Questions tagged [switching]
For questions related to traffic switching and troubleshooting the traffic switching process.
480
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Why Can't Routers Between a Switch Communicate with Each Other while Routers Between Two Switches can Communicate without VLANS [closed]
I am new to networking and just learning routing and switching in layers 2 and 3. I have two different topologies that baffle me when trying to send packets. In the first topology, I have 4 routers ...
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19
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Hybrid OpenFlow Ports on Allied Telesis Switches
I have an Allied Telesis AT-IE340-20GP switch.
I want to make port (12 for example) a hybrid port.
With hybrid I mean it should be able to forward packets when communicating with a non-OpenFlow port (...
1
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1
answer
62
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Wrong subnet configuration works anyway in a shared bus, but doesn't work in switched lan. Why?
I was told that this configuration (which contains an error in DNS mask which is /23 instead of /24) works only because it's a SHARED bus. If it was a SWITCHED lan, the DNS responses from DNS to A ...
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4
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152
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Why non-blocking switch needed?
I know that a non-blocking switch is a switch that can manage the sum of the maximum theoretical speeds of all its ports.
However, as the term suggests, "theoretical" maximum speed is just a ...
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2
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84
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Understanding VLAN Tagging for Network Segmentation
I've been reading up on network segmentation and the use of VLANs to enhance security and network management. However, I'm still a bit unclear about the concept of VLAN tagging. Can someone please ...
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15
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What is the practical use of bandwidth-delay product? [duplicate]
It's given that the bandwidth-delay product defines the number of bits that can fill the link; while the sender can send (1+(2 * Propagation Time / Transmission Time)) units before getting ...
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2
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97
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Inter-VLAN using L3 switch
There are 3 VLANs 10, 20 and 30 on these switchs. Everything such as VTP, DTP are working fine. The problem is that inter-VLAN seems not to work correctly. IP routing is activated on the L3SW (even ...
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76
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Q-in-Q on QFX5120
I'm building dot1Q tunneling between 2 Cisco routers and when I used only 1 QFX switch it all works fine.
However when I try to use 2 QFX switches with basically the same configuration I cannot get ...
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1
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2
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138
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What Does Exactly Happen When A Switch Is Connected To A Portfast Port?
I am trying to get a thorough understanding of what does happen when a switch is connected to a portfast port on another switch that is part of a stable STP network in case of:
1- the port has no ...
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2
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2
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394
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Switches in chain topology for ~40 devices
I am currently looking at a network topology consisting of ~40 DUTs. In this network, there is no hierarchy (like access core and distribution), and all the switches are connected in chain topology. ...
- 121
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1
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45
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how can a STP switch time out MAC addresses from the table in Listening state?
I am looking over some materials describing STP's port states (the original version from 802.1d) and they say that a port in Listening state can not modify the MAC address table (it doesn't learn new ...
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978
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Two switches, double connection, no LACP: how does it work?
We have a network with an HP 1910-24 and a V1410-16 (unmanaged). The two are connected via two network cables, but there's no Link Aggregation configured on the 1910, and all the connections are ...
- 153
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2
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218
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ethernet switching table is empty | vQFX | EVE-NG
I'm new to Juniper switches. I configured vlan10 and assigned two ports to the relevant vlan.
root> show vlans
Routing instance VLAN name Tag Interfaces
default-switch vlan10 ...
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1
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1
answer
53
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In what situations is MPLS label erased from the top of the label stack in MPLS?
What are other processes that MPLS/IP routers can do with, or to MPLS label stack?
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21
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How is Control plain in MPLS used for creating label table, and IP routing table?
How is Control plain in MPLS used for creating and maintaining label table, and hold protocols for creating and maintaining IP routing table? Is IP routing table in MPLS located in Customer edge ...
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2
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63
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How did ATM switches that were implemented in a core of IP network improve QoS and higher data rate?
How can ATM switch improve Quality of service and data rate just by incorporating them into the core of IP network? What was used in the sore of IP networks before ATM switches and what is used today ...
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2
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95
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Is there parallelism in packet-switching?
