Questions tagged [vlan]
For questions about Virtual LANs (VLANs) which are used to divide what otherwise would be a single OSI layer-2 broadcast domain into multiple, logical OSI layer-2 broadcast domains.
1,223
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Connecting layer 3 switches together without trunking
I currently have 2x Juniper EX4200 and I'm looking into changing it into Ubiquiti EdgeSwitchs.
The diagram:
SW01 and SW02 are connected to each other using OSPF P2P. Both of the switches have their ...
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5
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WHY and HOW do routers and vlans break broadcast domains?
Everybody says routers (and vlans) break broadcast domains, but nobody goes into WHY that is, it seems.
What's the router logic?
Say I have three routers on my lan, with one main router and the ...
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7
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IP Helper in Multiple Access Switches
Just a dumb question..
I have 1 core switch and 5 access switches.
Just wondering if it would be best to setup the IP helper on all access switches rather than just on the core switch?
Does this ...
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2
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590
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VLANS - Layer 2 vs Layer 3 Juniper & Netgate/PfSense
I am working on setting up VLANS on a basically default switch configuration for my SMB network. They have 5 juniper ex2200 switches that are all on the same subnet and have only a default vlan. I ...
3
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1
answer
314
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cisco switchport trunk native vlan
we have switch catalyst 3850 and we need to enable the PXE boot on a port configured in trunk with configured three VLAN (4040, 4050 and 4060). To permit the PXE boot and deploy to work we set on the ...
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2
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453
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Cisco router on a stick with public ip wan (ISP)gateway
I am trying to create a router on a stick with an outside facing sub-interface with a public IP from an ISP. I have tried to configure NAT and routing but I just cant get to ping the internet. I'm ...
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1
answer
261
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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 ...
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1
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206
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Connect VLANs switch SF300 in the same switch
I have 5 VLANs in a switch SF300 configured in Layer3. I Set the switch to general mode so I could connect all the vlans. After 2 weeks that connection has been lost. Now you can only communicate with ...
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4
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418
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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 ...
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0
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2
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230
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Correctly Setting up DHCP for Intervlan Routing
I am currently building a network and would like my two switches connected to my router to automatically assign ip addresses through DHCP pools to my PC's and devices. I have 4 separate VLans being ...
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1
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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?
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1
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Managing a Juniper EX4300 In Band
Currently, our ex4300 are managed in band using irb.20.
show configuration interfaces irb
unit 20 {
family inet6 {
address 2001:db8:1::252/64;
show configuration routing-options
rib inet6.0 {...
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2
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55
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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?
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1
answer
987
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How to combine multiple ADSL lines?
Before beginning, I'm totally new to advanced network topics and not working as a professional network engineer or so. Just trying to learn some stuff.
My problem is, I have 3 different ADSL (or VDSL)...
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2
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Losing connectivity after creating a VLAN other than the default VLAN
I have a 192.168.0.0/24 network that serves three computers. There are no issues with this part of the existing network.
I have purchased a new Cisco SG350-28P 28-Port Gigabit PoE Managed Switch.
I ...
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0
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1
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What is the difference in packet structure for tag VLAN and port VLAN
I am new to networking. I just want to know the difference in ethrenet packet structure for tag based VLAN and port based VLAN. For tag VLAN, a VLAN tag is added to the ethernet packet frame so that ...
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1
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How to define trunk port between vmware esxi host 6.5 and switch? [closed]
I create some virtual machine in different vlan but i can not set trunk port from vmware to transfer vlan information.
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How to allow traffic through vlan
I have router connected directly to Antenna from G0/4 and when connected PC to G0/1 the internet working normally as Fig. 1 in below Photo.
I need to change the router place so i create vlan 500 in ...
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2
answers
189
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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 ...
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2
answers
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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-...
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4
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0
answers
64
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Arp Protect in dynamic VLAN environment
I am using 802.1x authentication with dynamic Vlan assignment(CPPM). As you may know, when a user logges in to their computer, SW attaches the user port to related Vlan. Thinking the scenario in which ...
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170
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Cannot create connection between two routers in same VLAN via switch
I currently have a Cisco 2960-24TT switch (switch1) and a Cisco 1841 router (router1) that form part of my core network connecting other VLANs and devices. The two ports on router1 have been ...
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LAG and VLAN Problems
I have an extended star network between two buildings. In each building I have a "Main" switch. The two Dell N1524 switches are connected via 4 fibre optic links over SFP+.
Now the 4 links are ...
0
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1
answer
417
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Why is this subnet config required by my vlan "snake topology"?
I must validate the bandwidth on all 8 ports of a switch. We intend to do this with a "snake" topology as described in this article: http://thenetworksherpa.com/test-throughput-alchemy-using-a-snake-...
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3
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310
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Configuring a network for 100% isolation (for security)
I'm configuring a LAN for an office. It's a new setup, and therefore there are desktops but no servers and no PC-to-PC communications - everything is on the cloud. The exception to this are several ...
