$.$ Configure all the router interfaces $($BR$,$ R$1,$ R$2,$ R$3)$ with appropriate IP addresses. Be sure to set the hostname $($as appropriate$)$ also.

$2.$ Configure the BR and R$2$ and R$3$ such that only ssh access is allowed, and only from your groups network $(10.$XX$\mathrm{.}0\mathrm{.}0/16)$ and the core station $(10\mathrm{.}91\mathrm{.}0\mathrm{.}254).$ To provide access security to a juniper router you will create firewall rules and apply them to the loopback interface. For now we will create a rule which will only allow ssh $($tcp protocol $22)$ from $10.$XX$\mathrm{.}0\mathrm{.}0/16$ and $10\mathrm{.}91\mathrm{.}0\mathrm{.}254/32.$ We will create a "filter" in the firewall section. The filter will have three "terms". The filter and the terms have names that we specify $($and try to make descriptive$).$ The terms are processed in the order they are listed. Terms are each made up of two clauses, from and then. From is used to match while then is used to specify a action for the match.