Questions tagged [ethernet]
For questions relating to Ethernet networking, as defined by the IEEE 802.3 standards.
899
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Tipical bandwidth required for real-time video stream [closed]
What is the optimal ethernet bandwith for streaming a real-time video versus several video characteristics (e.g. Resolution). Can you share a dimension guideline?
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1
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49
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802.3-2022 MAC frame vs Ethernet Frame
I was looking through the 802.3-2022 standard for a project and I found something that confuses me. For context, the standard defines a "MAC Frame" as "MAC frame: Consists of the ...
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1
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59
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IP MTU and Interface MTU
So im facing a problem with understanding which MTU(ip MTU or interface MTU) is the one responsible for fragmentation. I know that ip MTU is at layer3 and interface MTU is at layer 2.just an example: ...
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1
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18
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Naming difference between AltA and AltB 802.3bt pinouts
I have to test the pinouts and polarities of a PoE PSE because we are suspecting an odd behaviour. 802.3bt has a table wheren te possible and allowed pinouts are specified, but for Alternative-B, the ...
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2
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112
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10Base-T Half Duplex Segment Length 100m?
Considering 10Base-T Half Duplex...
Is the maximum segment length of 100m a timing constraint (from CSMA/CD)?
Is it derived from the slot time / minimum packet size?
Or is it an electrical performance ...
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1
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1
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76
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With respect to Juniper MXs, how does flexible vlan tagging differ from encapsulation extended vlan bridge?
Can anyone please explain the difference between flexible vlan tagging and encapsulation 'extended vlan-bridge'?
Does setting the encapsulation 'extended vlan-bridge' put all sub interfaces into ...
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2
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94
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How do switches route ethernet packets - when there are two switches in series between origin and destination?
I would like to introduce my question with the following example:
Let us say we want to sent an ethernet packet from computer A to computer B via a switch
We sent the packet with destination BBB from ...
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0
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1
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62
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replace analog phone with VoIP door box over 2-wire Ethernet?
Large office buildings and warehouses use analog phones at remote access points beyond the reach limit of 2-pair Ethernet. The newer 2-wire Ethernet has much greater reach and can provide PoE to the ...
1
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1
answer
66
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Cisco catalyst 3750 switch fault
Please I need any help or advice I can get. My switch was working fine all of a sudden the computers connected to the switch stop receiving connections. Upon checking the switch, I discovered all the ...
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1
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42
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Baffled: No continuity but excellent speed on six new Cat6 runs
For my first post on Stack Exchange I have a situation that seems to be impossible: fast internet on cables that show no continuity.
I just installed 16 Cat6 ethernet runs in an office. All of them ...
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1
answer
34
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Is there a null EtherType for packets that are only going to be handled at Layer 2?
I'm sending data into a VM via a Virtio interface, and for whatever reason I want to do Layer 2 routing with the interfaces in promiscuous mode. I know what to use as the source and destination ...
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60
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Is it possible that not adhering to a standard color coding in ethernet cables would affect performances?
I have two gigabit devices connected to a gigabit switch using cat 5e ethernet cables, but the wirings on the RJ45 connectors do not respect any of the established color standards, because they were ...
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2
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52
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Does Ethernet work at the FLIT level?
Does Ethernet work at the FLIT level? If yes, then how are the frames converted into flit and vice versa?
If not, then what's the reason?
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Gigabit Ethernet downgrading to Fast Ethernet - can it tolerate loss of any individual wire? [duplicate]
I have read that a damaged cable that used to work at 1000 Mbps can still be used at 100 Mbps. Does the specific wire inside matter? Say, wire 1 being damaged versus wire 5 or 8? Will two auto-...
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172
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Why does 1000BASE-T require a crossover function?
IEEE 802.3-2018 §40.8.2 Crossover function reads:
Although the automatic MDI/MDI-X configuration (see 40.4.4) is not required for successful operation of 1000BASE-T, a crossover function must be ...
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102
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Setting the EVPN VXLAN Interconnect ESI for Data Center Interconnect (Seamless EVPN VXLAN Stitching)
With reference to Juniper Networks , when implementing data center interconnect (DCI) using seamless EVPN VXLAN stitching , why do we have to define iESI (interconnect ESI) to stitch VXLAN VNI from ...
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169
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Are the IEEE 802.3 Clause 40 1000BASE-T MDI-X signal names wrong?
IEEE 802.3 Clause 40 specifies the 1000BASE-T MDI and MDI-X connector pin-outs as:
Below, in §40.8.2, it says
For a PHY that does not implement the crossover function, the MDI labels in the middle ...
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2
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182
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Is there any protocol between MAC layer and PHY layer?
If I read the IEEE 802.3 spec. correctly, there has no protocol between the MAC layer and PHY layer. There's only a few signals such as signaling whether PHY is ready for transmission and whether MAC ...
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0
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Fast port connection and ability to daisy chain unmanaged switches on Cisco Catalyst [duplicate]
I have a Cisco Catalyst 2960-S that I use in a home environment.
In the configuration I currently have (very basic, basically just switchport mode trunk on upstream and switchport mode access on reset ...
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1
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94
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Do unmanaged switches automatically do bonding/multi-link? [closed]
If i have 2 cheap unmanaged non-smart consumer level switches such as "Netgear GS308", do they support having 2 cables between them, and effectivly having 2gbit transfer between them? or ...
