We have learned lots of networking components and protocols. If you were a network administrator in a very large company, please try to draw your network topology and corresponding network components with the following settings.

• Your company subscribes an ADSL service, so you need to draw a central office, DSL access multiplexer, DSL modem, splitter, some links and routers in the topology. You should specify the type of links in the graph (e.g., telephone twist pair line, fiber, or coax). The transmission rate of the ADSL link is 300M/100M.

• Your company has a public IP range 12.34.56.0/24 obtained from the ISP, and the edge router (i.e., the nearest router to the subnet) has another public IP, 98.76.54.32, obtained from the ISP. Try to draw a routing table of this edge router.

• Your company has a local DNS server whose IP is 12.34.56.53 in the subnet, and it also serves as an authoritative DNS server to resolve all *.networking.com IPs.

• One of your host is served as a HTTP server who runs with IP 12.34.56.80 at TCP 80. It has a domain name www.networking.com. Show me a RR record (type A record) replied by the authoritative DNS server when a DNS client sends a query for resolving www.network.com. The RR format is (name, value, type, ttl).

• One of your host (12.34.56.31) is a HTTP proxy.

• Your company divides the /24 network into 4 smaller subnets, please draw

  four subnet and four internal routers with proper IPs. Also show the IP range and mask of each subnets in the figure. Also show the routing table of all four internal routers. Each routing entry should include an destination_ip_range and a link_interface_number (and you can name the interface number by your own). All the subnets use 1Gbps gigabit Ethernet.

• One of the host is your wireless access point (AP) whose IP is 12.34.56.11. The AP is also a NAT server and a DHCP server that uses a private subnet 192.168.0.0/24. The AP uses 192.168.0.1 as its private IP address.

• One of your host is the SMTP server and the POP3 server, and its IP is 12.34.56.25.