Questions tagged [ethernet]

For questions relating to Ethernet networking, as defined by the IEEE 802.3 standards.

Filter by
Sorted by
Tagged with
0
votes
1answer
32 views

Understanding L2 Switch (Network Noob)

I currently have the setup on the left and it works just fine... I use it to transfer data between laptop and embedded systems hardware device. (Data...Not internet) Question: What would the set up on ...
0
votes
2answers
12 views

Will using an ethernet switch change my computer's IP address? [closed]

I only have one ethernet port in my office and I need to connect two desktops that both need a constant connection to use remote desktop. The IP address changes when they get disconnected from the ...
2
votes
2answers
6k views

When is “grounding” a concern when running Cat6a cables?

I'm educating myself on how to terminate Cat 6a cables. I've seen some articles talk about "grounding" requirements because of the "shielding" in the cables. But is grounding a concern if I'm just ...
0
votes
0answers
20 views

ARP Table of Router [closed]

Consider these properties: MAC-Adresses start with 02-00-00-00-00. The last byte is the Interface Id, which is the number in the small box in each node. For example: Host B1 would be given 02-00-00-...
0
votes
3answers
71 views

Minimum MTU size on Ethernet and minimum Ethernet frame size

I am a bit confused about the understanding of the relationship between minimum MTU of MTU and minimum Ethernet frame size. We know that the maximum MTU of Ethernet is 1500 Bytes which makes the ...
84
votes
21answers
72k views

When to choose fiber instead of twisted pair (copper)

These days both fibre and twisted pair are supporting 1000BASE-T and 10GBASE-T, but when do you choose one over the other? The obvious one is maximum cable length, but what are other factors which ...
1
vote
1answer
22 views

Which type of ethernet cable for external runs to cameras and home office? [closed]

I'm sure this question has been asked a hundred different ways, but I've been struggling to piece the various bits of information together and finding quite a lot of misinformation about ethernet ...
0
votes
0answers
20 views

Will one ethernet cable do or should I install two or three…? [closed]

I have two cctv cameras, a tv and my desktop pc that I want to connect to the router about 20m away by ethernet. Will a single cable do with an unmanaged switch or should I install two or even more. ...
10
votes
3answers
18k views

Do Bluetooth Devices have MAC address with the same specification as the MAC addresses of the Ethernet and Wi-Fi Network cards?

I recently found out that ZigBee devices have MAC addresses. ZigBee is more related to Bluetooth from what I know rather than Ethernet or Wi-Fi. Do Bluetooth devices such as phones, headphones, ...
0
votes
0answers
9 views

Optical RX/TX only link [duplicate]

If I connect on one side only TX (RX stays empty in the optical LC Transceiver) and on the other only RX (empty TX) will the link come up ? Both sides are ports on a switch. I assume the RX side comes ...
1
vote
0answers
16 views

How strong a ground loop would necessitate the use of isolation transformer in Ethernet? [closed]

One reason against the use of shielded twisted pairs in residential environment is the possibility to create a group loop between equipments, as discussed in Shielded Twisted Pair (STP) termination ...
0
votes
0answers
7 views

ARRIS CM820S modem and WiFi [closed]

this if my first post on this stack! I've recently moved in a flat to see an Arris CM820S modem, which is working fine when i connect it directly to the PC using standard RJ45 cable, which is the only ...
2
votes
6answers
2k views

Why can't we create a hierarchy of hubs?

I was reading the Comptia Network+ All in One book and I came to know that we cannot create a hierarchy of hubs. My question is why so? Are MDIX ports simplex? Why is it not possible for the hubs to ...
-1
votes
0answers
11 views

Arduino parses UDP packets through Ethernet with gibberish in it [closed]

Arduino Yun (with built-in Ethernet) is connected to a PC (through Ethernet) which is connected (through WiFi) to my router. Is set to receive UDP packets from another PC (on the same network). That ...
6
votes
3answers
2k views

Posible to connect VLAN switch through dumb switch?

