Questions tagged [ethernet]
For questions relating to Ethernet networking, as defined by the IEEE 802.3 standards.
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questions
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Connecting Render Farm to local network [on hold]
New to networking so...Looking to see if this is possible...It's also not an ideal setup so if you have recommendations on better hardware/software, I'm open.
I have a render farm with 23 computers, ...
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0answers
16 views
Calculate propagation delay for CSMA/CD [on hold]
Hi I have some trouble with this homework assignement. According to my calculation the maximum wire length would be 322 meters going by Transmission time => 2* Propagation time. Could someone confirm ...
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0answers
36 views
Help Cat6 Keystone to RJ45 [on hold]
Trying to connect one room to the router.
I have tried to use simple wiring - Cat6 with Keystone wall plate on one end
I know that a lot dont advocate this setup but since I only have one room, I ...
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0answers
21 views
Different switches showing different speeds? [on hold]
I am not network engineer. I have this problem in my home network. When I connect the cable to Linksys 2800SE switch the led indicator shows 1Gbps speed. If I connect the same cable to D-Link DGS ...
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4 views
Connect system using hardware [on hold]
How can I connect two laptops and take complete control of other machine using hardware device connected to same wifi network
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29 views
Ethernet wires in an operating room (medical) [closed]
We need to install a connection inside an operating room, the cable would appear from the roof and by side a wall. Considering the aseptic environment, we cannot use our regular wiring and encasing.
...
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28 views
How can a PC knows the maximun velocity it has available? [closed]
There are some ethernet category cables with different velocities, How can a PC knows which type it has connected? It's detected by the network adapter, it's software or it's no necessary?
Thanks!
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0answers
8 views
ARP Cache not populating fully when using unmanaged POE switch [closed]
So I am trying to set up an airgapped network with a single POE switch connected to a single laptop and a POE IP Cam.
The manual for the switch doesn’t mention the default IP address so I am ...
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2answers
70 views
What happens to undetected Ethernet errors?
The checksum used in Ethernet packets cannot 100% detect errors. If that is the case, how can I ensure that some file I have transferred from one computer to another is uncorrupted?
Thanks
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29 views
Which Ethernet Ring Protection Switching (ERPS) feature makes it so faster than RSTP/MSTP?
I want to know what makes it possible for ERPS to converge under 50 ms?
it's a hardware-specific feature that provides this fast convergence or it is about the much more efficient algorithm?
I read ...
3
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0answers
1k views
Fix Ethernet 10/100 PoE cable with 7 out of 8 wires alive [migrated]
I have a 10/100Base-T ethernet cable with PoE IEEE802.3at/af installed in my concrete walls. Unfortunately only 7 out of 8 wires are alive. Wire #6 (green) was broken during construction works and ...
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0answers
10 views
Forward traffic between 2 network interfaces in one Laptop [closed]
I have an ethernet module (a sensor but communicating via ethernet: TCP/IP) connecting to my laptop (x1 carbon). An android device (Pixel XL) in USB tethering mode connecting to my Laptop.
IP of ...
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1answer
72 views
Is PPP a useful choice for fiber connections?
I was recently thinking about how I would go about connecting two separate buildings using optical fiber cables. This is mostly for understanding how this would be done to further my mental horizon, ...
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1answer
32 views
Is it possible to propagate MAC address back to sender?
Let me first to tell me what I know, please correct me if I am wrong.
I know when Ethernet frame travels across the internet then Layer 3 data (Source and Destination IP) remains same and Layer 2 ...
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2answers
81 views
How is Ethernet a packet-switched network?
Let's say for example there is an Ethernet switch, and there are four PCs connected to this switch. PC1 and PC2 are communicating with each other, and at the same time PC3 and PC4 are also ...
0
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1answer
42 views
Is it possible to use a gigabit connection on 10/100 load balancer?
My ISP provides a connection output of 1000BASE-T.
I am trying to feed this to a load balancer device that only supports a 10/100 connection. However, the connection is not detected.
I am afraid this ...
1
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2answers
127 views
MSTP Ring - Maximum Number Of Switches?
We have inherited a ring topology with 12 switches configured with MSTP. Each switch is either 4 or 8 ports but in general most are 4 port with 2 fiber uplinks that form the ring.
