Refer to the internetwork in Figure 2 (A Simple Internet) and,
the address allocation table in Table 1 (Address allocation
table). The address allocation table identifies the IP and MAC
address(es) allocated to each host and router, on each of the
three networks. For instance, Host A is allocated MAC address:
H1MAC, Host B is allocated IP address: H2IP, Router 1 is
allocated IP address R1N1IP on network 1 (Net 1) and, MAC address:
R1N2MAC on network 2 (Net 2) etc.
|
Device |
Net 1 IP & MAC Addresses |
Net 2 IP & MAC Addresses |
Net 3 IP & MAC Addresses |
|
Host 1 |
H1IP, H1MAC |
N/A |
N/A |
|
Host 2 |
N/A |
N/A |
H2IP, H2MAC |
|
R1 |
R1N1IP, R1N1MAC |
R1N2IP, R1N2MAC |
N/A |
|
R2 |
N/A |
R2N2IP, R2N2MAC |
R2N3IP, R3N3MAC |
Table 1 – Address allocation table.
Answer the following questions:
(i) Explain why each Router is allocated two IP addresses and two MAC addresses.
(ii) Each of the datagrams labelled D1-D3 represent a single datagram that originated on Host A destined for Host B at different locations on its journey across the internetwork. For each datagram, identify the source and destination IP addresses explaining any changes of address.
(iii) Each of the frames labelled F1-F3 represent frames crossing each of the sub-networks. Each frame encapsulates a single datagram that originated on Host B destined for Host A. For each frame, identify the source and destination MAC addresses explaining any changes of address.