Questions tagged [ethernet]

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

Filter by
Sorted by
Tagged with
10
votes
3answers
2k views

Why does PPP need an underlying protocol?

The Point-to-Point Protocol is (at least according to Wikipedia) a Datalink Layer Protocol. I know that different use cases exist for it but on examining the image below from Wikipedia one can see ...
0
votes
1answer
39 views

RJ 45 Ethernet cable for Industrial purpose [closed]

For an Industrial Solution, I have to use 8 Core cable more than 200 terminals to my device for maximum length of 4 to 8 meters. this for push button signal and switch indicators from micro control ...
0
votes
3answers
50 views

How does the network client pick a wifi signal, given two available frequencies?

This might be basic, but I don't know the answer... Given a router and a client, both having 2.4G (slower, more range) and 5.XG (faster, less range) frequency radios (and both named with the same SSID ...
0
votes
0answers
19 views

Is the exact endianness of an Ethernet Frame start with LSbit of Octet (MSByte)? [duplicate]

Following up this question: Confusions regarding byte and bit ordering of Ethernet Frame Just so I get the understanding correct, if I have a Destination address of the way we usually read MSByte/...
2
votes
2answers
146 views

Connecting two HP 2910al Switches using SFP to get 2Gb/s speed

I would like to Connect my two HP 2910al switches using SFPs to get a maximum of 2G links. is this possible, and how? I want to make both of them to use the IP address (ex 192.168.2.xxx). I have the ...
1
vote
0answers
48 views

Should snmpIfHCInUcastPkts include packets bigger than 1522 bytes? [closed]

Packets bigger than 1522 bytes (as counted by Spirent Test Center) are being forwarded (bridged) but not counted in the following hardware counters on an Open Network Linux device: ifHCInUcastPkts ...
0
votes
0answers
102 views

Using GNS3 to Sniffing Packets on Siemens RuggedCom RS900

I am using GNS3 to simulate an environment. I have 4 docker containers which all host Python programs. Three of the devices communicate with each other via the programs (Program 1, Program 2, Program ...
3
votes
1answer
396 views

Alternatives to 802.11* wireless bridge?

Every now and then the question arises for me to link two Ethernet segments over some kind of outdoor wireless connection. It is usually over comparatively short distances (at some places maybe some ...
1
vote
1answer
135 views

GNS3 can not ping from ethernet interface to serial interface

So I am doing a Lab for one of my classes involving ipv6 and routing using EIGRP. When I set-up the network and assign the router interfaces with IPV6 address I get an issue pinging the whole network. ...
1
vote
1answer
93 views

Wireless, powerline or ethernet right next to electric cable

I need a new point of access to our existing network. We have power sockets but no Ethernet cable on the spot. I see three possible solutions to achieve this: Add a new WiFi6 router and connect it to ...
0
votes
1answer
102 views

Implementation of multi-lane ethernet

In multi-lane ethernet, are the lanes synchronized? i.e., if the symbol of byte 1 of a packet is sent in lane 1, the symbol of byte 2 of a packet is sent in lane 2, then symbol of byte 1 will be ...
0
votes
1answer
25 views

Transmission delay of multi-lane vs single-lane Ethenet

Suppose there are two devices that can transmit with same throughput (e.g., 10Gb/s). Suppose that one device is connected via single-lane cable while the other with multi-lanes (e.g., 8 lanes). Will ...
0
votes
2answers
111 views

Ethernet frame encapsulation - multiple

is it possible to encapsulate two Ethernet frame packets into one ether packet? My search seems to indicate that there is not a way to do this, unless one was using something like VPN packets, be ...
2
votes
1answer
83 views

In an IGMP V2 membership report message, isn't the destination Ethernet address based on the multicast group IP address?

Specifically, I think for this message type the Ethernet destination address always starts with 01:00:5E, followed by the second byte of the IP address masked with 0x7F, followed by the third and ...
0
votes
1answer
42 views

Routers FastEthernet interface clock autonegotiation protocol

In routers, for serial interfaces, we need to manually set the clock at the DCE router so that the ends of the connection can communicate. I know that in this way we are using time-division ...
0
votes
0answers
11 views

Query regarding ethernet header [duplicate]

I have a query regarding ethernet header. Some representation of ethernet header have Type Field and some tell it as Length field. Which is the right one here ?
0
votes
1answer
118 views

Is MII PHY RX_DV required to stay HIGH for entire ethernet frame?

Regarding MII spec, I have a question about the RX_DV signal that I'm not able to find elsewhere: From the perspective of the Ethernet MAC, when sending a frame to a PHY over MII, does the RX_DV (Data ...
2
votes
2answers
551 views

Static speed and duplex/no-negotiate causing input error

I noticed gradually increasing input errors for a FastEthernet interface which is connected to an end-user Windows PC. The default setting for all interfaces is no-negotiate. The Foundry switch will ...
2
votes
2answers
76 views

What if my data contains nothing but Preambles and Start of Frame numbers?

Will that continually reset the receiving NIC or is there a sort of escape character that need to be used if my data contains nothing but alternating 1s and 0s in 7 byte blocks with start of frame ...
0
votes
1answer
74 views

Ethernet Frame visualization

One IP packet is fragmented in multiple ethernet frames at sender's side And at receiver's end, all the frames are combined to get back the IP packet So is there any way to see what payload each ...
0
votes
1answer
26 views

Can we use NLP/Autonegotiation to sync clock instead of preamble?

since both NLP/FLP and preamble are using predefined pulses, can we use autonegotiation as a way of sync clock, so we don't need preamble anymore?
0
votes
1answer
238 views

RSTP sending BPDUs out of the network switch?

I need some information about RSTP If the port state is blocking, discarding alternate . Should BPDU be sent to external ports? I cant see any BPDU in wireshark if the port states Alternate,Discarding ...
0
votes
2answers
241 views

How to detect start of FCS in an Ethernet Frame

I was reading about the Ethernet frame and its various fields, I noticed that the data (payload) field can be variable and is followed by a FCS field for detecting bit errors. If the payload is ...
0
votes
2answers
496 views

In practice, how much can the 100m ethernet limit be pushed?

I am faced with putting an outdoor WiFi access point about 800 feet from the nearest building. There is no power at the far end. This will require a weatherproof AP that accepts PoE I've looked at ...
0
votes
1answer
53 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 ...
1
vote
3answers
1k 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 ...
1
vote
1answer
41 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 ...
1
vote
0answers
27 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 ...
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 ...
0
votes
1answer
89 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 ...
1
vote
2answers
232 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
73 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 ...
0
votes
2answers
58 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
2answers
427 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 ...
0
votes
0answers
21 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
181 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 ...
1
vote
1answer
2k 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 ...
1
vote
3answers
2k 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 ...
0
votes
1answer
78 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
732 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
3k 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
38 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
1k 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
293 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. ...
1
vote
3answers
1k 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
4answers
250 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
2answers
277 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 ...
1
vote
0answers
26 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)?
1
vote
1answer
54 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 ...
-1
votes
2answers
51 views

Switch Operation Beyond VLAN Segmentation

What are the other operations performed by a switch which are outside the VLAN's boundaries. Is Logical (VLAN) Segregation is exactly same as breaking a switching network physically via a Router?

1
2
3 4 5
17