Let's say there are two hosts h1 and h2 separated by a switch w set up in this manner
[h1]----link1----[w]----link2----[h2]
If we are to send a file divided evenly into two packets from h1to h2 using ...
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31
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RSTP topology change notifications flow - packet comms
I think I understand the proposal/agreement sequence within RSTP, but not quiet sure about the below. Let's say bottom bridge had priority 20k and was root, and it increased priority to 36k. Root must ...
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65
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How bad is doing a back-to-back connection to do VLAN mapping (vlan-stacking limitation)?
the object sounds like a newbie questions but there are good reason for it in the context of bridge-domains and vlan-stacking.
Here below a picture to give a bit of context
In short I realized that ...
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95
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Cisco 3850 not saving port config [closed]
I have a 3850 and whenever it reboots it loses its config. Power went out for a second today and it lost its port config. Weird thing is - it keeps the vlans. I have gone through this three times. I ...
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1
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565
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Not shows Mac address in the Core Switch
Hi everyone i have a question, i have a device connected to the port in the Core switch, It's for LAN connected to Secomia device and the LAN port is configured and we checked in the firewall we see ...
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1
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291
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Vlan 20 & native vlan 20
If native VLAN 20 wants to communicate with VLAN 20 through a trunk link what happens?
Will native VLAN be able to communicate with VLAN 20?
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117
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Cisco switch police bandwidth for IPv4 and IPv6 traffic
I am trying to limit the bandwidth of several VLANs on Catalyst 3750X (c3750e-universalk9-mz.152-4.E10.bin) and Nexus 3064PQ (n3000-compact.9.3.9.bin) switches without success...
It is necessary to ...
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1
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158
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Configuring shared uplink on l3 dell s4128f-on
I have a Dell switch s4128f-on which I'm using as L3 core switch. What I want to achieve is creating multiple vlans and being able to reach other networks through an uplink.
What I've done so far is:
...
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1
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1
answer
317
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how to limit or block broadcast traffic on ASR920 service instance EVC
I don't want to turn off all port,
I want to block completly broadcast traffic,
or the best to limit rate to 500 pps broadcast, all more to drop.
Is there any way to do it on Cisco ASR920?
I have ...
- 31
1
vote
0
answers
44
views
Optimal segment size for store-and-forward switching [closed]
Suppose we are transmitting a file of size X bits from A to B. They are connected to each other with a single switch using store-and-forward switching. Before transmission, A splits the file into ...
- 111
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3
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193
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Do telephone calls work at Layer2?
We know that Wi-Fi works in both layer1 and layer2 and travel through air in layer1.
My question is when we create mobile phone call during connection establishment phase sender Mac address and ...
- 378
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vote
3
answers
527
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Why switch uses Mac address during implementation of spanning tree protocol (STP)?
We know that layer2 switch doesn't use Mac address ,uses only certain port number to accept the frame.
But I have been read on book as well as internet that uses Mac address to find spanning tree for ...
- 378
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2
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669
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Switch won't forward a ping outside LAN despite having a default gateway
Maybe I'm just tired, but I can't get basic connectivity in my network. I've built this on Packet Tracer for the sake of troubleshooting and I've removed everything but the important elements. Here's ...
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100
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how cisco switch handle the incoming frame
[
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How does a host (HOST_A) on LAN1 send a packet to a a network more than 1 hop away and how does a router (ROUTERX) handle that packet?
Suppose there is a host, HOST_A, on LAN1 and is sending a packet.
The destination address of that packet is: 10.10.11.77
HOST_A will refer to it's routing table and see that that there is no entry for ...
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votes
1
answer
35
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mount a industrial network [closed]
my objective is mount a fault tolerance industrial network, in an already very populated factory.
the factory has many production lines and i want to treat them as a separate islands... so i want to ...
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0
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19
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Questions about how does the native VLAN work [duplicate]
I am studying about VLANs at the moment and I have a few questions regarding native VLANs and their purpose.
I've read that they are used to carry untagged traffic, and that the native VLAN is ...
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1
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656
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How do I check if a Cisco switch is connected to a SYSLOG server?