We are getting a ...
0
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1answer
33 views
Inital value for the scrambler in 10GBASE-R
The standard says "There is no requirement on the initial value for the scrambler. The scrambler is run continuously on all payload bits".
I'm curious how the scrambled data can be recovered. To my ...
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34 views
Why wifi and ethernet use the same frame format from tcpdump -d output?
If I execute
tcpdump -i wlan0 tcp -d
or
tcpdump -i eth0 tcp -d
I get the same output
(000) ldh [12]
(001) jeq #0x86dd jt 2 jf 7
(002) ldb [20]
(003) jeq #0x6 ...
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1answer
68 views
Scaling fragment offset
I studied that fragment offset has 13 bits. At transport layer segmentation is done considering the the MTU at lower layers (network layer, data link layer). Ethernet format says the maximum data ...
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2answers
60 views
Can you stack Cisco 350 28P PoE switches with CAT5E or CAT6 ethernet cables?
I have four new Cisco SG 350 28P PoE switches, but no stacking cables. Can I use CAT5E or CAT6 ethernet cables to accomplish stacking them?
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2answers
32 views
Why do all leaf nodes in an E-Tree service belong in the same subnet?
I'm studying the CCNA R&S at the moment and I'm a bit confused about why E-Tree services require all leaf nodes to belong in the same subnet, despite the leaves only being able to send layer 2 ...
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2answers
73 views
Is Spanning Tree Protocol Needed?
If there are two switches connected directly together with two links is spanning tree protocol needed? please see below snippet
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1answer
206 views
Broadcast link vs. point-to-point links
What is the distinction between broadcast links and point-to-point links? In the paragraph below, the author switches between "broadcast link" and "broadcast network" which is causing my confusion..is ...
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2answers
45 views
Internet Entry Point
I am learning netwroking and would like to ask about how exactly we (as a casual user) get connected to internet and how a datacenter would do the same thing. i bet they dont use a regular modem which ...
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1answer
78 views
Sending TCP packet to the other device without connection
I think the sending packet to other device works like the following.
1. The server device listens with port. for example 80
2. The client connects to the server devices.
for example, the port of ...
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1answer
127 views
What exactly is fragment free switching?
Most commonly refered to as a compromise between store-and-forward and cut-through switching, this method involves storing the first 64 bytes of the ethernet frame in a buffer and then forwarding it. ...
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2answers
122 views
Which physical layers are part of PROFINET?
I understand that Profinet builds on Ethernet, but I am not quite sure how.
Ethernet has a lot of different standards for the physical layer, eg 10Base2 (coaxial, 10 Mbit/s), 100Base-TX (twisted ...
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2answers
104 views
Confusions regarding byte and bit ordering of Ethernet Frame
I understand the concept of Endianess regarding numbers because there the bit significance is well defined. But when applied to things like Ethernet frame or Mac address, things are so clear to me, ...
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3answers
9k views
What is “industrial ethernet”?
When a teacher introduced it to us he gave the impression that it specifically covers some Siemens technology; that it's even a Siemens trademark.
I believe the term covers something more general, ...
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1answer
85 views
Weird Wireshark protocol list (eth:ethertype:ip:data where is the “udp”?)
I am capturing incoming and outgoing WAN to LAN data at a particular host on my LAN (i.e., the one actually receiving/sending the data). Sometimes I get anomalous captured frames that are missing the ...
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0answers
26 views
Wireshark logging same error on client and server
I did some testing in Socket Programming with JAVA and analyzed my traffic with wireshark. SetUp: 1 Server running a new ServerSocket(PORT) and 1 Client running a new Socket(IP, PORT). Server and ...
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1answer
31 views
How 2 devices with different speeds communicate [duplicate]
This is an extremely basic question, But I couldn't find any answer for that.
In the scenario which I have a very old compubter that transmits 10Mbits/s and a switch that has 100Mbits ports, how ...
2
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1answer
146 views
Cisco nexus 9396PX TX output discard on 40G interface without link congestion
We have cisco nexus 9396PX with N9K-M12PQ module (12x40G Interface), We have 8x10G L3 LACP bonded connectivity with our ISP and so far so good no issue at all. but recently we migrated that LACP LAg ...
