1. Chapter 5b

2.  Upon completion of this chapter, you should be able to:  Subnet an IPv4 address to make separate networks out of one address given  Use the new subnet mask to identify the subnet  Assign IPv4 addresses to hosts within your network  Identify each subnet’s new network ID and broadcast address  Find the network, broadcast, or check if the address is a valid host address by working backwards

3. 5.1.3

4. Network Subnetwork Hosts

5.  Borrow bits from host portion to make new networks  Ask yourself…  How many networks do you need?  How many hosts per network are there?

6.  You MUST borrow at least 2 bits or leave at least 2 bits  Class C has 1 octet to borrow from  Class B has 2 octets to borrow from  Class A has 3 octets to borrow from  Remember the powers of 2  2 2 = 4  2 3 = 8  2 4 = 16  2 5 = 32  2 6 = 64 Remember 2 addresses you can’t use: Network & Broadcast

8. 1. 199.72.101.0-31 2..32-.63 (.33-.62) 3..64-.95 (.65-.94) 4..96-.127 (.97-.126) 5..128-.159 (.129-.158) 6..160-.191 (.161-.190) 7..192-.223 (.191-.222) 8..224-.255  Total Range #3  Useable Range #2  Network ID  199.72.101.64 /27  Broadcast Address  199.72.101.95 /27

10.  A packet with a destination IP of 199.72.101.85 255.255.255.224 goes to a router  It ANDs to come up with the NETWORK #

11.  221.17.125.46 /28  What class address? C: Only deal with the last octet!  255.255.255.240  11111111.11111111.11111111.11110000  How many bits borrowed? 4 2 4 = 16 networks  How many bits left over? 4 2 4 = 16 hosts per sub-network

12.  Based on the IP address & SM, identify…  The network address  The broadcast address  How many bits were borrowed  How many bits were left over  Is the address valid

13.  PC1 has an address of 199.15.1.40 /28. PC2 has an address of 199.15.1.50 /28. Both are connected to a switch but they cannot communicate. The switch is working normally as are the PC’s NICs and Ethernet cables. Are the hosts on the same network or separate?

14.  What’s the broadcast address for 201.78.90.0 /24?  201.78.90.255  Default SM, no subnetting  Sam’s Beef Hut uses network 215.67.106.0 & 255.255.255.240 to create subnets. How many useable hosts can be created per network?  14

15.  Which class gives you the most hosts/network? AA  Which class give you the most networks? CC  Public IP addresses must be __________.

16. 5.1.5

17.  Allows you to use part of the address for the network portion  Called partial subnetting or VLSM  CIDR allows this  Helps reduce wasted addresses  You can subnet for each unequal network  Your address is 210.1.17.64 /26 Net A needs 37 hosts Net B needs 15 hosts Net C needs 100 hosts

18.  Instead of having multiple subnet entries for each router port, CIDR uses the common bits to make ONE routing table address per port.

20. Chapter 5b