Network Routing Switching Assignment

Question 2:

• Starting IP address of ABEC Pvt Limited= 172.154.60.0
  Number of bits contained in network=24
  Remaining bits in network for host address= 32-24=8 (In 32 bit IPv4 Network address)
  Network Prefix address =172.154 or 10101100. 10011010
  Host Part=60.0 or 00111100.00000000
  Total Number of Hosts=2^remaining bits
  =2^8= 256
  Where 2 of host are arranges for subnet masking so actually available number of host in network =256-2= 254.
• Starting address of network is 172.154.60.1 because 172.154.60.0 is reserved for default network routing switching address.
  First subnet with 120 address can range from: 172.154.60.1 to 172.154.60.119
  Second subnet block with 60 IP addresses range from: 172.154.60.120 to 172.154.60.179
  Third subnet block can contain addresses for 30 devices: 172.154.60.180 to 172.154.60.208
  Also 172.154.60.209 is occupied for broadcasting purpose in subnet block.
  Forth subnet contains address range: 172.154.60.210 to 172.154.60.221 for 12 IP devices.
  The last usable IP address for network is 172.154.60.254
• Address up to used in network:  172.154.60.221
  Possible final addresses in network:  172.154.60.254
  number of addresses those are not yet occupied = 254-221= 33 addresses

Question 3:

• Packet size arrived at router=1500 Bytes
  Excluding header information, actual packet size=1480
  Number of fragments= 3
  MTU at X.25= 576 Bytes
  First fragment length= 552 Byte data+20 Byte IP header =572 Bytes
  Offset: 0
  Byte range: 0- 551 Bytes
  Second fragment length= 552 Bye data+20 Byte IP header
  Offset: 69
  Byte range: 552-1103 Bytes
  Third fragment length= 552+20 Byte IP header
  Offset: 69+69= 138
  Byte range: 1104- 1480 Bytes
• MTU size for X.25= 576 Byte
  Initial packet has no offset thus, it is 0.
  Offset is multiple of 8 and calculated as data/8 for second packet. Thus offset of second fragment will be= 552/8= 69
  Offset for third fragment= 69+69 = 138
• When incoming data packet (excluding IP header) has size greater than MTU size for destination then packet is decided to fragment where fragmentation may be in size equal to less than MTU including IP header information. For instance, X.25 has MTU size 576 Byte. Thus, fragment coming towards X.25 may be of maximum size 576 Byte. However, maximum possible size is 572 Bytes due to arrangement of data and offset in multiple of 8.?

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Question 4:

• In internet, Autonomous systems represent the devices those are connected to each other with same network address prefix. Same network prefix may be used to serve specific units like organization, department or team. Autonomous system works as routing policy rather than a network. arrangement. Devices in AS share their routing information to neighbour devices in network so that same routing configuration can be known to all devices. Inter-domain routing or BGP and Interior Gateway Protocol are used to share routing information security to other domains and destinations in network. Inter-domain protocol is used to connect with other domains in internet. Normally BGP router shares IP prefixes to all domains in internet where domain starting with desired prefix addresses replies to get data from BGP. Later domain delivers the packet to autonomous system in it. Every autonomous system use unique autonomous system number (ASN) which is used inside domain to identify the right destination for BGP packet. Intra-domain routing protocols are used to identify the destination within same domain in internet. In this manner, autonomous systems, inter domain and intra domain routing are interrelated to provide services in internet.
• Major Intra domain routing protocols:
  Routing Information Protocol (RIP)
  Interior Gateway Routing Protocol (IGRP)
  Open Shortest Path First (OSPF)
  Exterior Gateway Routing Protocol (EGRP)
  Intermediate system to Intermediate system (IS-IS)
  Major Inter domain routing protocols:
  Border Gateway Protocol (BGP4)
  Gateway to Gateway Protocol (GGP)
  Exterior Gateway Protocol (EGP)

Similarities between intra domain and inter domain routing protocols :

• Distance vector and link state algorithm is used in both the protocols to reach the destination in internet and domain.
• Both protocols identify the cost and delay to reach the destination fast and securely in internet.

Differences between both:

• Inter domain routing uses network prefix to reach destination domain where ASN is used inside domain to reach the destination device.
• Inter-domain routing deals with domains so which are smaller in number in comparison of overall devices in network. Therefore, it is faster than intra domain routing.

Need of different protocols in internet:

• The structure of domains and autonomous systems inside domain is different in number of devices and their connections. Therefore, the security and implementation differences lead the use of different protocols in internet.
• Different protocols are used according to data to be sent. For instance, TCP can be used for secure end to end communication where UDP protocols can be used to send larger data files with adequate security.
• Routing to specific device in network is being difficult because of scalability requirements, anonymous route insertion and decreased responsiveness. Extensive use of internet in computer devices is leading the problem of scalability as distant routers are difficult to manage and position in network to cover all devices. The insertion of anonymous route is affecting the performance and security in network as unwanted routes are used by hackers to destroy the connectivity and communication. Network Security in routing is being compromised by observing and assuming the patterns associated with packages. Improper and open configuration for routing is encouraging attackers to insert their traffic in network to achieve competitive advantages. Robustness and responsive capability of network is vulnerable to security due to unwanted traffic and route in network. As part of logical challenges, organizations are facing issues to fight against DoS attacks as filtering of packets and associated addresses are difficult.
• Embedded routing offers a mechanism to a large number of Ethernet and Wi-Fi devices through a single dial up device. In built code is to facilitate. DHCP and NAT technology in network routing. From the number of applicability, normally it is effective to aid the services of sensors to network which all are connected to single internet source. Also embedded routing is useful to handle different devices from different manufacturers and vendors to connect them with source of internet in network so implementer needs not to worry to configure each and every device in network. Extensible routing is another routing normally used in scalable and versatile networks. The profitability with extensible routing is high as it is effective to connect with cloud computing services. However, both the routing mechanisms are similar to it each in many senses. They provide high end connectivity solution to the problems of network scalability, effectiveness and performance. They also demand very less maintenance in order to provide high security. Al Though, Extensible routing is effective to use in cloud services and offers cost beneficial, technology integrated, vast supported services and cross platform solution. This is useful to add wireless devices and sensors to cloud network.
• In order to deal with routing challenges, Routing as services is incredibly accepted solution. The proposal of basic routing switching as services in network is capable to eliminate unwanted and independent routes in network by recognising such devices with implementation of dynamic DHCP and NAT technology which are embedded in routing device. Proposed Implementation of path vector algorithm and RSP can avoid unwanted AS in network to block insertion of routes. Access control list (ACLs) is used to chunk unknown routes in network by rechecking the packets on receiver. Firewall can be used to implement ACL so that all incoming packets can be examined for their permissions to access with certain resources in network. RAS is used to aggregate the traffic in network and then priority is decided to packages in network. This mechanism is effective to deliver high performance and security in network communications. In order to deliver high performance at gateway, customer policy specification and avoidance of conflicts can be used to.