Questions tagged [switching]
For questions related to traffic switching and troubleshooting the traffic switching process.
393
questions
0
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1answer
49 views
Why does the Layer 3 switch drop the ping packet?
I am trying to ping from PC2 (not PC1, there's typo in the picture) to the router's int g0/0, but the packet is dropped at the L3 switch which is along the path. I have tried setting a default static ...
0
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0answers
21 views
Tracing a host in a network [duplicate]
If I have a host connected to a say patch panel port number 39 which is connected to the switch. There's a cable manager in-between and there's no easy way to find out which switch port the cable is ...
1
vote
1answer
32 views
Can use virtual port as the port mirroring's destination port?
Port mirroring can mirror several source port to a destination port(mirroring port).
I have several questions about port mirroring.
in the dest port, how to differentiate the different source port? ...
0
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0answers
11 views
Why would OpenFlow require N^2 entries for MAC address learning in single table?
I'm reading this whitepaper and trying to wrap my head around why it would require O(N^2) entries for MAC address learning in OpenFlow with single table. See paragraph 2.2.1. In my naive mind, I think ...
1
vote
2answers
64 views
Vlan vs. Subnet Broadcast Domain
It is my understanding that Vlans separate broadcast domains, but I often see people say, "subnets define a broadcast domain" as well.
Is it correct to say, "Vlans define a L2 broadcast domain, and ...
1
vote
2answers
64 views
ping in the same VLAN with multiple switches in between
Refreshing VLAN knowledge with PT7.3, I came across some unexpected behavior.
Why does a chain of switches having proper trunk configuration between them DROP packets? Trying to ping hosts from the ...
0
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0answers
8 views
Dynamic Link Aggregation Speeds [duplicate]
This might be a stupid and easy to answer question, but I can't seem to get a straight answer from anywhere.
I have the following setup.
Modem --> Router --> 8 port switch --> server
I have ...
2
votes
1answer
176 views
What is the effect of having too many bridges / routers between 2 devices?
I am building a network, with each node connected to each other using fiber media converters. They are actually a bridge with 2 ports: one Ethernet and one optical (or one single-mode and one multi-...
1
vote
2answers
41 views
How would a bridge loop occur?
As I understand it, STP is used to prevent bridge (/switch) loops, which will typically occur in the case of redundant links on a switch.
But how can a loop occur and cause a broadcast storm?
If a ...
0
votes
1answer
32 views
Unknown device mac address listed in switch table on start out
After playing a little bit with a topology randomly created in packet tracer, I figured out that the switch (Switch0) stores a unknown device mac address on start out, wich I think that it belongs to ...
0
votes
1answer
33 views
Fastest way to switch between redundant wireless links
I have a system using 2 redundant point-to-point wireless links to access the internet, and I'm trying to find the fastest way to switch between them if one goes down.
We need to switch within 1 ...
1
vote
1answer
29 views
How do (LANCOM) Tag-Based vlan groups work and on which vlan does the device respond?
I just started a new job and part of it is to manage and maintain the ICT. As the previous network/system engineer left the company i'm on my own to figure out how everything works.
I have ...
1
vote
1answer
70 views
How do computers send switches packets, if switches don't have IP or MAC addresses?
I am new to networking, so please excuse me if I am saying stupid stuff.
From my understanding, PCs are sending packets to switches, which then decide which physical port to forward that packet to. ...
1
vote
1answer
32 views
I Cannot Ping Switch to Device, but can ping Device to Device
I'm currently troubleshooting a network i built and I'm having an issue with ping connectivity, i have set up DHCP and DNS and my end devices can get IP's from DHCP as well as i have intervlan ...
1
vote
1answer
73 views
Switch doesn't learn MAC of a connected device
I am new to networks. What does it mean when a switch doesn't learn the MAC address of the connected device? And how can VLANs can impact that?
0
votes
2answers
23 views
How could the line rate of T1 be 1.544 Mbps?
T1 signal is the output of a 24-to-1 digital multiplexer whose inputs are 64 kbps each (plus one framing bit).
But a multiplexer is simply an electronic device that selects between several inputs and ...
-1
votes
2answers
46 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?
0
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3answers
43 views
Can a switch be used for either circuit- or packet- switching?
