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1500 questions
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3 answers

Why can't devices in different subnets talk with each other?

I know that the layer 2 doesn't understand IP, and the broadcast domain is same. Why can't devices talk, how does it happen?
Nina
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Cisco 1260 AP no longer responds to ping, ssh after upgrade to latest 15.x firmware

I have a 1260 AP that I upgraded this morning. Prior to the upgrade, the system permitted ssh and would respond to pings on the network, however now it does not respond. I hooked up a serial cable and surfing around the config I can't seem to find…
Peter Grace
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1 answer

Why does source port and destination port differ, in my network communications?

I just knew by theory how two host communicate through a port and a protocol, and i always thought that they must be using the same port number aat both ends to communicate, but looking at the network traffic(using iftop on unix) on my computer…
Xsmael
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1 answer

PPPoE vs L2TP protocols

I am trying to find differences between PPPoE and L2TP.Both are tunneling protocols. When to use what? thanks, GL
user2148707
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8
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3 answers

How to find the MAC address of a router?

I'm trying to figure out the MAC address of my router. This picture is of using the command ipconfig: This picture is of using the arp -a command: I see it says my IPv4 address is 192.168.1.114, so I go down to it in the arp -a command. However,…
Yoshi24517
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2 answers

What exactly is IPoE?

I am familiar with PPPoE but getting confused with the term IPoE. Is this same as usual ethernet with DHCP server? Does this have any auth built-in? How do I get authenticated? What can a client connect? I did some googling but the information I got…
user2148707
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1 answer

What is the meaning of streamlined ipv6 header?

I don't understand what it is meant for "streamlined ipv6 header"? Could you please provide an example?
gaetano
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8
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3 answers

Does a switch understand packets? If yes, what is the frame terminology for?

I was a little confused between packet and frame. The confusion was based on, if a switch is a layer 2 device, how does it reads a packet from a layer 3 device, and where is the 'frame' thing which is understandable to a switch (or layer 2…
Taha
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8
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2 answers

How to make CLI enter new line automatically

I would like to know the command to configure CLI on cisco equipment to make the cursor move to the new line right away after it showed the message. So for example: Router# Router# *00:00:00: Interface Ethernet0 chaged state to up.Link blablalba*…
user2965743
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1 answer

Will WireShark assume packets are DUP or Retransmitted?

I have a SPAN on two different switch ports which are going to the same sniffer. Host A's connecting port is SPANed, and host B's connecting port is SPANed as well. Because it's a router on a stick type of configuration, I was hoping that during a…
LIK
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8
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1 answer

ASA5550 Error: assertion "_vf_mode_init" failed: file "vf_api.c", line 99

I pulled an old ASA5550 off the shelf, which had 8.4(2) loaded on it. When I tried to boot it, I got the following error... ----------------------------------------------- Traceback output aborted. Flushing first exception frame: Abort: Assert…
Mike Pennington
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8
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5 answers

What is the difference between broadcasting and flooding?

In the Open Shortest Path First routing algorithm, the information about connected links is "flooded" throughout the network. How is flooding different from broadcasting?
Himanshu Patel
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8
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3 answers

When exactly is ARP protocol is used

I am a quite a beginner in network engineering so please be nice. I am not sure I understand how ARP protocol works in some situation. For example, if we have following problem: ARP cache is empty host1 (source) --> router1 (default) router1…
MyNameIsNemo
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2 answers

Aggregate bandwidth of a gigabit switch

This one might be the dumber question ever asked in this place, but here it is: If I have 20 machines, all equipped with gigabit ethernet NICs, all connected to a gigabit switch, is the maximum volume of data going through the switch per second…
arnaud briche
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8
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1 answer

Migrating from STP short mode to long mode?

It was decided recently to migrate a large campus network from the short mode STP costs (16-bit) to the long mode STP costs (32-bit). I have clearly found it documented that this needs to be a "universal" configuration in that all switches need to…
YLearn
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