jcbermu
  • Member for 6 years, 6 months
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How does a packet get corrupted in a network?
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21 votes

Packets are long streams of binary numbers (zeros and ones). The zeros and ones are usually changes of an electric signal, specifically voltage changes. To simplify, suppose that 0 is 0 volts and 1 ...

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Where can I use the IPv6 documentation prefix
20 votes

The IPv6 documentation prefix (2001:db8:::/32) must be used ONLY for documentation purposes. It means written examples, diagrams, PPT presentations, Textbook explanations, etc. This range shouldn't ...

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What is SNR Margin and Line Attenuation?
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18 votes

The SNR margin is the Signal to Noise Ratio margin. Signal to Noise Ratio is the relation between the data signal level and the noise level. Even the most perfect cable absorbs some noise. This "...

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What is the reason for T568A and T568B termination?
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13 votes

UTP cables used in the 586 standard inherited their color code from the 25 pair color code developed by AT&T for cabling used in telecommunication purposes. The following table shows the ...

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What do packets look like?
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13 votes

To transmit data you need a media (copper or optical fiber, for example) and each media has its own set of features than make it usable for data transmission. For example copper is a good electrical ...

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How is data sent from multiple different sources (computers) to the same destination host (computer) on a local network is handled by switch?
12 votes

Switches forward all packets it receives to the best of its ability. If is unable to send a packet immediately, the packet is queued in a buffer and if the queue is full, the packet is dropped. ...

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is there a difference between Latency and speed ?
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11 votes

You can have high speed, but if you have to go through a long distance then you have also high latency. Let's use Los Angeles and London to understand this: The distance from Los Angeles to London ...

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Ping a private IP address in another network
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10 votes

A PC in a private IP range can't be acccesed from the public internet. Devices in private range connecting to internet use a proxy or router/NAT device that replaces the local source IP for a single ...

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What is the meaning of streamlined ipv6 header?
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10 votes

IPv4 has a lot of fields (14) in the header: Version IHL: Internet Header Length. DSCP: Type of Service. ECN: Explicit Congestion Notification. Total Length: Length of entire IP Packet. ...

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Maximum number of Subnets
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9 votes

A /23 block contains 512 addresses. 2^(32-23)=512 You can use them to make any number of subnets that you want. For example: 2 subnets of 256 addresses (254 hosts, 1 for subnet and one for broadcast)...

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Traceroute UDP port question
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8 votes

To understand the mechanism, let's see it with an example: I issue a traceroute to 44.12.44.1 from my PC My PC sends 3 UDP datagrams to 44.12.44.1 with TLL=1 and port=33434 Inmediately sends 3 UDP ...

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How will be the ARP Request (Unicast/Broadcast) if Subnet Mask is Unknown
7 votes

A device only knows its own subnet mask, and it helps the device to calculate which network it belongs to. Everything outside the network must go through the default gateway and everything in the ...

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What is "Twisted pair with loading" cable?
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7 votes

A twisted pair cable with loading is a cable that has added inductance. It is a cable used for voice lines. A long span of twisted pair wires acquires capacitance and that's the case with voice ...

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Is a unique TCP/UDP port assigned to a user?
6 votes

Think of ports as doors. Your PC has a lot of doors and the server also. A web server has the door 80 open, so if a PC acting as a client wants to connect to the web server, then: 1- The PC opens ...

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Difference between data link and transport layer error detection?
6 votes

Link layer Error Detection: A method to verify the integrity of frames when they are transmited over the media. The receiving side can verify if the received frame has been damaged on transit. If link ...

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IP Address vs MAC Address, how does that really work together illustration
6 votes

IP is a layer 3 protocol. It doesn't know anything about the physical media, it means that IP can travel through any media (for example: fiber optic, copper cable, air, etc). IP relies on a layer ...

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What is the minimum diameter for Power over Ethernet?
6 votes

As I know the main problem of transporting power over ethernet cables is temperature rise and resistance. 802.3af defines the max power as 12.95 W and max current as 350 mA over 2 pairs. 802.3at ...

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Why and when do we use digit '9' before making an outbound call?
Accepted answer
5 votes

In traditional public telephony in USA exists the North American Numbering Plan that defines this: NPA (Numbering plan Area Code) 3 digits NXX (Central Office) 3 digits xxxx (Subscriber Number) 4 ...

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Interfaces named with `ge` represent what?
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5 votes

I guess you're asking about JunOS, the Operating System of Juniper for their hardware. ge means Gigabit Ethernet. This a list of ethernet interfaces and names used in JunOS: ae— Aggregated Ethernet ...

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How does routing work across different networks when using a dedicated switch?
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5 votes

The traffic will go through the router unless your switch is a Layer 3 switch, and you configure it to make a direct routing from PC to Server. However to achieve that you will need to put the PC and ...

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How does the switch learn the mac addresses when it's connected to a router?
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5 votes

Each router replaces the Original source MAC address with the MAC adddress of the interface where the packet is going out of the router. (in this case, the packet comes in through the red interface ...

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10baseT and 10baseFX difference
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5 votes

10BaseT and 10BaseFx are standards of connectivity for Ethernet. 10BaseT defines the use of twisted pair cabling (UTP / STP) for Ethernet, that includes cable features, male (in cable) and female (in ...

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Explain what is Virtual LAN
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5 votes

A LAN is a group of devices connected to the same network that can commuicate among them. A virtual LAN is a group of devices that using a predefined tag in the ethernet frames can communicate among ...

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What are the collision domain reducing devices?
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4 votes

A collision is the moment when two or more frames from two or more different devices are in the network at the same time. Collisions are a feature of networks, as ethernet, that were designed to share ...

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IP address classification?
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4 votes

Forget about classes. They were overruled by CIDR (Classless Inter-Domain Routing) in 1993. The router vendors usually put the address of the device in the range 192.168.X.X It is configured in that ...

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Choosing a routing protocol
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4 votes

To choose a routing protocol you should consider these topics: Configuration: How easy is to configure and troubleshoot the protocol. Efficiency: How fast it converges? How much bandwith it uses? ...

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full utilization of bandwidth and its physical significance
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4 votes

Suppose this scenario: The sender and the receiver share a 1 Mbps bandwith media. If the sender needs to send a file of 2 Mbit, in an ideal world it will take 2 seconds using the full bandwith. ...

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Why does throughput (consumed BW) increase when the packet error rate is increased in the TCP?
Accepted answer
4 votes

Errors in transmission are detected in TCP layer. The receiving TCP layer discards the damaged segment, forcing the sender to sent the segment again.

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P2P Applications and ISPs
Accepted answer
4 votes

Suppose the typical client-server connection, for example watching a YouTube video or browsing the web. When you watch a video or do web browsing the downstream is highly used, but the upstream is ...

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Spanning Tree protocol question
Accepted answer
4 votes

The root bridge sends BPDU's to know if the network has changed and to inform other bridges in case of change. The frequency of those BPDU's is determined by a setting called hello time that can be ...

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