Questions tagged [ethernet]
For questions relating to Ethernet networking, as defined by the IEEE 802.3 standards.
871
questions
0
votes
0
answers
46
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
307
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
112
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
195
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
288
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
263
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
95
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
0
votes
0
answers
28
views
Why collision domain occurs in hubs but not switches [duplicate]
if anyone knows the actual point and in depth answer to my question please help. the links in the comments didn't helped at all
Most of the websites which i saw are just vaguely saying that collision ...
- 101
0
votes
1
answer
1k
views
Size of an ethernet frame carrying an arp request using ip (no options) & ethernet?
OKay so I found that this frame has size 72 bytes with no explanation and I can't seem to be able to figure out why .
Ethernet payload will be : ip header + arp packet
Arp packet with ip & ethrnet ...
- 103
0
votes
0
answers
10
views
ARP Header's Mac Address set to 0 when broadcasting [duplicate]
I'm learning about Ethernet frames and networks and Wireshark has been very useful.
I have a doubt regarding broadcasting and ARP request, since we don't know the Target MAC address, in the ARP's ...
- 1
0
votes
2
answers
481
views
Pins #6 and #8 of my CAT6 ethernet cable are broken. Should I replace the entire cable or is it usable?
I wired up a ~40m long CAT6 cable following T568B pinout.
According to my tester, pins #6 and #8 are not functional.
I have re-wired both ends several times to make sure it's not my poor crimping; ...
- 101
0
votes
1
answer
75
views
What are the possible bottlenecks in this design?
I am currently finding myself in a position where I need to design a local network for parallel processing of large amounts of data from multiple sources. Unfortunately I lack the experience to ...
4
votes
1
answer
575
views
Noise Immunity - 1000BASE-T vs 100BASE-TX
Comparing 1000BASE-T and 100BASE-TX, given the same cabling and distance, in an environment with substantial electronic noise, theoretically, which of the two will be more resistant to noise?
- 143
1
vote
1
answer
72
views
How can I use two WiFi routers with one cable to the ISP router?
Let me explain...
There is the fiber optic ISP router on the first floor, connected to it via LAN cable is a switch, connected to the switch via LAN cable is a WiFi router on the 7th.
I want to add ...
- 11
-1
votes
2
answers
131
views
Does MAC replace CSMA/CD in Ethernet?
We now that in old days Ethernet use CSMA/CD for collision domain. However, with the advent of Switches now MAC addresses are used to identify the source and destination machine. But still when I read ...
- 35
3
votes
1
answer
76
views
How Ethernet protocol is related to Ethernet types such 10BASE5?
I know that Ethernet is a Data Link Layer protocol which specifies how the communication takes place b/w nodes in LAN defined by standard IEEE 802.3. I came across a book in which there were different ...
- 35
0
votes
1
answer
75
views
Gateway with multiple VLAN IPs on one NIC [closed]
I would like to separate several hosts from the local network and put them behind a firewall. I would like to use VLANs to "physically" separate them instead of using just different subnets. ...
- 101
0
votes
1
answer
188
views
Creating a distributed ethernet using a single mode fiber ring
Can I create a distributed ethernet using just 1 x core of a single mode fiber ring ?
Update (Sep 2022):
The following is what we've implemented and works great. It's one of the options discussed in ...
- 103
4
votes
1
answer
522
views
Can a radio share a MAC address with the ethernet interface of an access point?
I have a situation where I have found the BSSID to have a MAC address congruent to the MAC address of the ethernet interface.
Is this possible?
Does this happen with all access points?
- 97
0
votes
2
answers
59
views
Robust Ethernet connection next to high power machines
We are creating a robot for facade treatment (cleaning, painting, drilling). I have few beginner level questions.
An industrial robot with it's controller and our computer is placed at the top of a ...
2
votes
1
answer
92
views
Carrier Ethernet - Implementation detail at the UNI needed
Metro Ethernet Forum (MEF) standard number 4 identifies two items of equipment - the UNI-C and UNI-N (UNI Client and UNI Network respectively) - on either side of the UNI. In so far as general terms ...