Is it possible to connect a VLAN switch into a dumb switch ? The router will know how to reach network connected by a VLAN through the dumb switch please ? No edge effect ? By example, a schema of ...
0
votes
0answers
34 views

CAT 5 cables work, but CAT 6 doesn't? [closed]

My setup is, Router - CAT 5 cable - CAT 6 rated wall socket - CAT 6 cable - CAT 6 rated wall socket - CAT 5 cable - PC This works fine but the speed is limited. When I replace the CAT 5 cables with ...
0
votes
0answers
21 views

Cant access wireless devices from a wired device [closed]

I have a ZTE F660 router provided by the ISP. My PC is connected through wire/ethernet cable to the router. Recently I was tinkering with a microcontroller known as ESP 8266 commonly used for simple ...
6
votes
4answers
14k views

The maximum length of CAT6 for intranet network?

Recently I purchased CAT6 cable with a length of 150 meter. I bought another CAT6 with a length of 148 meter. I joined both the cables using RJ45 cable coupler. I tested it using LAN TESTER, and ...
5
votes
3answers
7k 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, ...
4
votes
1answer
2k 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 ...
0
votes
1answer
43 views

What clear substance could be sprayed on RJ45 Ethernet terminals? [closed]

As installed by Verizon, the cat5e/cat6 cable does not plug directly into the Ethernet port of the unit. Instead, there are terminals for each wire pair (see photo). If one were to open the snap-close ...
0
votes
0answers
16 views

Juniper MX - ERPS over MPLS CCC or VPLS

I wonder if there is a possibility to implement an ERPS Ring over a few Juniper MX nodes that are interconnected via MPLS only? The only idea i have to configure this is using lt - interfaces with a ...
2
votes
3answers
4k views

Maximum packet size Ethernet Frame and IP packet

I am a little bit confused about one fact. According to the specification, the ethernet frame maximum size is 1518 bytes, and the IPv4 packet size Length field in an IPv4 header can be up to 65535 ...
1
vote
2answers
38 views

How do routers. switches, bridges and hubs deal with corrupted data?

By data corruption I mean frame/packet corruption, we can stick to the corruption due to a collision for simplicity. I know that switches can detect frame corruption if they are not set to cut-...
0
votes
2answers
67 views

What is an acceptable bit error ratio?

I recently got a job in IT infrastructure and terminating Cat5e is something relatively new to me. What is an acceptable bit error rate for 1 million packets? Here is a screenshot of a test I ...
2
votes
4answers
296 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 limitations in available IP addresses, we can't get an IP address from that ...
1
vote
1answer
69 views

Is there any difference between International and United States patch cable?

I'm looking to buy a Cat 8 patch cable. I found a cable that I like that meets ISO/IEC 11801 Class I and Class II but it is not compliant to TIA Cat8 (As defined in ANSI/TIA-568.2-D) which has ...
2
votes
1answer
2k 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 ...
0
votes
2answers
30 views

why ip protocol use fragment offset instead of index number?

I was wondering why the IP protocol use fragment offset to define the fragments of an IP datagram instead of using index number (first fragment with index 0, second with index 1, ...). We already know ...
1
vote
4answers
217 views

Can we use two pairs of UTP with hubs?

I understand that hub always supports for half-duplex communication. In that case we should use one out of four UTP pairs. However, I read that for 10BaseT ethernet two pairs of UTP cables are used ...
0
votes
0answers
15 views

using SNAP/ LLC on ethernet

Why is it not desirable to use Logical Link Control (LLC) and Sub-Network Access Protocol (SNAP) on Ethernet 802.3 frames while carrying IP packets when it is often used for wireless networks?
0
votes
2answers
32 views

Can computers connected within a Network via Ethernet monitor access the information uploaded/downloaded on a different computer

Suppose there are many computers connected within a Network. Let's take 2 examples. Computer A and Computer B, connected within the same network. Suppose, At the start of the day, say myself as an ...
0
votes
1answer
58 views

What is the wireless bottleneck speed in my simple network map?

My simple Network topology Im trying to figure out what the maximum speed is in mbps on the blue and red links. The exact specs of the wireless networks are these: IEEE 802.11b/g/n, 2.4GHz Dual ...
0
votes
2answers
49 views

Why do WiFi bridges replace the source MAC Address with their own?

Ive read quite a bit about the issues i currently have with my Aruba WiFi Bridge 501 and the failure of DHCP going through, and as far as i can tell the issue is that the bridge replaces the MAC of ...
1
vote
1answer
103 views

what's the difference between trailer and padding field in ethernet frame captured by wireshark?

