$.$After concerns about security, an administrator has been asked to carry out a review of how network traffic is being directed across a company network.

The administrator needs to block SSH access to the SSH server on Net $1$ from Host $1.$ Host $1$ should be able to access each of the computers on Net $2.$ The web server on Net $3$ should be reachable from Host $1.$ Host $1$ as well as Net $2$ should not be able to access the Internet.

Using the following diagram $($Figure $2),$ the administrator has asked for help with the design and has asked you to write simple statements in plain English showing how you would achieve the above objectives. Note: you should aim to identify hosts and networks by using their addresses.

Described image

Figure $2$: Network diagram

Figure $2$: Network diagram

Please note $-$ for this part of the question, you are not being asked to create a Cisco Access Control List $($ACL$)$ of manipulate $($subnet$)$ any IP addresses.

$(8$ marks$)$

b$.$Whilst implementing the above scenario, the administrator discovered that Host $1$ is unable to communicate with Net $2.$ Investigation of the router has revealed the following access list statement:

allow udp host $192\mathrm{.}168\mathrm{.}1\mathrm{.}1192\mathrm{.}168\mathrm{.}11\mathrm{.}0$ eq $67$

i$.$Break this statement down into its component parts, describing what each part is doing.

$(6$ marks$)$

ii$.$What process is happening between Host $1$ and Net $2?$

$(3$ marks$)$

iii.Why do you think Host $1$ is unable to communicate with Net $2$ and what can be done to rectify the problem?

$(3$ marks$)$

c$.$

i$.$Describe what type of addressing scheme is in use across Net $1,$ Net $2$ and Net $3?$

$(1$ mark$)$

ii$\mathrm{.}120$ IP addresses have been allocated$/$assigned to PCs on Net $2$:

What is the useable number of addresses now available on this network? Please show your working.

$(2$ marks$)$

What is the total number of addresses now available on this network? Please show your working.

$(2$ marks$)$