Questions tagged [ethernet]
For questions relating to Ethernet networking, as defined by the IEEE 802.3 standards.
863
questions
0
votes
0
answers
11
views
Data diode and seamless transfert [closed]
I've made a data diode to protect access between a critical network and the Internet.
It's composed of two Raspberry Pi and an optocoupler.
The tutorial can be found here (not made by me): https://...
- 101
0
votes
1
answer
47
views
iSCSI silent data corruption
I came across an interesting table with estimations of silent data corruption rate for different interfaces. SAS shows the best result when the built-in integrity control (DIF) is enabled:
Interface
...
- 103
0
votes
2
answers
67
views
100Mbps embedded device on a GbE network.. can I use MII?
Newcomer to Networking. I would like to connect an embedded device to an existing Fibre Gigabit LAN. The device would source and sink very little data so I am considering my choices.
A ...
- 1
0
votes
1
answer
28
views
Slim Ethernet 28AWG Length Limitation question for IDFs
anyone have experience with the slim ethernet cabling? I see a lot of atricles stating they are limited to around 30ft. Does this footage include the in-wall cat6 run from Patch panel to Desk drop? ...
0
votes
1
answer
24
views
Confusion between MDI and MII
Media Dependent Interface
Media Independent Interface
My understanding is 2. is an interface between PHY chip and MAC block on the board. PHY chip can be on the board, or detachable. It is rather PHY ...
- 105
0
votes
1
answer
44
views
Network connection into a Faraday cage
I have a situation where I need to put a WiFi-only IoT device inside a radiation-shielded space in which the facility WiFi doesn't work. (Even outside the shielded space the WiFi barely works, due, I ...
- 101
0
votes
1
answer
77
views
Is it possible to establish communication using just an ethernet cable?
I have two linux systems, server and client, whose both ethernet port has VLAN tagging(preconfigured IP address and same subnet), and connected with a common ethernet cable (no router or network ...
- 1
0
votes
2
answers
90
views
Connecting L3 and L2 switches with VLAN settings
I have 1 L3 switch with
Static ip - 192.168.0.252
Two L2 switches
Switch A - 192.168.0.250
Switch B - 192.168.0.251
I have created VLANs in L3 switches with 192.168.1.1 and 192.168.2.2 ips abd set it ...
- 101
0
votes
2
answers
60
views
Degradation of signal quality as a function of cat 6 cable length
I would like to make a run of cat 6 ethernet cable between 2 dwellings, underground. It appears I may need just a little over the maximum length for 1 Gbps (100 meters), maybe 110 meters or so. ...
- 103
7
votes
9
answers
4k
views
Why can I send 127.0.0.1 to 127.0.0.0 on my network?
We have a product that runs over IP. This product comes in two halves that are supposed to be connected directly to each other over Cat 5e. All this works fine.
For reasons that are not important, we ...
0
votes
0
answers
43
views
I can no longer access my Dell EMC N1124T-on through its GUI interface
We configured and set up our Dell EMC with a Putty interface first and went through the Set up wizard and gave it a static IP. Then joined it to our network and Deployed it into our IDF. Accessed it ...
- 1
1
vote
2
answers
73
views
What components of a network switch qualify as ASICs?
While studying for CCNA, I came across the information that in a network device, say a switch, the CPU is responsible for the control and management planes work, while the actual data forwarding is ...
- 139
1
vote
2
answers
104
views
What is the loopback Ethertype?
IANA's list of IEEE 802 Ethertypes includes an entry for Loopback (0x9000). However, I cannot find any specification detailing exactly how this is implemented. Do frames sent with Ethertype 0x9000 ...
- 113
2
votes
2
answers
253
views
POE injector to extend the number of devices
I have a networking problem. I have a network that runs of a POE switch that is routed to a relatively deep chain of POE powered switches that also passthrough POE. The problem becomes that the load ...
- 135
0
votes
0
answers
91
views
Why are the pins in this RJ45 port not all identical?
As shown on the picture below, the pins on these Ethernet ports are not all the same.
It looks like pin 3, 5, 7 and 8 (or 1, 2, 4 and 6?) are elevated in order to make contact, but not the others.
I'm ...
- 101
0
votes
1
answer
108
views
Which Ethernet cable should l use to connect two office buildings?
I am an extreme newbie in real networking. I have developed an application for our internal office management which is to be installed on 4 machines. One of the offices is in another building around ...
- 1
0
votes
0
answers
11
views
Are switch MAC address tables only filled when the end devices sends the frame rather than receiving? [duplicate]
So I am going through the Cisco Network Academy courses and recently watched their video about how an ethernet switch's MAC address table is populated. If there are 3 hosts connected to the switch, ...
