Switches / Hubs

21K

Solutions

17K

Contributors

A switch is a device that filters and forwards packets of data between LAN segments. Switches operate at the data link layer or the network layer of the Open Systems Interconnection (OSI) Reference Model and therefore support any packet protocol. LANs that use switches to join segments are called switched LANs or, in the case of Ethernet networks, switched Ethernet LANs. A hub is a connection point for devices in a network. Hubs are commonly used to connect segments of a LAN. A hub contains multiple ports; when a packet arrives at one port, it is copied to the other ports so that all segments of the LAN can see all packets.

Share tech news, updates, or what's on your mind.

Sign up to Post

I have a non PC device that came prconfigured with a default IP ( no DHCP option). The device is also POE powered with no other power options available.
in order to change the IP i have to get to the device's web management page. I have plugged the device into a port of a POE CISCO switch and then a laptop into the next port on the same switch, The Device had an IP of 192.16.0.1 and I gave the laptop 192.168.0.2. The ports themselves are on the same VLAN.

The switch shows both devices on the switch. However, from the laptop I am unable to reach the web management page of the device. Doing an Arp -a on the laptop shows an entry for 192.168.0.1. I also cannot ping the device from the laptop.

The switch has a trunk that goes to a router and the network assigned to the VLAN is different from the network that the 2 devices are on. But from what I understand. that should not matter as both devices are local to the switch. The shouldn't be a need for the switch to forward the traffic to the router. It should know that one device is on port 5 and the other port 6. Or am I wrong here?

On managed switches this was never an issue,
0
Announcing the Winners!
LVL 19
Announcing the Winners!

The results are in for the 15th Annual Expert Awards! Congratulations to the winners, and thank you to everyone who participated in the nominations. We are so grateful for the valuable contributions experts make on a daily basis. Click to read more about this year’s recipients!

I am using the Juniper migration tool but is this the best method when you are changing vendors from Cisco to Juniper as it relates to access switches. I need to be 100% accurate with the configs . Any suggestions much appreciated.
0
Gonna buy servers and network equipment for new office. How to determine\ calculate the uninterruptible power supply (UPS) requirement needed to protect servers, switches and routers?
0
Any good network devices, such as routers, switches monitor and management software/ tool recommend?
0
There's lot of switches, routers connected by fibre/utp in my company, however there's no network diagram or records about their connection information. How can l know and trace their connection status easily?
0
My private IP addressing is in the 10.10.10.x network, 255.255.255.0 subnet mask, 10.10.10.1 is the default gateway. Now on some computers, I am getting a subnet mask of 255.255.255.128. I couldn’t figure out why?
Can someone help me with this?

I actually replaced the switch, thinking that some ports on the switch were bad, but I keep getting the same issues.

Thanks!
0
I am looking for a step by step tutorial for a server with vlan
can anyone provide me a complete tutorial how to add windows  server 2016 with mikrotik switch CSS326  with vlan ?
0
Hi,

I am trying to setup Hot standby DHCP server2012 (two DHCP server with multi-scope)
192.168.0.0
192.168.1.0
192.168.2.0
I am using two servers with fail-over DHCP configuration. (Hot standby) with IP address
192.168.0.1 for server 1 and 192.168.0.2 for server 2

In the Cisco 3750 switch I created 3 vlans
Vlan 10 with an IP address 192.168.0.3
Vlan 20  with an IP address 192.168.1.1
Vlan 30  with an IP address 192.168.2.1

In the configuration I added IP helper-address command to refer DHCP servers
Under each Vlan interface I added two IP helper address

Under Vlan 10
ip helper-address 192.168.0.1
ip helper-address 192.168.0.2

And so on for Vlan 20 and Vlan 30

The computers work fine and got IP address and getaway for each Vlan. However, I tried to test the fail-over DHCP and I shut down the DHCP server with an IP address 192.168.0.1 and waited to get computer an IP from second DHCP server but it's not working. I Release and renew IP and nothing changed.

Is there any missing part of my configuration?

Thanks
0
Hi!

