What is the IPv6 private address range?

What is the IPv6 private address range?

• fe80:0000:0000:0000 - feff:ffff:ffff:ffff
• ffc0:0000:0000:0000 - ffef:ffff:ffff:ffff
• fd00:0000:0000:0000 - fdff:ffff:ffff:ffff
• fec0:0000:0000:0000 - feff:ffff:ffff:ffff 

EXPLANATION

Here is a unique private IPv6 address range generated just for you (refresh page to get another one):

Prefix/L:	fd
Global ID:	2aec802d69
Subnet ID:	d701
Combined/CID:	fd2a:ec80:2d69:d701::/64
IPv6 addresses:	fd2a:ec80:2d69:d701:xxxx:xxxx:xxxx:xxxx

If you have multiple locations/sites/networks, you should assign each one a different "Subnet ID", but use the same "Global" ID for all of them.
The IPv6 address space is so huge (2¹²⁸) that everyone should be able to get a public IP address for every device they will ever own. So theoretically it shouldn't be necessary to have private IPv6 addresses like the 192.168.x.x and 10.x.x.x addresses in IPv4.

However until you can actually get an IPv6 address range from your ISP, you may want to use "private" addresses for internal networks and testing etc.
In IPv6 there is a special "Unique Unicast" IP range of fc00::/7 which should be used for this as per RFC4193.
The official definition looks like this:

| 7 bits |1| 40 bits | 16 bits | 64 bits | +--------+-+------------+-----------+----------------------------+ | Prefix |L| Global ID | Subnet ID | Interface ID | +--------+-+------------+-----------+----------------------------+

In practice such address will always start with "fd" because the 8th (L) bit must be one.
The "Global ID" and "Subnet ID" must be random to ensure uniqueness (which is what this page does).
You are free to assign addresses from the rest (Interface ID).

Please note:
A former standard proposed the use of so-called "site-local" addresses in the fec0::/10 range.
This has been deprecated (see RFC3879) and should no longer be used.

 

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What does tagging a switchport for vLAN access do?

What does tagging a switchport for vLAN access do?

• Identifies private/public network packets
• Protects against DDoS attacks
• Allows any vLANs to pass between switches
• Allows correctly labeled vLAN traffic through port 

EXPLANATION

 If you have more than one VLAN on a port (a "trunk port"), you need some way to tell which packet belongs to which VLAN on the other end. To do this you are "tagging" a packet with a VLAN tag (or VLAN header if you like). In reality a VLAN tag is inserted in the Ethernet frame.

The 802.1Q (dot1q, VLAN) tag contains a VLAN-ID and other things explained in the 802.1Q Standard. The first 16 bits contain the "Tag Protocol Identifier" (TPID) which is 8100. This also doubles as the EtherType 0x8100 for devices that don't understand VLANs.
So a "tagged" packet contains the VLAN information in the Ethernet frame while an "untagged" packet doesn't. A typical use case would be if you have one port from a router to a switch which multiple customers

In this example customer "Green" has VLAN 10 and Customer "Blue" has VLAN 20. The ports between switch and customers are "untagged" meaning for the customer the arriving packet is just a normal Ethernet packet.
The port between router and switch is configured as a trunk port so that both router and switch know which packet belongs to which customer VLAN. On that port the Ethernet frames are tagged with the 802.1Q tag.

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In networking, what does the acronym "EIGRP" stand for?

In networking, what does the acronym "EIGRP" stand for?

• Enhanced Interior Gateway Routing Protocol
• Enhanced Internet Gateway Routing Protocol
• Extra Interior Gateway Routing Protocol
• Enhanced Internet Gateway Router Protocol 

EXPLANATION

 Enhanced Interior Gateway Routing Protocol (EIGRP) is an advanced distance-vector routing protocol that is used on a computer network for automating routing decisions and configuration. The protocol was designed by Cisco Systems as a proprietary protocol, available only on Cisco routers.

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What is 1+1= ?

What is 1+1= ?

• 1
• 2
• 4
• FISH

EXPLANATION

Simple math Answer is 1+1 = 2

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Which transmission protocol uses a sequence number?

Which transmission protocol uses a sequence number?

• ICMP
• ARP
• UDP
• TCP 

EXPLANATION

The Transmission Control Protocol (TCP) is one of the main protocols of the Internet protocol suite. It originated in the initial network implementation in which it complemented the Internet Protocol (IP). Therefore, the entire suite is commonly referred to as TCP/IP. TCP provides reliable, ordered, and error-checked delivery of a stream of octets (bytes) between applications running on hosts communicating via an IP network. Major internet applications such as the World Wide Web, email, remote administration, and file transfer rely on TCP. Applications that do not require reliable data stream service may use the User Datagram Protocol (UDP), which provides a connectionless datagram service that emphasizes reduced latency over reliability.

Reliable transmission. TCP uses a sequence number to identify each byte of data.

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For machines running Hyper-V, which of the following is the first software to load at boot time?

For machines running Hyper-V, which of the following is the first software to load at boot time?

• The hypervisor
• Windows OS
• Both Windows OS and the hypervisor simultaneously
• Virtual machines and applications 

EXPLANATION

 A hypervisor or virtual machine monitor (VMM) is computer software, firmware or hardware that creates and runs virtual machines. A computer on which a hypervisor runs one or more virtual machines is called a host machine, and each virtual machine is called a guest machine.

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The Live Migration process with Hyper-V refers to which of the following?

The Live Migration process with Hyper-V refers to which of the following?

• Moving VMs from one physical host to another
• Reassigning user rights to different virtual machines
• Moving physical servers to a different part of a data centre
• Upgrading the server OS on a host machine 

EXPLANATION

Live migration refers to the process of moving a running virtual machine or application between different physical machines without disconnecting the client or application. Memory, storage, and network connectivity of the virtual machine are transferred from the original guest machine to the destination.

 
Hyper-V live migration is a Microsoft Hyper-V feature that allows administrators to move virtual machines (VMs) between clustered hosts without noticeable service interruption.

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