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0answers
12 views
Is pair cable always full duplex? Can it be half duplex at double the bitrate? [duplicate]
This is probably a newb question, forgive me.
For pair cable, there are two signals that can be sent: following that logic, it seems like you could have two situations: full duplex at bit rate X in ...
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0answers
27 views
Expanding network to attached building
I own a electronic design company, and recently moved into a new office space. We currently are setup in the front office, location "1" on my image. We also are converting a warehouse into an assembly ...
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3answers
2k views
Why can a packet sniffer in an Ethernet LAN obtain all packets sent over the LAN?
Why can a packet sniffer in an Ethernet LAN obtain all packets sent over the LAN?
In a limited broadcast environment, such as in many Ethernet LANs, a packet sniffer can obtain all packets sent ...
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2answers
170 views
What all fields is the FCS/CRC in the trailer of the ethernet frame calculated over?
I am unable to find the correct answer to this question all over the web. Wikipedia states The FCS value is computed as a function of the protected MAC frame fields: source and destination address, ...
2
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1answer
101 views
Using an Ethernet cable and USB Ethernet adapter at the same time?
What would happen on using an Ethernet cable connected to one network and
then plugging in another Ethernet cable but using an USB Ethernet adapter from a
different network.
Would it connect to both ...
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2answers
94 views
RS_FEC OVERHEADS ON 25GBASE-R
I'd like to estimate the effective capacity of the 25 GbE link (25GBASE-R) to transfer an Ethernet payload of a particular size when Reed-Solomon RS(528,544) forward error correction (RS-FEC) is ...
0
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1answer
114 views
How does Kismet find WIRED devices when scanning Wi-Fi? [closed]
In an effort to better secure my Wi-Fi network by finding its weaknesses and mitigating them, I have employed the use of Kismet, a well known Wi-Fi security scanning tool. When I use Kismet to scan ...
2
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2answers
43 views
Circuitry for sending and receiving bit streams in networking
To my little knowledge , I know that digital signals are transferred over continuous EM signals . At the receiver end a bit 1 is detected when the amplitude crosses a certain threshold and a bit 0 is ...
0
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1answer
70 views
Is there a MTBF related to port linking?
During a firmware upgrade, I've noticed one problem: An equipment keeps linking/unlinking on a specific port of a PowerConnect 3548(stp portfast, switchport access mode). I've contacted the local ...
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0answers
27 views
Wago 750-377 - assign IP address
I've just bought a 750-377 wago fieldbus coupler and I'm trying to assign an IP address to it through an ethernet cable that goes from the device to my computer. Is there any way to do that or do I ...
0
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2answers
50 views
what does the flag and mtu means in here
Reading some logs from my system it states
eth0: flags 4163 < up, broadcast, running, multicast> mtu
I am not sure what is the meaning of the flag here
down below I see eth1,2,3 has the same flag ...
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8answers
4k views
What do the positive and negative (+/-) transmit and receive pins mean on Ethernet cables?
So I'm trying to understand the pin layout of an Ethernet port, specifically for 8P8C which to my understanding is the most common. Of the eight pins, only four are apparently used for communication, ...
0
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1answer
223 views
What is the use of Phy and MAC chip?
Is it mandatory to have a MAC and PHY chip?
Are these two chips within a NIC CARD?
As I understand, these two chips are connected using RGMII or SGMII or xaui.
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5answers
4k views
How exactly does an Ethernet collision happen in the cable, since nodes use different circuits for Tx and Rx?
I am trying to understand how a collision occurs in Ethernet, especially when a duplex mismatch exists or when on a legacy Ethernet network two nodes transmit simultaneously.
Everyone explains the ...
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1answer
43 views
MAc address or IP address? which one gets used from my pc to router? [duplicate]
Question 1) which one is used nowadays? NAT or PAT?
Question 2) as I knew, when my pc requests some website, what happens is , the data(packets) from my pc go to router. then router makes the request ...
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0answers
10 views
What happens within a switch when a frame is moved from Device A on Switch 1 to Device B on Switch 2? [duplicate]
This might be a noob question but what happens within a switch (regarding mac tables) when a frame is moved from Device A on Switch 1 to Device B on Switch 2? I'm assuming the 2 switches are connected ...