We use the Cisco C2960X switch.
Query 1: What does console, monitor, buffer & exception logging mean?
Query 2: Capture logging to 192.168.X.X which means if the switch sends logs to the SYSLOG ...
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1
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1
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Trunk seems to be allowing all vlans
Got a catalyst 2690 on a small office net consisiting of 2 vlans, 10 and 20, 10 for the lan and corporate wifi and 20 fot guests wifi.
All lan ports are config on access mode vlan 10
The access point ...
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1
answer
174
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QinQ tunneling more than one VLAN as a provider + is it possible to send QinQ tunneling on the same port where L2 tagged works
I have done some QinQ's tunneling in my history but always there was only one customer, so situation was clear for me how to configure it. I mean access dot1q port to the customer and the rest are ...
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1
answer
364
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Can I use a 40G transceiver in a QSFP56 NIC to connect to a 10G transceiver/switch if the NIC supports 10G speeds?
We're purchasing new servers that have Mellanox ConnectX 6 network cards in them, which accept QSFP56 transceivers. The card says it supports 10/25/40/50/100/200G. However, our switching backbone is ...
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1
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118
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Understand router Ip address and Mac address, Switch Mac address
Scenario:1
Suppose external Router R1 has interface a connected with interface b of the site Router R2. And Router R1 using IP address 80.0.0.0/8 for a. Router R2 has 4 subnets 80.0.0.0/10, 80.64.0....
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3
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720
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Switch: port and NIC relation
I wonder if a switch has one NIC per port? for example, does a switch with 24 ports has 24 NIC?
Many thanks in advance for your help.
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1
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359
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Total delay of virtual circuit switching? [closed]
We know that virtual circuit switching(VCS) has both features of circuit switching and datagram switching. It uses connection oriented path but may or may not dedicated that means resources may or may ...
- 378
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vote
2
answers
192
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Bridging two networks
Good days everyday. I am a newbie networking. I just have a question.
The diagram above simplify my network setting. They are all in same location. Is there a way to connect from 192.168.0.XXX to 192....
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votes
2
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99
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Connect 1GE SFP MM to 10GE SFP MM
I have a situation in which the ISP can only accommodate a 1GE SFP and single mode fibre, but we have bought 10GE SFP.
Is it possible to get the physical link up when connecting a 1GE SFP to a 10GE ...
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2
answers
129
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Multicast MAC using destination MACs
I am working on a routing algorithm which involves multicasts, my question is: Is there a possible way to convert a list of MAC addresses to a single multicast MAC address for configuration purposes?
...
0
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1
answer
417
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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
0
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2
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450
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Juniper EX Switch as router with transfer network for upstream network
So im new at juniper and networking. On my Juniper EX4550 switch i want to setup a transfer network to my upstream provider. So my upstream provider assigned a /30 subnet for the transfer network:
...
3
votes
1
answer
571
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IPv6 neighbour discovery blocked by MLD snooping switch
I recently noticed that my IPv6 multicast traffic was being broadcasted to all hosts connected to a switch, even those that had not subscribed to the traffic.
To fix this, I enabled MLD snooping on ...
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1
answer
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Does an unmanaged switch deal with IP addresses at all
My belief is that an unmanaged plug-and-play layer 2 network switch only deals with MAC addresses.
When computer A on a local network wants to communicate with computer B for example through the ...
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3
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1
answer
484
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HSRP on multilayer switch not working
I have this network topology in Packet Tracer, and i wanted to implement HSRP on both of the multilayer switches.
So what i made here is the switch on the left, both the laptop and the server are on ...
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3
votes
1
answer
646
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Storm control problem with Juniper switch configuration (EX2300)
I am new with Juniper and generally new with switch configuration. Probably screwed up a lot but anyways, I will share my configuration right after I say what I want. I am getting Internet on ...
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2
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60
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Is this description of data transmission over L3 switch correct?
So I'm trying to describe how data is transmitted over a layer 3 switch (within same Vlan and between Vlan) but I'm not sure if I have understood it correctly. Can anybody verify if this description ...
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