- 197
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2
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288
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Using a VLAN to Completely Isolate Devices from the Internet & Other VLANs
I have a Cisco SG350-10P Managed Switch, and currently have two VLANS on it, the default VLAN 1 and VLAN 10. I want devices connected to VLAN 10 to have no ability to communicate with the internet or ...
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2
votes
1
answer
363
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Correct vlan/interface config for connection to upstream provider network
We have recently switched from HP Procurve series to HP Comware based switches. A configuration which has been working on Procurve doesn't seem to work on Comware. Here are the details:
The provider ...
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1
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116
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Is performance worse routing between two vlans on one interface than routing between two NICs with no vlans?
I have a Linux router with one interface that is connected to a switch in port 2.
Port 2 on the switch is a member of vlan2(ISP) and vlan3 (office devices).
My router is currently routing between ...
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4
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0
answers
177
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PVLANs/Port isolation in IPv6 networks
We're currently using port isolation to prevent communication between computers on the same vlan and use client isolation on our guest wifi. The reason for having this enabled is to prevent unwanted ...
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3
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Typical LANs with VLANs
When using switches which support VLANs with switches which doesn't support VLANs, can they be mixed with each other in the same network?
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3
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770
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VLANs vs subnets pros and cons
What are the pros and cons of designing an entire network using VLANs rather than design the network only using subnets?
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CSMA/CD in VLANs query
Ethernet is based on CSMA/CD. When using VLANs, the number of stations can become very high, making CSMA/CD inefficient. Are there any mechanisms that VLANs use to overcome this?
11
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5
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VLANs over internet
How does VLANs work over the internet and span across multiple geographical locations?
VLAN headers are removed when frames move to another switch or a router?
How does it happen?
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3
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336
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Cisco Switch without VLAN support?
I've been reading about VLAN and wondering is there any Cisco Switches that do not support VLAN?
So far, all switches that I found do support VLAN. This is one of the example in my lab.
Cisco-Switch-...
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1
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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 ...
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2
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4
answers
2k
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Are VLANs the same on different brands of devices?
I have 3 switches from different brand and I want to configure VLAN on them
Do these switches have to be from the same brand (Cisco or others)to be able to configure VLANs?
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1
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How can I get OSPF to see the VLANS that are trunked through the gigabit port
I am relatively new to this and I have been trying various configs but nothing is catching.
I have three routers, with various vlans.
The vlans are working.
The routers are seeing each other using ...
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3
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1
answer
268
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Router can ping and resolve hostnames, but VLANs and switch cannot
I recently installed an Adtran Netvanta 4430 to perform some basic VLANs on a network with a little bit of inter-VLAN routing, and I'm having a few odd issues, probably attributed to my inexperience ...
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1
answer
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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 ...
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2
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75
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Is there a way to manage IP space with only a switch?
Is this scheme possible?
External provider = External provider of the internet
Generally speaking, is there a way to assign a public IP address individually for each server to be used when SFP+ port ...
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0
votes
1
answer
85
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Access a device connected in another switch
I have theses two switches, 3Com 4500 and 3Com 2928.
3Com 4500 - IP: 20.20.X.X ; Mask: 255.255.240.0
3Com 2928 - IP: 192.168.1.X; Mask: 255.255.255.0
There is a printer(20.20.2.1) connected in the ...
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6
answers
5k
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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 ...
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3
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702
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Ip phone problem cannot get an ip address from dhcp using other vlans except from vlan 1
i am trying to understand native vlans. when i use vlan 1 it worked and it provides an ip address to my ip phone. When using vlan 100 it does not work even i tried using native trunking on it. please ...
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1
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76
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Device on VLAN is accessible from VPN but not from LAN
I have a Meraki MX84 with two VLANs, 192.168.213.0/24 (main subnet), and 10.4.213.0/24. I have an EdgeRouter 12P connected to the MX with static WAN IP 10.4.213.2. The issue is: when I VPN into the MX ...
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How to check vlan interface traffic on Cisco nexus 9k
I have Cisco N9K-C9396PX L3 switch which has VLAN interface configured for my LAN gateway and i want to monitor how much traffic vlanXXX handling, I have configured SNMP monitoring to pull interface ...
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1
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juniper vlan-ccc vs ethernet-ccc for eompls
In juniper ethernet-ccc transports customer's vlan end to end. Does vlan-ccc also transport customer's vlan across as well?
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2
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Does Network segmentation work using different switches connecting to router?
I just learnt basic networking. If I have 2 departments which I do not want them to access each other's networks, does using two layer 2 switches connecting to the router does the job or do I need a ...
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3
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925
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Cisco ASA 5512X does not allow connections across VLANs to internet
First time doing a network, I'm a software guy normally.
I am setting up a network to share and internet connections to multiple properties.
The goal is to segment each property onto its own VLAN.
I ...
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1
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EIGRP Holding Time Expire on VLAN Interfaces
I configure 2 Layer 3 Switches with VLANs and EIGRP route.
But it always return a message like this :
%DUAL-5-NBRCHANGE: IP-EIGRP 2019: Neighbor 192.168.20.253 (Vlan20) is down: holding time expired
...
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2
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122
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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 ...
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