1
vote
2
answers
51
views
Alternative Solution to Avoid Loop aside STP
SITUATION: I have two switches SW1 and SW2. These two switches are connected with two trunk ports. While SW1 is connected to PC1, SW2 is connected to PC2.
If PC1 sends a broadcast frame to PC2 via ...
- 19
0
votes
1
answer
35
views
SFP28 port and SFP module (not SFP+)
I'm about to buy a device that has some SFP28 ports. I know that SFP28 is backward compatible with SFP+. But I want to know its backward compatibility with the SFP module.
Can I use an SFP module (...
- 551
0
votes
1
answer
286
views
How to connect GNS3 to loopback adapter on Windows 10
I'm trying to have a simple topology by connecting a router (c7200) and the local machine which is windows 10. For this I use GNS3 GUI (not the VM application). I have to do that, due to the limit of ...
- 1
3
votes
3
answers
79
views
Could Ethernet collisions be avoided using multiplexing?
I know that multiplexing can be used to combine multiple analog or digital signals over a shared medium. Thinking about it I was wondering why we can't use this technique to avoid collisions in ...
- 131
0
votes
1
answer
62
views
Will the UDP packets reach its destination?
I am trying to send UDP Packets using Linux Socket.
Working inside a Linux VM.
Server IP = 172.16.x.x
Client IP = 172.21.x.x
Both are connected via a Ethernet switch.
Doing a broadcast on company's ...
- 1
1
vote
1
answer
90
views
MAC OUI in Bits 3 to 24
One networks basics course the statement was made by lecturer for OUI (Organizational Unique Identifier) to be carried in MAC-address Bits 3 to 24. I wonder where the start bit number 3 from? It is ...
- 23
2
votes
1
answer
86
views
What is Ethernet MDI in the case of SFP interfaces
I am reading on Ethernet and I understand that for copper ports, the MDI is the physical connections from the PHY to the medium's connector, including the physical port itself, where the cable is ...
- 139
5
votes
2
answers
621
views
Can a jumbogram (giant data packet) be used at a large scale (in WAN for example)?
There are many scientific paper for Jumbo frame, even more, some real implementations and deployments. But it is not the case for Jumbogram !!
Jumbo frame (geant frame) for Layer 2; Jumbogram (geant ...
- 63
0
votes
2
answers
102
views
can we use RJ45 with cat7 sftp?
I am currently working on connecting ip cameras together .
I am using cat7 sftp cable .
according to the bellow article :
http://www.differencebetween.net/technology/difference-between-rj45-and-rj48/
...
1
vote
1
answer
282
views
Does Ethernet have a header and a trailer?
I have read that Ethernet have a header and a trailer, but in Wireshark I can only see an Ethernet header and no Ethernet trailer.
- 13
3
votes
1
answer
219
views
Length of Ethernet Preamble on 10Gb network
I know (see https://en.wikipedia.org/wiki/Ethernet_frame) that an Ethernet frame includes a 7 byte preamble of 0x55s and a one byte start frame delimiter (SFD) 0xD5, for a total of 8 bytes before the ...
- 133
2
votes
3
answers
108
views
Is it called the "MAC" protocol or the "Ethernet" protocol?
I know that there are protocols called the TCP protocol and the UDP protocol and the IP protocol, but what is the protocol at the data link layer in Ethernet called? is it called the "MAC" ...
- 21
0
votes
0
answers
20
views
OTN frames: How is partial filling and failed decoding dealt with?
I'm trying to understand some OTN concepts that are not immediately obvious from the G.709 standard documents.
I'm curious about the case of Ethernet frames packaged into ODU frames.
in case the ...
0
votes
0
answers
20
views
PTP nanoseconds synchronisation between slaves
Given the following IEEE 1588 PTP topology:
All slaves are identical embedded devices (hardware and software)
All slaves and the switch has PTP hardware support.
The GrandMaster does not have any PTP ...
0
votes
0
answers
41
views
How to enable ip address for all ports in the Cisco IOS Web Browser
Good afternoon, how do i enable the ip address in webui for the cisco switch you can see the picture below ipv4 is unassigned, everything looks good with me.
- 41
1
vote
2
answers
486
views
How can I connect 1000BASE-SX (multi-mode fiber) to 100BASE-TX/10BASE-T (copper)?
How can I connect an optical 1000BASE-SX SFP optical transceiver to a microcontroller (MCU) with 100/10BASE-T? When using a media converter like DP83869 both sides of the link must be configured to ...
- 19
0
votes
1
answer
43
views
What is an Ethernet Network Switch Port
I am trying to understand what an Ethernet Switch internally considers a single port.