The Ethernet minimum length should be 64 Bytes, so when the data is less than 46B, there would be some extra bytes padding to the end of data, make sure the frame size up to 64B. When I capture the ...
0
votes
0answers
14 views

Can the interface types otnOtu, otnOdu and opticalChannel have metrics such as ifInDiscards, ifOutDiscards?

In my understanding, the metrics "ifInDiscards", "ifOutDiscards", "ifOutErrors", "ifInErrors", "ifOutUcastPkts", "ifInUcastPkts".,,,etc are basically related to the interfaceType ethernetCsmacd. Can ...
1
vote
1answer
34 views

How does the Ethernet handles start of frame collision?

The Ethernet preamble, 56 bits of alternating 1 and 0 bits, allowing the receiver to synchronize its clock to the transmitter, followed by a one-octet start frame delimiter byte (10101011) and then ...
15
votes
6answers
25k views

How are IP addresses mapped to MAC addresses?

I've been reading about the differences between MAC and IP addresses, and why we need both of them. To summarize, MAC addresses are physical unchangeable unique IDs for every single device while IP ...
1
vote
1answer
38 views

Ethernet Link Status when when Autonegotitation is enabled

I'm trying to understand when a 10Base-T / 100Base-T Ethernet PHY device will signal a valid link, specifically by setting the Link Status bit in the Status register, in cases where autonegotiation is ...
0
votes
1answer
31 views

What is ethernet length/type 0x9104

While capturing packets on my Raspberry Pi via my Wireshark tap (sudo tcpdump -i eth0 -w - > tcpdump.data) between my MacBook Pro and eero base station on ethernet, not wifi, the following packet ...
4
votes
4answers
369 views

Layering unicast addressing over multicasts

My question has to do with layering of unicast over multicast and has two parts. Part 1. IP unicast over MAC multicast First part of the question is whether there is a standard that prohibits use of ...
12
votes
2answers
2k views

Why does Ethernet use EtherType field to determine what type of packet is in a frame instead of just looking at the packet header?

I'm studying for some networking concepts and have learned that a receiving host looks at an Ethernet frame's header to determine what protocol being used by the packet. It makes me wonder though, ...
0
votes
1answer
21 views

Direct connection betwen two Ethernet-to-wifi adapters [closed]

I currently have two computers connected via ethernet and a switch, using static ip-addresses. I would like to connect a third computer, this time wirelessly. And I am wondering whether the setup in ...
2
votes
3answers
508 views

If no CSMA/CD on switches what are they using

As far as I understand, CSMA/CD is an access method to place Ethernet frames on the wires in computer networks. I read everywhere that switches are not using this access method because they are full-...
0
votes
1answer
32 views

How does a 802.11 (wifi) frame identify the payload's layer 3 protocol?

My understanding is that the 802.11 frame header is an equivalent of ether header. In the ether header, there is an EtherType field that identifies the payload protocol, such as IPv4/IPv6/ARP etc. ...
0
votes
3answers
129 views

Clarification on when routers encapsulate and decapsulate packets

I'm an application developer working on getting a working knowledge of network engineering, so basically a newbie. I've been trying to figure out exactly when routers decapsulate frames into packets ...
1
vote
2answers
47 views

Are optical Gigabit SFP modules backwards compatible with 100Base-Fx?

My FTTH connection is using an old CareLink CL-MC-W2B-20-100 optical converter. It is labelled: 10/100 Base-T to 100Base-Fx bi-direction/single fiber media converter 10/100M Single mode WDM 20Km ...
0
votes
3answers
53 views

setting up a VLAN and joining 2 buildings through underground cabling

I am pretty much a newbie when it comes to networks so forgive me in advance if this question seems odd. So here's a situation I am trying to figure out. There's a company who operates in 2 adjacent ...
1
vote
0answers
22 views

Manually break ethernet frames [closed]

i have the next question: how can i manually create interference in fast ethernet cable or download the special program which will randomly corrupt ethernet frames (OS is not important)?
8
votes
2answers
34k views

What purpose is the Uplink port in layman's terms and do I need it?

I have an old Linksys switch (EZXS55W) and it has worked fine for many years now, but I tried to hook something up today to the last open port and noticed the device didn't work when I did this. When ...

1
2 3 4 5
16