I've got a question on how to correctly setup some Unifi Access points that are connected to a dell 3024p switch. The access points are connected to ports 1-12 and port 22 is connected to our sonicwall router. I've got vLan1 is the main network and vLan20 is the guest wifi. I've got the network created in the unifi system and the vlan interface configured on the sonicwall also. The sonicwall also serves as the dhcp server for the guest wifi. All this was working on the unifi poe switch until it broke. We changed over to the dell poe switch now. I need a little help getting the conf dialed in. Currently I can connect to the internal wifi and get an ip address from our server and internet access. When I connect to the guest wifi I'm not able to lease an IP address, but if I put in a static IP I'm able to get to the guest portal and internet.

Any ideas?
Thanks!
0
Hello,
I would like to know what are the ways to migrate catalyst 9k switches already running in the network and needs to be migrated to Cisco SDA.

Current setup:

All the switches in the network are migrated to Cisco 9K.  Cat9500 is a collapsed core switches and few IDFs with cat 9300.

We wants to migrate these devices to SDA where we have DNAc and ISE in the HQ. All the cat 9k switches are enabled with Advantage licenses.

Can anyone please with steps to migrate to Cisco SDA.
0
Introduction to R
LVL 19
Introduction to R

R is considered the predominant language for data scientist and statisticians. Learn how to use R for your own data science projects.

Hi,

I have Nec ITX-3370-1W(BK)TEL POE phone and when I attached it to Cisco 3750 POE switch the phone not working while when I attached Nortel 1120E or 1140E they are working.

Any idea to fix the problem?

Thanks
0
Hi,

I have a HPE OfficeConnect 1950, I dont have the password and dont wont to lose the config. Can anyone please assist
0
Hi,

Our company internet provider set us up with a new modem which would deliver faster speeds and has the IBGP failover ability. In order to use the IBGP failover we would need to designate 1 (or 2?) IP's from our small block of IP's, or get rid of the current ones and use a larger block of IP's.

Does it make sense to just consolidate our current IP's instead of purchasing a larger block of IP's? We currently have 5 public (outside of the broadcast)

Is it best practice/ industry standard to purchase larger amount of public IP's?

Thank you.
0
Have two Dell powerconnect 5548's set up in a stack. Recently have been unable to login and when attempting ssh, I get the following error.
Remote side sent disconnect message - type 2 (protocol error): "Connection closed by server: Server reached maximum number of simultaneous connections

Open in new window

There seems to be a command for other dell switches to clear sessions however I am not seeing anything for the 5500x series. I set a session timeout and even rebooted the switch but I am still getting this error. All line connections show as locked in the web UI however reactivating the locked line through the GUI does not do anything. Anybody more familiar with Dell switches have an idea for how to resolve this error? I can currently manage the switch by console and web ui however it would be great to get remote ssh sessions running again.
0
I have  cisco switch, a 3850 and created a port channel for 3 ports.  Each port is a 10G port.  On the other side, I'm using a synology with 4 (1G) ports. I did a LACP on that side as well and bonded 3 of the ports.  It shows the link at 3000 Mbps.

On the cisco switch, the port channel shows a speed of a-1000

Not sure why it's only connecting at 1000, but when I did a speed ?, it only gives me the options of 10, 100,1000, auto and nonegotiate.  I tried auto and it puts it back to a-1000.  I tried nonegotiate and it didn't take that command.  So how do I get the port channel to run at 10G, so it can at least transfer at 3G?
0
Hello Folks

Just wondering what would you recommend for a wireless infrastructure. Let's suppose the physical survey is done and we're looking at 400 access points. Would experts recommend a cloud based solution like Cisco Meraki? Or should we get better performance/security from having on-site Cisco wireless access controller?

any suggestions would be highly appreciated.
0
2019-11-06_16-22-07.jpg
I am looking to replace a L3 switch in our datacenter but I currently do not have access to the current config.  As it sits right now, the L3 switch has some form of VLAN setup that I cannot see but I know is working.  Our datacenter has provided the following documentation, but where I get confused is on the setup of our ubiquiti edgeswitch with the trunking or vlan tagging of ports.

The datacenter has provided us static IP's on a /29 for the first routing network and a /28 on the second.  Apparently I need to create 2 VLANs where I can assign 5 ports on the switch to the /29 and another 16 ports to the /28 VLAN.  I am just a little unclear about how to go and do this is the edgeswitch unit.