If my understanding is correct, circuit- or packet- switching does not happen inside the switch -- it happens on the network. It is a characteristic of a network and not of a switch. The difference on ...
0
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0answers
15 views
Since packets holds next hop MAC address, how does a switch knows to which port to send a packet to a destination? [duplicate]
Lets say a switch has 4 ports : P1, P2, P3, P4
Host A is connected to P1
Host B is connected to P4
If Host A wants to send a packet to Host B, the packet will have as destination address the MAC ...
2
votes
4answers
951 views
Will IP cameras increase the traffic in our local network?
We need to place 16 IP cameras (4MP) to monitor a warehouse, where all these cameras will be handled by a CCTV.
We have 2 options:
Connect these cameras through the same cables under the same switch ...
0
votes
1answer
37 views
Why does HPE disable STP by default? [closed]
It this certainly true that switches needs STP to avoid loops or broadcasts storms, but recently I saw the configuration of my Hewlett Packard switch and I noticed that it has STP feature disabled by ...
0
votes
2answers
66 views
VLAN based subnets, where should I untag a VLAN?
I have attempted to search this problem but I don't really know how to explain it properly (possibly a sign I've taken on more project than I can handle).
Anyway I am currently working on chopping ...
5
votes
2answers
217 views
Whats the difference between VOICE VLAN and ACCESS VLAN
Can someone please tell me the difference in Layman's termsfor these 2 configurations?
interface FastEthernet0/1
description PHONES
switchport mode access
**switchport voice vlan 51**
spanning-...
1
vote
1answer
63 views
OSPF neighbor not working
I'm currently designing a spine leaf network, 2 Spine switches and 4 leaf switches.
btw this in packet tracer.
So in order its Spine1# and Spine2#, then Leaf1#, Leaf2#, Leaf3#, Leaf4#, and addresses ...
3
votes
1answer
71 views
Why can't get host's mac address on l2 switch through snmp? But can get it on l3 router
I am trying to get computer's mac address through snmp.
I have an envirmont in GNS3:
l3 R1's image is vios-adventerprisek9-m.SPA.157-3.M3
l2 SW1's image is viosl2-adventerprisek9-m.SSA....
0
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0answers
93 views
when to disable CEF on an interface
i am currently learning about CEF and i came across the command "no ip route-cache cef", which i do understand what it does, essentially, it enables Fast-switching/process switching on an interface.
...
1
vote
1answer
37 views
How does the swtich know if a packet needs layer 2 switching or layer 3 routing?
I have a network topoloty as follows
A --------- B --------- C
/|\ /|\ /|\
/ | \ / | \ / | \
A1 A2 A3 B1 B2 B3 C1 C2 C3
A, B, C are ...
2
votes
2answers
257 views
Can a single subnet work across several switches?
New to networking and studying hard but limited access to a kit to try things at the moment...
My question is - if I had, for example, two Layer-2 switches cable connected, could I have devices on ...
2
votes
1answer
83 views
How does a switch port connect to any other port?
According to Data Communications and Networking by Behrouz Forouzan, a packet switch has four components: input ports, output ports, routing processor, and switching fabric. The basic architecture ...
3
votes
1answer
82 views
Query on PTP Transparent Clock
I had a query in PTP Transparent Clock(TC), Please consider the below picture for my question.
I will try to express my question with the help of a real world example
Say, two places Place_A <----...
2
votes
1answer
76 views
ICMP message doesn't leave NIC of PC
I got an interVLAN configuration a.k.a 'Router on a Stick'. I can ping all the workstations with each other, except PC9 (refer to image).
I did a simulation and found that the packet does not even ...
0
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0answers
10 views
Finding device using Avaya Configuration and Orchestration Manager
Is it possible to search for a specific device using either it's IP or MAC address using Avaya Configuration and Orchestration
Manager
0
votes
0answers
26 views
Cisco Virl instace issue
i'm using cisco virl on dcloud and when i try to run my topology consisting of 2 ios routers and an iosl2 router i get an error... stating that i've exceeded quotas, required 4, available 0.
Any ...
0
votes
2answers
44 views
Why doesn't kernel itself had entire L2/L3 protocol stack? [closed]
I know kernel itself handles protocols in layer 2, layer3 and layer 4 at ipv4 stack, but why can't kernel itself doesn't have protocols such as STP/RSTP/xSTP/OSPF...etc, implemented.