18
votes
3
answers
6k
views
Why does an Ethernet cable have four pairs?
I'm curious about why 10Base-T and then 100Base-T Ethernet networks used cables which had four pairs if they only needed two? Were there some cables that only had two pairs?
If we wanted to increase ...
- 183
2
votes
1
answer
109
views
If one of hub is damaged,will it cause others hub damage too?why can't i enable the rapid dual homing
There is a multi-ring topology, combined with 8 Hubs and 2 switches, i want to ask two questions
1. If H3 is damaged,but the fiber is still ok, will H2 damage too in the future? i have thinking to ...
- 91
0
votes
1
answer
298
views
Is there a network cable tester device that tests the cables with realistic frequency instead of on/off leds?
I am not looking for a specific product recommendation. I am looking for a category of cable tester devices, so I can do a targeted search.
I have an rj45 cable tester that tests the ethernet cables ...
- 103
2
votes
3
answers
113
views
Terminology: Disentangling the word 'Ethernet'
I’m trying to disentangle the common usage of the word “Ethernet”
I believe when people say 'Ethernet' they refers to 2 thing simultaneously:
a Protocol
a Transmission Line
That is when someone says:...
- 23
5
votes
4
answers
2k
views
Is there a ping equivalent on layer 2?
You can use ping to measure RTT between you and an IP host and thereby confirm connectivity. Is there an equivalent that can be used on L2/Ethernet with MAC addresses?
i.e. l2ping AA:BB:CC:DD:EE:FF
(I ...
- 153
0
votes
1
answer
427
views
According to appropriate standards, which Ethernet cable jacket colours should I use? [closed]
We have the following connections.
User desks to patch panel to non-PoE switch
CCTV to patch panel to PoE switch
WiFi access point to Patch panel to PoE switch
Floodlight to Patch panel to PoE switch
...
- 149
0
votes
1
answer
43
views
Does creating frames done by device drivers?
If I got it right, TCP and IP packets are created normally by software running in the
kernel. So when I as a user open up a socket of type TCP/IP and send a message, the kernel takes care of all those ...
- 137
0
votes
0
answers
22
views
What is preamble in ethernet frame and why is it used? [duplicate]
I've searched all over the internet and every say that it synchronize the receiver clocks. What does that mean?
Also I've seen another definition that preamble gives NIC time to realize a frame is ...
- 97
0
votes
2
answers
134
views
Are ethernet connections trackable? [closed]
If I plug into the wall, is it track-able which room the ethernet connection is coming from? If possible, how?
- 1
0
votes
2
answers
498
views
CSMA/CD: minimum frame size for Fast Ethernet and Gigabit Ethernet
In csma/cd the minimum frame size that should be transmitted in twice the propagation time for the standard Ethernet cable (10 base 2 or 10 base 5) . But how to maintain the same frame size for the ...
- 356
0
votes
1
answer
75
views
Problems with cat 6 cable
Our company have all the networking with cat 5 cables. My problem is: one of our employees bought a cat 6 cable but we don't have any rj 45 for this cable, we only have for the cat 5. I tried so many ...
0
votes
1
answer
92
views
Lan and baseband channel
We know the baseband line at one time send or receive data(half duplex). If more than one host send data at same time may occur collision. In bus topology see the same thing. Inspite this in home, ...
- 356
0
votes
1
answer
52
views
How do i prevent dataloss, when installing an ethernet cable fairly close to an electric cable? [duplicate]
I want to install an ethernet cable and an electric cable (230V) right next to each other (same cable tube, currently 20mm in diameter, length up to 100m (i think its under 75m but i didn't measure ...
0
votes
2
answers
118
views
What type of network cable is this and will CAT6 provide me any benefit over this?
I have a router configured as access point and connecting to the host router with four wire twisted pair cable which looks like below:
I have some doubts regarding this:
What type/sub type of this ...
