For questions relating to Ethernet networking, as defined by the IEEE 802.3 standards.
0
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0answers
15 views
I can connect to the second router but no internet? [on hold]
Before I ask my initial question, I'll explain the setup and background.
I am helping a business fix their internet after a camper reported that the internet had gone out. I went to check, and sure ...
-1
votes
3answers
40 views
Why do we need an ethernet MAC address? [duplicate]
Don't think it's a duplicate. I've searched really many articles and couldn't find the satisfying answer.
I understand :
how ARP works
MAC address is an unique address for each NIC
IP is network ...
0
votes
1answer
33 views
Setting MAC source address to broadcast
How would a network behave if one were to set the source address of an Ethernet frame to the broadcast address FF:FF:FF:FF:FF:FF?
Obviously, one would have to manually alter the relevant field in the ...
0
votes
2answers
35 views
What Are LAN technologies?
I know about different LAN topologies(like star, bus, ring,...) and that Ethernet is one of the ways to practically implement wired LANs. I wonder what other technologies exist to make LANs? And, is ...
0
votes
3answers
124 views
Can Ethernet use fiber optic cables?
I am new to networking, know about Ethernet and that Ethernet cables exist to make a wired networks. I also know about fiber optic cables which have a glass like material inside and transmit light ...
1
vote
0answers
8 views
How an MKA key server decides if it shall use MACSec and how it announce that?
According to IEEE 802.1X-2010 the standard for defining MACSec Key agreement protocol Clause 9.6, that's how the key-server decides to use MACSec or no.
Each participant advertises whether it is ...
1
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0answers
19 views
How are required Keys inside MACSec Key agreement protocol (MKA) generated?
I am trying to wrap my head around MACSec Key agreement protocol (MKA) and its relation with MACSec and other protocols. So bear with me.
To my understanding in order to MACSec to work, all nodes ...
2
votes
1answer
56 views
Packet vs Circuit switching
I have a 1Mb/s link each user uses 100Kb/s when active.
With 10 user active 10% of the time, I can have 10 users in a circuit switched environment. Packet switching with 35 users, probability > 10 ...
2
votes
1answer
49 views
End-to-End delay
I’m working through questions from computer networking top down approach and was hoping to get some clarity on the end-to-end delay calculation. At this stage we are not considering processing, ...
5
votes
4answers
646 views
Why is the Ethernet Connection Symmetric?
I know that cable connection (DSL) is asymmetric, there is a certain bandwidth on the channel, and for a better user experience, they allocate a bigger portion to the downstream. I suppose Ethernet ...
2
votes
2answers
75 views
Effect of large amount of bare ethernet pairs on network performance
I have a client who has been experiencing a significant amount of performance issues in regards to their telemarketing floor. On my initial assessment, I found that where the ethernet is punched down, ...
1
vote
1answer
74 views
Improve ping speed (lower up ping time) [closed]
In normal network with Cisco 3650 (1Gbps) and Linux base servers, the ping time is between 0.150ms to 0.250ms. (I also mean using ping or ICMP is to refer to all protocols)
I want to know is there ...
4
votes
1answer
516 views
Do we send ack frames in ethernet? if not then how does a router know if its neighbors are down or not?
So first off, do ethernet sends ack frames or not?
if it doesn't : then how does a router know whether its neighbors are down or not?
if it does : then is it cumulative ack with an ack timer or one ...
10
votes
2answers
3k views
Is the MTU of Ethernet still 1500 Bytes?
So basically do the modern routers in the internet still use 1500 as the MTU of Ethernet? or the 1500 Byte was for the old days?
What I'm asking here is what is the MTU of Ethernet in modern Networks?...
2
votes
2answers
115 views
Does Ethernet still use CSMA/CD?
So considering that CSMA/CD is for detecting collisions, mostly in a bus scenario with a lot of stations, then is CSMA/CD still used?
Because right now most of the connections are point to point (for ...
0
votes
1answer
32 views
Part of ethernet crc showing up in tcpdump
I am testing the ethernet transmission on my Digilent Nexus4 DDR FPGA. I created a really simple packet with a broadcast destination address and some made up ethernet type. Here is the packet as ...
3
votes
1answer
153 views
Dot1q tags, sub-interfaces
Please consider dot1q frames tagged 100 circulating on a LAN (VLAN 100).
