COIT20261 Network Routing and Switching Term 1, 2019

COIT20261 Network Routing and Switching Term 1, 2019
Assignment item —Written Assessment-2
ANSWER TEMPLATE ASSIGNMENT TWO
Type your answers in the spaces provided
Marking criteria:
First Name:_________________________ Last Name:____________________________
Student ID: __________________________
Questions Mark
allocated
Mark
earned
Question 1: (10 marks) 5 each
table
Answer: Routing table of router R2:
Mask Network address Next-hop address Interface
255.255.255.0 200.11.60.0 140.21.0.1 /22 M1
255.255.255.0 200.11.60.0 150.3.0.2 /16 M1
255.255.252.0 140.21.0.0 150.3.0.2 /16 M2
255.255.252.0 140.21.0.0 200.11.60.1 /24 M2
255.255.0.0 150.3.0.0 140.21.0.1 /22 M0
255.255.0.0 150.3.0.0 200.11.60.1 /24 M0
255.255.255.0 200.11.60.0 140.21.0.1 /22 M1
The above routing table, shows each router interface, which has the mask, the
network address, and their next hope in the network (Kim and Ryu, LG
Electronics, 2010). Example for interface M1 its cover is 255.255.255.0 since
its /24, and the network address is 200.11.60.0. The interface has two hope
addresses 140.21.0.1 /22 and 150.3.0.2 /16.
The routing table of router R3:
Mask Network address Next-hop address Interface
255.255.192.0 161.22.0.0 150.3.0.3 /16 M2
5 max
5 max

COIT20261 Network Routing and Switching Term 1, 2019
Assignment item —Written Assessment-2
255.255.192.0 161.22.0.0 220. 10.40.1 /24 M2
255.255.0.0 150.3.0.0 161.22.0.1 /18 M0
255.255.0.0 150.3.0.0 220.10.40.1 /24 M0
255.255.255.0 220.10.40.0 150.3.0.3 /16 M1
255.255.255.0 220.10.40.0 161.22.0.1 /18 M1
255.255.192.0 161.22.0.0 150.3.0.3 /16 M2
Question 2: (5 marks)
a) When a router uses a classless addressing the whole address, space will be
divided into manageable blocks. If a packet is sent with a network address
between 161.22.0.0 to 16.22.0.192 to a specific final destination, the packet will
be sent to the next router first which checks whether the address is in its network.
If the address is not in the network, the packets will be sent to the next router
which checks whether the address is in the network and if not, it will be
forwarded until the packet reach the destination.
1 max
b) When a packet with destination address 150.32.0.17 arrive at R4, the following
calculations will be performed by the router to forward the packet (Shiota, NEC,
2016).
i. The mask (/16) is assigned to the destination address, and the
outcome is 150.32.0.0 which doesn’t match to the corresponding
network address.
ii. The mask (/18) is also applied to the destination address, and the
outcome is 150.32.0.0, and it matches to the same network
address. the next hope address and the interface number M1 are
forwarded to ARP for processing.
2 max
c) When the packet having destination address, 150.32.48.15 arrives at R3 a router
performs the following steps.
i. The mask (/18) is assigned to the destination address, and the
outcome is 150.32.48.0 which doesn’t match to the
corresponding network address.
ii. The second mask (/24) is also assigned to the destination address,
2 max

COIT20261 Network Routing and Switching Term 1, 2019
Assignment item —Written Assessment-2
and the outcome is 150.32.48.0 which doesn’t match to the
corresponding network address.
iii. The third mask (/16) is then assigned to the destination address,
and the outcome is 150.32.48.0 which doesn’t match to the
corresponding network address.
Since all masks on the router do not match the destination network, ARP will be
given next hope address 150.3.0.3 and the interface M0 since the packet needs to
be sent to other networks.
Question 3: (10 marks)
a) Autonomous systems and their relation to BGP
AS is an element of router rule for one network that is managed by a network
administrator or network operators on behalf of a single administrative unit like
business enterprise, university. It is a mutual routing domain that defines clearly
routing policy to the internet in the organization (Shue, Kalafut, and Gupta,
2012). It has a globally unique number which ranges from 1 to 64511. Examples
of the autonomous system are single-homed stub autonomous system and a
multi-homed stub autonomous system. The BGP enables the domain systems to
exchange routing data with other domain systems.
1 max
b) Inter-domain protocol is a routing procedure that ha been put in place amongst
two or more different networks. It focuses on getting to different domains in the
networks. The main interdomain protocol is the Border gateway protocol, which
allows exchange or transfer of information between domains in different
locations. The routing in interdomain occurs amongst the autonomous networks,
and the routing procedure ignores that the internet comprises the group of the
interconnected autonomous system.
Two max
c) Intradomain routing is a routing setup within individuals' network. It focuses on
reaching devices that are contained in the same domain. The routing rules found
in intradomain routing are; OSPF, RIP, EIGRP and focuses on assigning routes
Two max