
scalable and offer good performance even under high load.
Use of caching and effective naming system of DNS is helpful
in reducing load on the root server at the top of the name
space hierarchy and caching helps in limiting delays at the
client side and access time for host by reducing number of
ISSN: 2231-5381
Fig. 3 shows Local DNS server
The local name server shown in Fig 3 and Fig 4 requests
other DNS servers in the hierarchy on behalf of the client.
Whereas upon receiving an iterative query, the local name
server first check DNS data within its record, if the local name
server does not have DNS information within itself then it
consider another name server for processing the query.
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International Journal of Engineering Trends and Technology (IJETT) – Volume 5 Number 6 - Nov 2013
TTL value sets to a very small value so that it provides fast
response.
IV. Conclusions
In the present study, an attempt is made to study the effect of
relay DNS over the distributed LAN or WAN. The caching of
the DNS in the local server is effective in handling the
repeated request which is meant for the local domains and
virtual private network having dedicated bandwidth to access
the central services. This proposed design of the geographical
distributed network will be quite effective and responsive to
the queries from the local computers.
Fig. 4 shows Local DNS server processing iterative query
Solution by improving performance
Corporate and distributed LAN network performance can be
improved so that it is more reliable and efficient to be
handled.
Design of Geographically Distributed Network
Segmentation of Network
Design of distributed LAN should be around switching
solutions which uses simple MAC addresses or VLAN ID
information to forward traffic at non-blocking wire speeds. It
offers lower cost per switched segment. This allows us to
reduce the number of users per segment and to provide
dedicated switched ports. In addition, switches create a single
logical LAN and keeping the load balancing on the DNS
server.
DNS Cache
DNS cache eliminates collisions and allows network to
perform efficiently. It reduces access time for host and
transfer of data and number of iterative requests performed by
naming server, thereby improving performance of network.
Responses to name resolution requests have an associated
time-to-live (TTL) value that determines how long the
response should be cached by the client’s local name server .If
ISSN: 2231-5381
ACKNOWLEDGMENT
The author would like to thank the Editor, respected guide and
other faculty members for their valuable suggestions and
expert comments.
REFERENCES
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[3]Castro, S.Wessels, D.Fomenkov, M.
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[4]Xin Chen, HainingWang, Shansi Ren, “Maintaining Strong Cache
Consistency for the Domain Name System”, IEEE, Student Member,
IEEE.
[5] J. Jung, E. Sit, H. Balakrishnan, and R. Morris, “DNS
performance and the effectiveness of caching. IEEE/ACM
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[6] Wessels, D, “Is Your Caching Resolver Polluting the Internet?
SIGCOMM Network Troubleshooting Workshop, 2004.
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