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What does the naming convention for Ethernet standards mean: 1000BASE-T, BASE-TX, BASE-SX, etc.? What is the meaning of the components of the name?

I understand the number in the naming convention. The number represents how many Megabits per second can the standard support. However, I do not understand the rest of the naming convention. What do "BASE," "T," "X," etc. mean? Can someone explain…
yoyo_fun
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Is Nexus 7000 series line card "OIR" impact-free?

I have read many data sheets on the Nexus 7000 series and it's cards purporting to be capable of OIR (Online Insertion and Removal). However I have never needed to replace/reseat/add any Nexus line cards since I walked into this Nexus deployment two…
Brett Lykins
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14
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Should a router use SLAAC for IPv6 address assignment?

I am a little confused by the following 2 RFCs relating to IPv6: RFC 4862 (IPv6 Stateless Address Autoconfiguration) RFC 7084 (IPv6 CE Router Requirements) RFC 4862 states: The autoconfiguration process specified in this document applies only to…
banjaxed
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Why do I need a crossover cable to connect devices of the same type?

I know that a crossover cable should be used to directly connect devices of the same type and patch cable is used to connect devices of different types. But I never understood why is it so exactly? Why does such design has been chosen? Does the…
syntagma
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14
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2 answers

Broadcasting wifi packets without a network

I have a question about Wifi, I couldn't find the answer anywhere. Is it possible to send a packet over wifi without having joined any kind of network (ad-hoc or not)? I would like to be able to send packets in the air without joining a network.…
Noé Malzieu
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14
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4 answers

Possible (bit) patterns of a netmask

Given a prefix Y, it's easy to calculate the corresponding netmask: Put Y times a set bit, and then fill up "to the right" with zeros until one has 32 bits (IPv4) in total. Example: Prefix 24, thus netmask 11111111 11111111 11111111 00000000 or…
Daniel Jour
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14
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7 answers

Full-duplex with two antennas

It is said that wireless is a half-duplex medium. "Dual-band" stations are now common, with one antenna in the 2.4 GHz band, and the other in the 5GHz band. Suppose now we have stations with both antennas in, say, the 5GHz band, but on different…
T. Webster
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BGP regular expression .+_.+_.+_.+_.+_.+_.+_.+_.+_.+_.+_.+

could anyone tell me what ip as-path access-list 100 deny .+_.+_.+_.+_.+_.+_.+_.+_.+_.+_.+_.+ stands for?! I searched over the internet for the meaning of this regular expression, but I was unable to find any info.
ipermo
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How does a switch learn a MAC address not in its lookup table?

I have a relatively dumb question. Suppose the Switch just started, and it received a frame that contains a destination MAC address for a network device not in its MAC addresses table. What happens then? Does it broadcast (MAC address…
user24308
14
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1 answer

What happened to IPv5?

I hear/read much about IPv4 and IPv6 and nothing about IPv5. Where did it get lost in the discussion?
Waldemar Gałęzinowski
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14
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2 answers

Does the source MAC address of a frame change when it passes through several switches?

If PC1 sends an Ethernet frame to Switch1 which forwards the frame to Switch2 which in turn forwards the frame to PC2, does any decapsulation happen that changes the source MAC address?
Rana Mallah
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In what mode does the 2960-S IOS prompt ends with a colon ":"

QUESTION For a Cisco 2960-S switch, when connecting on the console port, normally the prompt is: SwitchName> then you issue an enable command and end-up with a prompt like: SwitchName# However, I stumbled to diagnostic a switch which was…
Philibert Perusse
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14
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1 answer

Four layer-2 addresses in 802.11 frame header

I am new to wireless LAN. I see that it has four addresses in the frame header. In case of a Wired Ethernet, there are only two MAC addresses, the source and the destination (which is essentially the address of the next hop). But in case of wireless…
Ankur Bhatia
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14
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6 answers

What happens when the ARP cache overflows?

In at least one implementation there is a hard limit on the capacity of the ARP table. What happens when the ARP cache is full and a packet is offered with a destination (or next-hop) that isn't cached? What happens under the hood, and what is the…
neirbowj
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STP blocking port selection

I want to make sure I'm understanding how this works. Specifically the term "Sending Port ID" has me very confused. Consider this diagram, I want to make sure I have root port selection figured out: The switch on top is the root and all settings…
red888
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