VLSM Example
Let’s say I want to subnet my 192.168.1.0 network in the most efficient
way, let’s take another look at the requirements I just showed you:
•One subnet for 12 hosts.
•One subnet for 44 hosts.
•One subnet for 2 hosts.
•One subnet for 24 hosts.
What kind of subnets would we need to fit in these hosts? Let’s see:
•12 hosts, the smallest subnet would be a block of 16.
•44 hosts, the smallest subnet would be a block of 64.
•2 hosts, the smallest subnet would be a block of 4.
•24 hosts, the smallest subnet would be a block of 32.
19.2
Table 19.3 Addresses for private networks
19.3
Figure 19.10 A NAT implementation
19.4
Figure 19.11 Addresses in a NAT
19.5
Figure 19.12 NAT address translation
19.6
Table 19.4 Five-column translation table
19.7
Figure 19.13 An ISP and NAT
19.8
19-2 IPv6 ADDRESSES
Despite all short-term solutions, address depletion is
still a long-term problem for the Internet. This and
other problems in the IP protocol itself have been the
motivation for IPv6.
Topics discussed in this section:
Structure
Address Space
19.9
Note
An IPv6 address is 128 bits long.
19.10
Figure 19.14 IPv6 address in binary and hexadecimal colon notation
19.11
Figure 19.15 Abbreviated IPv6 addresses
19.12
Example 19.11
Expand the address 0:15::1:12:1213 to its original.
Solution
We first need to align the left side of the double colon to
the left of the original pattern and the right side of the
double colon to the right of the original pattern to find
how many 0s we need to replace the double colon.
This means that the original address is.
19.13
Figure 20.4 Position of IPv4 in TCP/IP protocol suite
20.14
Figure 20.5 IPv4 datagram format
20.15
Figure 20.6 Service type or differentiated services
20.16
Note
The precedence subfield was part of version 4, but never
used.
20.17
Table 20.1 Types of service
20.18
Table 20.2 Default types of service
20.19
Table 20.3 Values for codepoints
20.20
Note
The total length field defines the total length of the datagram
including the header.
Figure 20.7 Encapsulation of a small datagram in an Ethernet frame
Figure 20.8 Protocol field and encapsulated data
Table 20.4 Protocol values