A university has 150 LANs with 100 hosts in each LAN.
(a) Suppose the university has one Class B address. Design an appropriate subnet addressing scheme.
(b) Design an appropriate CIDR addressing scheme.
A router has the following CIDR entries in its routing table:
Address/mask Next hop
135.46.56.0/22 Interface 0
135.46.60.0/22 Interface 1
192.53.40.0/23 Router 1
default Router 2
(a) What does the router do if a packet with an IP address 135.46.63.10 arrives?
(b) What does the router do if a packet with an IP address 135.46.57.14 arrives?
Consider the three-way handshake in TCP connection setup.
(a) Suppose that an old SYN segment from station A arrives at station B, requesting a TCP connection. Explain how the three-way handshake procedure ensures that the connection is rejected.
(b) Now suppose that an old SYN segment from station A arrives at station B, followed a bit later by an old ACK segment from A to a SYN segment from B. Is this connection request also rejected?
You plug a new laptop into a wired Ethernet jack for the first time. You have already told the network administrators your MAC address, and can join the network with no further action on your part.
Assume that:
1. your DHCP server is 171.64.7.77,
2. your Ethernet address is 00:11:22:33:44:55
3. the IP address you'll be given is 171.64.7.22
4. the gateway IP address is 171.64.7.1
5. the gateway Ethernet address is 00:66:77:88:99:00
6. the netmask is 255.255.255.0
Let's consider the series of packet exchanges that will occur on the link for your laptop to send a single IP packet to 128.30.2.1. We assume that no packets are lost or discarded, and that no other packets are exchanged on the link.
a) Which of the following protocols are involved in the series of packet exchanges (check all that apply)? Options are
IP
ARP
UDP
ICMP
DHCP
b) How many packets will traverse the link ?
c) In which packet (sent or received) will your IP address be mentioned for the first time? Options are :
the 1st packet
the 2nd packet
the 3rd packet
the 4th packet
the 5th packet
d) How many packets (sent or received) contain the Ethernet address of the gateway?
e) How many packets (sent or received) contain the IP address of the DHCP server?
