All Questions
155
questions
1
vote
2
answers
79
views
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 ...
- 13
0
votes
2
answers
58
views
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 ...
- 101
0
votes
1
answer
66
views
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 ...
- 103
1
vote
1
answer
139
views
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 ...
- 113
0
votes
0
answers
97
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
564
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 ...
- 323
0
votes
1
answer
65
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
0
votes
1
answer
66
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
179
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
882
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
3
votes
2
answers
455
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
0
answers
29
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
2
votes
1
answer
140
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
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 ...
- 107
0
votes
3
answers
593
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 ...
2
votes
2
answers
663
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 ...
- 27
0
votes
0
answers
402
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 ...
0
votes
1
answer
65
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 ...
- 3
1
vote
2
answers
570
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-...
- 155
2
votes
3
answers
2k
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-...
- 21
1
vote
4
answers
648
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 ...
- 11
3
votes
2
answers
932
views
Why the network switch drop the frame acording to ethertype/length?
I have a network switch IC , and I am using to the send BPDU packet. I can send packet with 2 byte ethertype/length field like this : 81 00, 80 00, 91 00 and some special hex number. But if I try to ...
- 133
0
votes
1
answer
425
views
Do Cisco SG300 switches perform CRC error correction?
Cisco SG300 series switches are capable of detecting CRC errors as can be seen in the interface counters.
But can they correct CRC errors and pass the frame along to the destination or the only way ...
- 113
1
vote
1
answer
212
views
Why is XGMII little endian while the network is in big endian?
Why is XGMII little endian while the network byte order is big endian (RFC1700)?
- 396
3
votes
2
answers
162
views
Industrial Ethernet network design
looking for some advice on network architecture for an industrial switchroom with several constraints.
Modbus TCP devices are located in motor control centre cells, these need to connect to the ...
- 31
0
votes
2
answers
1k
views
How is Ethernet a packet-switched network?
Let's say for example there is an Ethernet switch, and there are four PCs connected to this switch. PC1 and PC2 are communicating with each other, and at the same time PC3 and PC4 are also ...
- 491
1
vote
2
answers
474
views
Can you stack Cisco 350 28P PoE switches with CAT5E or CAT6 ethernet cables?
I have four new Cisco SG 350 28P PoE switches, but no stacking cables. Can I use CAT5E or CAT6 ethernet cables to accomplish stacking them?
- 11
0
votes
2
answers
372
views
Is Spanning Tree Protocol Needed?
If there are two switches connected directly together with two links is spanning tree protocol needed? please see below snippet
2
votes
1
answer
1k
views
Cisco nexus 9396PX TX output discard on 40G interface without link congestion
We have cisco nexus 9396PX with N9K-M12PQ module (12x40G Interface), We have 8x10G L3 LACP bonded connectivity with our ISP and so far so good no issue at all. but recently we migrated that LACP LAg ...
- 4,379
1
vote
1
answer
2k
views
How does Kismet find WIRED devices when scanning Wi-Fi? [closed]
In an effort to better secure my Wi-Fi network by finding its weaknesses and mitigating them, I have employed the use of Kismet, a well known Wi-Fi security scanning tool. When I use Kismet to scan ...
0
votes
1
answer
112
views
Is there a MTBF related to port linking?
During a firmware upgrade, I've noticed one problem: An equipment keeps linking/unlinking on a specific port of a PowerConnect 3548(stp portfast, switchport access mode). I've contacted the local ...
user52167
1
vote
0
answers
387
views
How Cisco Line Protocol works
How do Cisco Line Protocol works ?
I could read this: https://www.cisco.com/c/en/us/support/docs/content-networking/keepalives/118390-technote-keepalive-00.html, about Ethernet Interfaces keepalive ...
- 1,085
0
votes
1
answer
645
views
If physical switches are necessary in a SDN
Exploring how to implement a Software Defined Network and here it explains that an SDN switch is only dealing with the data layer. But then:
Do We Need Special SDN Switches for SDN Networking?
...
- 107
0
votes
1
answer
159
views
Why doesn't Ethernet protocol support switch fabric topology?
While learning about Fibre Channel and SAN, I found the following information on IBM Knowledge Center:
A switched fabric is a fibre channel topology in which individual node
ports are ...
- 103
6
votes
2
answers
495
views
How to connect a special device in a network
I have a question which is puzzling me.
I have a couple of custom electronic devices (are identical, one is a master and the other is a slave) which implement only up to level 2 of the ISO/OSI layer, ...
- 61
1
vote
1
answer
55
views
Half duplex setting switch forwarding frame collides with host forwarding frame
So my question is regarding half duplex switches connected to hosts. Consider a case where a switch is connected to a host by a single link. In an event where a switch decides to forward a frame to ...
- 113
7
votes
3
answers
10k
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 ...
- 71
1
vote
1
answer
466
views
How to avoid microbursts causing drops?
I have a network issue that has to do with microbursts. I will first tell a bit about the network:
There are 4 Aruba/HP ProCurve switches. 1 Core switch and 3 downstream switches. All connections in ...
- 11
5
votes
3
answers
6k
views
How to debug L1 Auto negotiation issues?
One of our Linux hosts has started switching its gears recently. While checking the interface speed, I could see that the interface has switched down to 10Mbps. The NIC and Switch are capable of 1G ...
- 1,412
0
votes
1
answer
124
views
Unconnected cable in a switch
A cable plugged into a switch but unconnected on the other end, might lead to any problem in a "noisy" environment (industrial)?
It's short, 50 cm, but there are motors, inverters, power supplies ...
- 103
2
votes
1
answer
15k
views
Packet vs Circuit switching
I have a 1Mb/s link each user uses 100Kb/s when active.
With 10 user active 10% of the time, I can have 10 users in a circuit switched environment. Packet switching with 35 users, probability > 10 ...
- 499
6
votes
2
answers
31k
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, ...
- 499
6
votes
5
answers
2k
views
Does a Layer 3 switch become a Layer 4 device when telnetting?
In order to Telnet to a switch (Layer 2) we create an SVI, thus a layer 3 point of contact is made. The switch inspects each packet sent from the remote client and responds to it so that it gets ...
- 61
1
vote
1
answer
58
views
IP/Device Question
I am very new to this field and I want to ask a quick question about IP/Device HTTPS.
When we type in the IP address of the device (cisco switch, router, firewall, etc), we can access to the web ...
- 13
5
votes
2
answers
687
views
What is the springing mechanism for on the top of this transceiver module?
Some Ethernet SFP modules have them, some do not. What is the yellow springing mechanism and the attached metal wire meant for?
- 153
0
votes
2
answers
359
views
Can a switch segregate traffic that is before the switch from after the switch?
Per the question, Lets try to clarify a bit. Can a switch that has a router connected to it, segregate traffic (using a VLAN) from traffic that is part of the modem/router the switch is connected to?
...
- 11
4
votes
1
answer
619
views
How do data packets travel without merging?
I have been very interested in networking for quite a while, and I have been wondering this question. I've been thinking about this in complete binary, meaning how does a 0 of a data packet not get ...
- 43
2
votes
1
answer
4k
views
What is the EtherType of a BPDU frame sent by a switch which runs Spanning Tree Protocol
I want to know what is the EtherType field of a BPDU frame in various versions and variants of the Spanning Tree Protocol.
- 1,541
7
votes
3
answers
6k
views
Is there any reason to use a hub over a switch?
Given that hubs are essentially the same as switches, as far as I know, except they share bandwidth between all connected devices, while switches do not, resulting in faster connections. I am simply ...
4
votes
1
answer
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 ...
- 143