To go out onto the Internet, frames have to go through a PPPoE sub-interface which is configured as below:
interface ...
0
votes
1answer
21 views
How to show all data (bitstream with preamble, SFD) on Ubuntu with an Intel Ethernet Interface?
On my PC I have an Intel Ethernet Connection I217-LM with e1000e driver.
If I receive packets in Wireshark or any libpcap based tool, the received ethernet frames start with Ethernet II frame and end ...
5
votes
5answers
2k views
Does a Layer 3 switch become a Layer 4 device when telnetting?
In order to Telnet to a switch (Layer 2) we create an SVI, thus a layer 3 point of contact is made. The switch inspects each packet sent from the remote client and responds to it so that it gets ...
2
votes
1answer
37 views
Ethernet's frame format, length or EtherType?
Ethernet defines a 2 byte header for the payload's length in its frame format.
This header has an ambiguous meaning:
if smaller than or equal to 1500 it represents the payload length.
if ...
1
vote
0answers
18 views
SSH into device attached to another router [closed]
I saw this questionwhich looks kind of related, but I'm not sure as the answers are too confusing.
Basically, I want to SSH into my Raspberry Pi from my laptop. Eventually I want to have the Pi ...
-1
votes
1answer
48 views
What is Ether? is it the same meaning with Ethernet?
What is Ether? is it the same meaning with Ethernet?
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votes
1answer
41 views
IP/Device Question
I am very new to this field and I want to ask a quick question about IP/Device HTTPS.
When we type in the IP address of the device (cisco switch, router, firewall, etc), we can access to the web ...
4
votes
2answers
191 views
What is the springing mechanism for on the top of this transceiver module?
Some Ethernet SFP modules have them, some do not. What is the yellow springing mechanism and the attached metal wire meant for?
1
vote
1answer
36 views
Calculating buffer capacity
The serialization delay is the amount of time it takes to forward bits out of an interface. A 1 gigabit per second interface can send 1 billion bits per second. One billion bits per second equates to ...
2
votes
3answers
551 views
Is Ethernet a broadcast or point-to-point protocol?
Theoretically speaking, as far as I know Ethernet was developed to be used as a broadcasting protocol and technology. I guess nowadays it is not being used this way. Since ALL the examples I see refer ...
0
votes
2answers
106 views
Access a subnet through another network
We have some devices connected together through a switch. We need to access them through another network, but because of IP counts limitation we cant get IP from that network.
Q: How to access my ...
-1
votes
2answers
36 views
Can a switch segregate traffic that is before the switch from after the switch?
Per the question, Lets try to clarify a bit. Can a switch that has a router connected to it, segregate traffic (using a VLAN) from traffic that is part of the modem/router the switch is connected to?
...
1
vote
1answer
36 views
Initial connection to WI-FI
My question is what is happening during the initial connection to a wireless network , is there an Ethernet connection first and then DHCP or something else is happening before the device receive an ...
0
votes
1answer
31 views
Compatibility of CentreCom Transceiver 210TS 10BaseT Ethernet with modern Ethernet
I have two old legacy system communicating each other using CentreCom 210TS 10BaseT Ethernet Transceiver. The Transceivers are connected to AUI port of system. SQE test is disable on both transceiver. ...
3
votes
1answer
64 views
What is a fractional port?
I was reading a product sheet about a Metro-Ethernet backhaul service which mentions, which is described as a mechanism to connect two datacentres within the same region (ie, city) via point-to-point ...
3
votes
2answers
367 views
Is there 64k range VLAN support?
All i have learnt and understood so far about VLAN is - we can create a max of 4k VLANs (subjected to platform capability). However, as per the protocol 802.1Q there is only 12 bits kept for ...
4
votes
1answer
454 views
How do data packets travel without merging?
I have been very interested in networking for quite a while, and I have been wondering this question. I've been thinking about this in complete binary, meaning how does a 0 of a data packet not get ...
-1
votes
1answer
176 views
What is the EtherType of a BPDU frame sent by a switch which runs Spanning Tree Protocol
I want to know what is the EtherType field of a BPDU frame in various versions and variants of the Spanning Tree Protocol.