- 451
0
votes
1
answer
22
views
Achieving clock synchronization via 1588V2
Is it possible to achieve frequency synchronization between 2 network points (not TOD but actual frequency) - by using 1588V2 alone ?
Or do we have to use SyncE for that ?
- 101
0
votes
1
answer
52
views
Does bipolar encoding need a clock
if it does then when will a clock be useful in decoding bipolar signals
'I was thinking' it just see if it detects a -voltage & a +voltage and do "save " the bits accordingly
0
votes
0
answers
17
views
Finding IP address [duplicate]
I have a device (logger for data acquisition), ut seems that someone has changed it's default IP address and lost it. I can't access it. Is there's a way to find it's IP?
0
votes
2
answers
2k
views
Can a bad ethernet cable cause lag spikes?
I needed to extend a 50m cable by about 1 meter. I know that the best solution would be to make a new run but it's very difficult to swap the cable so I tried to avoid it.
As RJ45 couplers would take ...
0
votes
1
answer
169
views
Exceeding SFP manufacturer maximum distance
What are the consequences of exceeding the SFP manufacturer maximum distance ?
Example from Cisco, Table 2. SFP+ port cabling specifications of https://www.cisco.com/c/en/us/products/collateral/...
- 1,085
1
vote
1
answer
358
views
Does 10BASE-T contain four wire pairs or two-wire pairs and why is it if it's four wire pairs?
As far as I know, 10BASE-T and 100BASE-T (types of UTP) use two pairs of wires, while 1000BASE-T has four pairs of wires.
But when I look up the photo of 10BASE-T on google, it indeed contains four ...
- 111
0
votes
1
answer
422
views
How is data flow in a twisted pair cable?
If i use a ethernet cable (twisted pair cable) in what form the data is flowing - digital or analog signal. And in pair 1 that is wire no 1,2 there is transmit+, transmit- respectively. how is pair 1 ...
0
votes
1
answer
162
views
Did a "network hub" actually send and receive all data to every node? [duplicate]
In the early 2000s, I went to a store and bought a Netgear "network hub" either exactly this one, or extremely close to it: https://upload.wikimedia.org/wikipedia/commons/d/d9/...
- 1
0
votes
2
answers
438
views
Can Ethernet frame be fragmented?
If there is IP fragmentation, is there also Ethernet fragmentation?
I tried to google it but there seems to be no such thing.
So what if, for example, we encapsulate Ethernet into ATM, what would the ...
- 471
1
vote
2
answers
412
views
Losing connection when connecting a server to Stratix 5400?
I have a problem that when connecting a server to Stratix 5400 the Stratix loses connection for some seconds which causes a Safety Fault for the line because we have Safety PLC’s any help.
,Software ...
- 11
0
votes
3
answers
312
views
Does duplex depend on the cable or the interface?
I wanted to know what made a Duplex system work? I always thought it was the Switch that made it work. But I just read on my Cisco course 2 things that made me question it.
It said this, and made me ...
- 3
2
votes
1
answer
176
views
If SFP supports 4.25Gbps why don't they make a SFP RJ45 2.5Gbps module?
SFP transceivers support speeds up to 4.25Gbps, but SFP RJ45 only support 100/1000Mbps
Why is there no support for 2.5Gbps RJ45? Is this a technical limitation or did no one ever decide to make SFP 2....
- 135
1
vote
1
answer
313
views
Are there any advantages of using a crossover cable to directly connect modern devices?
Modern devices no longer need a crossover cable to directly connect via an ethernet cable.
But are there any advantages of using a crossover cable anyway?
For example, does a crossover cable decrease ...
- 113
0
votes
1
answer
184
views
How is the maximum speed of an ethernet cable detected?
Let's say two hosts are connected with an Ethernet connection. There is a similar sounding question that talks about how the two LAN cards determine the link speed by sending and receiving auto-...
- 103
0
votes
1
answer
186
views
Geographic or Physical Limitations of VLANs
Is it incorrect to have a layer-2 broadcast domain cross long distances or multiple sites?
- 4,349