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141
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Are integrated networking devices, frequently called routers, of the switch type or of a router / NIC type?
Odom,Wendell-_CCNA_200-301_Official_Cert_Guide,_Volume_1.pdf :
many SOHO Ethernet LANs today combine the router and switch into a single device. Vendors sell consumer-grade
integrated networking ...
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1
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254
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What are different encoding schemes used in gigabit ethernet?
I was reading about digital transmission, there are many steps namely:
Analog to Digital conversion
Source coding
Channel coding
Line coding
Pulse shaping
Modulation
Multiple access techniques
...
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1
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40
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rj45 ethernet coupler
I have an outdoor rj45 ethernet coupler where 1 side of it has a flat ethernet cable plugged in. When I test the whole connection with ethernet cable tester the 2nd light is always off where the other ...
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3
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785
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Yealink & Aruba 1930 Switch Connection Issues
Good day,
I have connectivity issues on my network.
I recently installed new Aruba Instant On 1930 switches with POE and SFP+.
After the new install I started having connectivity issues to my Yealink ...
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1
answer
117
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Cannot get my servers on the same broadcast domain as backbone gateway using Aruba switches
My supervisor told me to go to the server room and connect a bunch of servers to the Department network so they are accessible from office PCs. In the server room we have 7 servers, a couple of wall ...
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1
answer
54
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Cat5 Ethernet cable between buildings passes connectivity test but switch light not lighting up and no connectivity
I have a 2 buildings about 25 metres apart and there is a cat5 ethernet cable encased in a pipe between the 2 buildings. Just suddenly the connection stopped working. If I test the cable with a ...
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0
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23
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Just testing a 2 pair twisted internet cable having 4 wires [duplicate]
I am having a problem with my 2-pair ethernet cable. I have connected the 4th, 5th, 7th, and 8th pins, but the 4th pin is not working. I have checked the RJ45 connector and the cable with a multimeter,...
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1
answer
30
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OVS pop_mpls action returning invalid ethernet frames
I am currently running into walls when trying to pop an mpls label with ovs.
I currently have two interfaces on one ovs instance connected to ports eth0 and eth1. I define a flow on eth0 to pop an ...
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1
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210
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Negotiate at 10 Gbit/s but gain lower speeds due to issues?
During the autonegotiation process, network devices communicate and determine the highest mutually supported data rate. In the case of a network adapter supporting both 10 Gigabit per second (10Gb/s) ...
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Ethernet frame's source mac-address out of a port in an ARP request forwarded to an interconnected switch towards an end host
PC1 ----- (P1) SWITCH1 (P2) ----- (P2) SWITCH2 (P1) ----- PC2
Assume two network switches SWITCH1 and SWITCH2 are interconnected to each other through their ports P2 respectively present on each ...
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2
answers
93
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How to connect HP 2930-8g to the cisco CBS350-8g switch unmanaged?
I want to Connect HP 2920-8g to CISCO CBS350-8g. I tried HP sfp ( J4859D ) in HP and CISCO working fine,
with HP and Cisco switch and cico sfp (MGBLX1) and programmed
switch(config)# allow-...
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1
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583
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Calculate Ethernet frame [duplicate]
I have a couple of confusing problems on my course, so I decided to ask here.
The question is:
What is the minimum size of Ethernet frame for a network speed of 100MBps* and maximal segment of 100 ...
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3
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181
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same rack connection: better RJ45 or SFP?
For a connection between two devices on the same rack:
Is there any notable difference or advantage between using 1Gb SFPs and using Gb Ethernet ports? (making a bonding/etherchannel).
I know for ...
0
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1
answer
443
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IP and Ethernet endianness
I'm completely new to the topic, I've read that Ethernet sends Bytes in a Big-Endian way, but that bits are sent with Little-Endian. I've also read that IPv4 uses Big_endian order. So my question is, ...
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2
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433
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Is there a way to find all MAC addresses in an Ethernet network?
How can I find all MAC addresses connected to a LAN network? Is there a way or protocol to do this?
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1
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93
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Camera instead of ethernet cables
My electricians messed up and installed some sort of camera (or very old cat3?) cables, instead of the requested ethernet cables (see picture). Now I have two of those, running for about 15 meters ...
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2
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92
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Reach IP in a different subnet
I have two Ethernet devices:
One is 10.1.1.10 with a netmask set to 255.0.0.0
The other is 10.255.253.5 with a netmask set to 255.255.255.0
Why can't I reach the second device from the first one (...
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2
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543
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Adapting 10GBaseT and NBaseT with a PoE Injector?
Suppose I have a device that supports 10/100/1000/10GBase-T ("Firewall") and another device that supports 10/100/1000/NBase-T ("Modem").
Now, I could connect these two devices ...
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1
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115
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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
...
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2
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142
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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 ...
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51
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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? ...
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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 ...
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473
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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 ...
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3
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151
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Wifi solution to connect two warehouses on to same network
I’ve just acquired a second warehouse however it’s approx 100m from my current one.
To save me the headache of having two wifi systems what’s the best solution to bring my current wifi network into my ...
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312
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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 ...
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2
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387
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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 ...
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2
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726
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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. ...
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9
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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
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0
answers
104
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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 ...
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2
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673
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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 ...
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