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@@ -251,7 +251,7 @@ image::Classes_of_IPv4_Networks.png[Classes of IPv4 Networks,float="center"]
* *Subnetting*
** IPv4 Subnetting is the process to sub divide the larger network into smaller, less wastefull, subnets. For example if we have a given network of 192.168.10.128/25, which there are a total of 128 IPs (128-255), with the first IP assigned to the network address (128) and the last to the broadcast address (255). That leaves 126 IPs to be assigned to one network. If we needed to support two networks, we would need to subnet our original network into something smaller. We do this by borrowing a bit from the host side for the network side.
** IPv4 Subnetting is the process to sub divide the larger network into smaller, less wasteful, subnets. For example if we have a given network of 192.168.10.128/25, which there are a total of 128 IPs (128-255), with the first IP assigned to the network address (128) and the last to the broadcast address (255). That leaves 126 IPs to be assigned to one network. If we needed to support two networks, we would need to subnet our original network into something smaller. We do this by borrowing a bit from the host side for the network side.
** The CIDR, /25 in this case, identifies 25 network bits are cut "ON" (1) to produce a subnet mask of 255.255.255.128 leaving 7 host bits or "OFF" bits (0).
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@@ -718,7 +718,7 @@ Instructor Notes
==== 2.1.1.5 Explain OS Fingerprinting with TTL
OS fingerprinting is the process of analyze the TTL fields on a header packet to make an educated guess at which operating system sent the packet by your TTL maximum hops. Different systems can have varing TTLs that can help to identify them on the network, some of the systems are listed in the chart.
OS fingerprinting is the process of analyzing the TTL fields on a header packet to make an educated guess at which operating system sent the packet by your TTL maximum hops. Different systems can have varing TTLs that can help to identify them on the network, some of the systems are listed in the chart.
This will be covered more indepth in Lesson 6 Network Analysis.
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@@ -1087,7 +1087,7 @@ Instructor Notes
** IPv6 addresses are 128 bits in length and will support up to 340 undecillian addresses.
*** 64-bit Prefix (4 hextets) - Generally this is the network portion of the address.
**** Organizations asigned a 48-bit Prefix by IANA.
**** Organizations assigned a 48-bit Prefix by IANA.
**** Last 16-bits of prefix is used for subnetting (allows upto 65,536 subnets).
*** 64-bit Interface ID (4 hextets) - Generally this is the host portion of the address.
**** Allows for 2^64^ hosts or 18,446,744,073,709,551,616 (eighteen quintillion, four hundred forty-six quadrillion, seven hundred forty-four trillion, seventy-three billion, seven hundred nine million, five hundred fifty-one thousand, six hundred sixteen).