My current understanding is that when a seller advertises an Ethernet Network Switch, like the one below, has five ...
- 103
1
vote
3
answers
357
views
How do we discover hosts on another subnet without knowing their IP or MAC address
If I have a client who wishes to send a UDP packet to another client, how would I scan for his IP address if Client 2 is located in another subnet?
If I'm trying to discover clients on my own subnet I ...
- 11
2
votes
2
answers
67
views
Why is a PoE circuit limited to 328 feet?
I'm trying to learn about PoE and a friend told me the 100 meter limitation on a PoE circuit is because of the DC voltage drop on the power channel, not the data. I had understood the opposite, that ...
- 131
0
votes
1
answer
31
views
Ethernet Basics - Switch Fabric, Managed Ethernet Switch & Virtual PHY terminology
I'm a new member to this community.
I've just started to learn and practice on working with LAN Ethernet PHYs, Switches and other ICs related to Ethernet.
However, I've a few questions where I couldn'...
- 105
0
votes
1
answer
48
views
What is this coupler for?
Someone asked me if they could split an Ethernet connection with this device. Obviously, it won't work. As far as I know, since Ethernet 10/100 uses dedicated transmit/receive pairs, it shouldn't work ...
- 101
2
votes
1
answer
271
views
Ethernet: How does receiver know end of frame? [duplicate]
I need to implement an 'ethernet-wannabe protocol' with a sender and a receiver.(only layers 1,2).
Assuming a sender\receiver model for an Ethernet frame with varying payload length.
As for the sender-...
- 145
0
votes
2
answers
63
views
Which access methods and topologies are used for 10/40/100 Giga Ethernet?
So I'm learning about different Ethernet types and it's stated that the Standard Ethernet operates at Bus/Star and uses CSMA/CD as an access method. The same is stated for Fast Ethernet and Giga ...
0
votes
1
answer
83
views
Switch with 100Mbit and 1Gbit ports - using its full capacity
There are switches with mixed-speed ports, usually 24x100Mbit + 2xGbit, looking something like this: .
How are these different-speed switches internally connected? The point is, can you use multiple ...
- 3
1
vote
1
answer
547
views
MAC address table and frame forwarding on Layer 2 switches - question about when two computers are connected via hub to same switch port
My apologies if this is not the right forum to ask this, but I am a newbie when it comes to networking. I am currently going through the CISCO Networking Essentials course, and one of the Activities ...
- 125
0
votes
3
answers
290
views
What is the difference between PTP 1588 and 802.1 AS?
What are the use cases where one is preferred over other ?
0
votes
0
answers
45
views
Can I use ethernet for point to point communication utilizing broadcast?
Hypothetically if I wanted to make a custom point to point protocol that uses Ethernet, can I use Ethernet in such a way where the two devices communicate with each other by broadcasting their ...
- 101
1
vote
1
answer
230
views
How does a computer determine that an Ethernet frame contains an IP packet? [duplicate]
So far as I can tell, there is no "Next Protocol" ID at the Ethernet / data link layer.
Nor do IP packets seem to contain any magic numbers for identification purposes.
Does the OS bind each ...
- 113
3
votes
1
answer
110
views
Why would a 285ft Ethernet single segment work at 100Mbit, but not at 1000Mbit
I am trying to install a 1000Mbit segment that is about 285ft long. It works perfectly fine at 100Mbits, but it won't do 1000Mbit. The testing devices (2 computers, 1 switch) have 1000Mbit ports. All ...
- 31
1
vote
1
answer
176
views
Router could get packet of size more than 1500 bytes?
Suppose transport layer get the segment 4000 bytes from application layer at sender site. But we know maximum MTU in layer2(Ethernet) is 1500 bytes.
My question is so fragmentation is happening at ...
- 356
3
votes
1
answer
252
views
Is there an equivalent of the Cisco/ Cisco esque command "ip helper-address a.b.c.d" on Mellanox switches?
Apologies for my newbie question. I have recently had a Mellanox switch added to the mix. I was using an "IP helper-address" to forward DHCP requests in different VLANs to my DHCP server(s) ...
- 33
0
votes
1
answer
235
views
EtherType multiplexing used by LLC layer
What's the type of multiplexing used by Ethernet (LLC layer)?
It says in Wikipedia "The LLC sublayer provides multiplexing mechanisms that make it possible for several network protocols (e.g. IP, ...
- 7
0
votes
2
answers
77
views
Ethernet compatibility
I am improving my knowledge about the Ethernet protocol. During my study, I noticed that they are multiple versions of the protocol. Example: 2.5GBASE-T and 5GBASE-T and 100BASE-TX.
I wonder depending ...
- 7