2
votes
2answers
207 views
Are normal packets ever combined into jumbo packets?
Do routers ever combine multiple small frames into a jumbo frame then split them up again on the other end? I know that most of the time it wouldn't make sense to do because you would add latency by ...
3
votes
2answers
68 views
Any reason to use hubs?
Given that hubs are essentially the same as switches, as far as I know, except they share bandwidth between all connected devices, while switches do not, resulting in faster connections. I am simply ...
0
votes
1answer
61 views
How might I test layer2 latency over ethernet without a target IP address? [closed]
Is there a way, via standard ethernet layer2 protocols, to test latency to a device without using it's IP address?
Background:
I have a fibre "box" provided by my ISP physically connected to my ...
4
votes
1answer
103 views
EHWIC-1GE-SFP for Cisco 1941
I was able to configure the interface but only the GE port is working, not the SFP port.
Did I miss something?
2
votes
1answer
210 views
Verifying 802.3 auto negotiation
This is my setup:
The Problem
The end point, ethernet device B, is powered by the power injector but receives no data. Everything is connected using CAT5 cable.
Ethernet device A signifies a GB/s ...
4
votes
5answers
534 views
Why can't two hosts (in two different logical networks) connected to each other through cross-over cable communicate?
Let us say, i have two computers (hosts) A and B. Where A has been assigned an IP address of 192.168.1.10/24 and host B has been assigned an IP address of 192.168.2.11/24.
And both of them has been ...
4
votes
1answer
682 views
LACP and how to configure switches correctly
I want to set up a fast network and am considering options.
I want a backbone switch that connects all my switches together. I can see options for SFP / SFP+ ports. Some SFP ports are 1 or 2 Gb from ...
4
votes
2answers
954 views
How does Ethernet Switch ensures the validity of the MAC address table?
Let us say I have switch S with 4 ports, PA, PB, PC, and PD, to which I have connected 4 hosts, A, B, C and D with the MAC addresses AA:AA:AA:AA:AA:AA, BB:BB:BB:BB:BB:BB, CC:CC:CC:CC:CC:CC and DD:DD:...
5
votes
3answers
1k views
How is data sent from multiple different sources (computers) to the same destination host (computer) on a local network is handled by switch?
Let us say I have switch S, to which I have connected 4 hosts (A, B, C and D).
Now let us say hosts A and B both want to send a series of data to the same host D at the same time. So here, A and B are ...
1
vote
2answers
50 views
How to debug an unstable connection in a P2P configuration
I have a setup where I have two computers connected to each other (C1 and C2). Both have a static IP and they know each others IP. C2 sends UDP packets to C1 and C1 receives and logs them.
Seems ...
2
votes
1answer
38 views
Cisco Router 1002f Sfp Port to Cisco swtich c3750 gigabit port
an anyone please instruct me how to connectCcisco router 1002f SFP ports to gigabit ports?
I have an RJ45 port on switch side and an SFP port on router side. I like to use switch as dump switch. I ...
3
votes
3answers
343 views
What is likely to occur with the frames addressed to x, if x is disconnected from the switch. then reconnected on another link?
I don't see how this could be a problem, as the switch table would remember the destination MAC address.
My teacher says this is a problem and that the switch would need to reconfigure.
could you ...
3
votes
1answer
60 views
Does an ethernet checksum include padding bits?
For ethernet II (aka ethernet DIX) frames that are padded to contain 64 bytes total, is the checksum in the last 4 bytes computed with the padding bits as input?
1
vote
1answer
87 views
What's meant by AUI & MAU in ethernet networking?
The questions is so clear, what's meant by AUI (Attachment unit interface ) & MAU (Medium attachment unit) in the scope of Ethernet ?
Background : I've recently started to work as software ...
1
vote
2answers
65 views
Why are WLAN packages translated to Ethernet packages by Wireshark?
When using Wireshark on my MacBook, I see all my packages wrapped inside Ethernet II frames, although I'm connected wirelessly, which I already figured must be because they are translated from 802.11 ...
1
vote
1answer
120 views
Bypass Router to connect to modem
The network has 2 subnets:
i) 192.168.1.x
ii) 192.168.100.x
The telecom optical modem sits at 192.168.1.1
A cisco router and windows server are present on the network.
DHCP and ...