Why should we ...
2
votes
1answer
588 views
What is the purpose of native VLAN on a trunk link?
Most VLAN articles I've read recommend avoid using VLAN1 for ports with untagged traffic (aka access ports). I've heard enough of this nonsense. Except for the reserved values of 0x000 and 0xFFF, a ...
1
vote
1answer
49 views
IP Routing and Switching Interface Speeds
I have a question that relates to routing and switches. I am looking to set up a new Firewall that will handle the routing for the network and attached to the Firewall will be a switch. Here are the ...
5
votes
6answers
3k views
packet routing between subnets on same vlan
I am trying to understand how packets are routed within the same VLAN. I understand that typically there should be a 1:1 mapping between VLANs and Subnets. However if i deploy the following ...
1
vote
1answer
109 views
Why Do We Use STP (Spanning Tree Protocol) or RSTP (Rapid Spanning Tree Protocol) When Packets are Not Routed Optimally?
I am new to networking so this probably a naive question. I've been reading up on the spanning tree protocol and understand why it's necessary in a network (it prevents loops) and I understand that ...
0
votes
1answer
51 views
Unicast Adjacency Routes Nexus (AM) Cisco Nexus
I have an odd situation. There is static route on my Nexus 7700 that routes anything for specific subnet /24 to a F5 LTM Load Balancer, external VRRP interface 10.x.153.15.
As you can see below, ...
3
votes
3answers
579 views
LACPDU packets to pass through unmanaged switch
I have two buildings connected through the CAT6 cable and both ends have cisco-sg350 (capable of etherchannel). Due to the limitations of the cable both the switches are connected through a unmanaged ...
2
votes
2answers
260 views
Clock Synchronization in a Network
I had a query in Clock Synchronization in a LAN.. If we already have clock synchronization in a network with the help of preamble field in an Ethernet frame.
Why should we need still protocols such ...
1
vote
1answer
55 views
Port mirroring question
I've got some questions about my port mirroring configuration. I'm working with alcatel omniswitch.
After configuring port mirroring my destination port is loosing network connection and it can't ...
0
votes
2answers
246 views
How can i find which cisco switch port is connnected to specific port of Fortigate?
there is any way to find that which switch port connected to mgmt port of fortigate?
for example can i enable lldp on Cisco switch and Fortigate together?
Fortigate 1500D (version 5.6.2) and switch is ...
0
votes
1answer
75 views
STP Shut Down Port for Camera on HP Procurve
I have a VLAN dedicated for camera devices. We have learned that some camera ports keep going into the down state, and the logging indicates it is caused by STP:
sw404(config)# show logging -r 7
...
1
vote
2answers
92 views
Cisco Catalyst 9410 - Using Default Gateway versus ARPing for locally connected host
I may be missing something extremely simple here, but im at loss trying to figure out what this Nexus switch is doing.
Here is the topology:
DISCLAIMER!
I had made a mistake on the diagram by ...
1
vote
1answer
70 views
Can different VLANs have same subnet? [duplicate]
When talking about VLANs I often see examples like this:
VLAN 10 - 10.0.10.0/24
VLAN 20 - 10.0.20.0/24
Different subnets yet different VLANs. I understand this is a must if we want communication ...
0
votes
1answer
45 views
Setting all switchports as tagged for 200 x VLANs?
question:
should I expect any performance hit from enabling 210x tagged VLANs on ALL 24x ports of a switch (or alternatively setting ALL 24x ports as trunk ports)
background / equipment:
We have a ...
0
votes
2answers
45 views
Is datagram switching only possible with routers?
So datagram switching is when packets from same original message travel different paths from source to destination. This cannot happen with switches because switches would just run STP thus ...
0
votes
3answers
86 views
Bridges, hubs, switches and repeaters in subnetting
I'm learning to subnet and I'm constantly doing exercises on paper about this topic. I'm trying to breakdown a network into smaller subnets, given the number of hosts for each one. For now, I only ...
1
vote
1answer
85 views
dhcp client not receving the ip address using two switches
1) In Router 4(R4)
i have configured the 2 dhcp pool. first dhcp pool with ip address 150.10.10.0/24 and second one with 150.20.10.1/24 in subinterfaces f0/0.1 and f0/0.2 and encapsulated using (R4(...