They said that the second network needs to be routed to the first usable IP on the first routing network if that makes sense. Is anyone familiar with this setup and these particular L3 Switches to help me with the settings? Thank you!
0
Uplink/Integrate two seperate switch stacks

- We need connect a new Layer 3 switch with VLANS and Subnets into a dumb, legacy switch stack that has a flat network and no VLANS
- Dumb switch has all live devices plugged into it. L3 switch has test devices.
- We need all devices on both switch stacks to communicate with each other.


L3 SWITCH

- Switch 1 (Meraki MS350) has 2 VLANS and 2 subnet
- VLAN 333 and subnet is 10.0.0.0/16, DFG 10.0.0.1
- VLAN 444 and subnet is 10.90.0.0/23, DFG 10.90.0.1
- Both VLANS have been configured to see each other
- Created a Trunk port that is a member of VLAN 333
- Looking to use Trunk port as an uplink port between the Layer 3 and Legacy switch stacks

DUMB SWITCH

- Dumb switch has no VLAN just 1 flat subnet of 10.0.0.0/16
- Flat network is 10.0.0.0/16, DFG 150.120.123.33 (Issued by ISP on port uplink for DHCP requests/IP Helper)

Question

Does the DFG of VLAN 333 need to match the DFG of the legacy switch before uplinking ?
0
please check this message i have received it on our Cisco switch 3850
%SW_MATM-4-MACFLAP_NOTIF: Host 6c4b.9022.14cf  in vlan 220 is flapping between port Gi1/0/19 and port Gi1/0/20 ,
Dose this message indicate that i have a L2  loop or just to inform me because no ports go down and up again?
0
Build an E-Commerce Site with Angular 5
LVL 19
Build an E-Commerce Site with Angular 5

Learn how to build an E-Commerce site with Angular 5, a JavaScript framework used by developers to build web, desktop, and mobile applications.

Hi

I have a Cisco WS-C2960X-24Port POE switch which is being used to connect Ruckus wireless access points.
I would like to connect a new access point to the switch .I have now setup the static IP address and subnet mask on the access point by logging into the GUI.
I logged into the Cisco POE switch and please see the show run configuration. On the Port 6, 7 and 8 access points are connected, and they are all working condition.

Now I would like to configure port 1/0/9 with same config as done with other ports (6, 7, 8 and 9)
Please post me step by step to configure port  interface GigabitEthernet1/0/9

interface GigabitEthernet1/0/6
 description *** AP's ***
 switchport trunk native vlan 109
 switchport trunk allowed vlan 91,92,98,109,110
 switchport mode trunk
 switchport nonegotiate
!
interface GigabitEthernet1/0/7
 description *** AP's ***
 switchport trunk native vlan 109
 switchport trunk allowed vlan 91,92,98,109,110
 switchport mode trunk
 switchport nonegotiate
!
interface GigabitEthernet1/0/8
 description *** AP's ***
 switchport trunk native vlan 109
 switchport trunk allowed vlan 91,92,98,109,110
 switchport mode trunk
 switchport nonegotiate
!
interface GigabitEthernet1/0/9
 switchport access vlan 384
 switchport mode access

Any help would be great
Thanks in advance.
0
Hi all

Doing an install 30,000 sq fot facility, going to need small but enclosed racks for the manufacturing areas, minimal openings just to house 1-3 switches.  Most likely will have 1 24 port switch in each area.  Anyone have a manufacturer/resource what I should standardize on purchase from?

Thanks guys!
0
I have a copy of Cisco ACS, ver 5.3.0.40.9 that we use in our environment to authenticate port access in our Cisco switches to our AD controllers to ensure the device attaching is a company asset. Has worked great for years until 2 months ago. New MS patches break the authentication process.  In the ACS server, the message "unknown AD error" is being reported.  Anyone else run into this?  To resolve, we have to back the current patches back out. We plan on rolling out ICE next year.
0
I have a network which currently has the voice and data all on the same network space (192.168.27.1/24). The DHCP server is a Draytek 3900 Series Firewall and the network switch is Catalyst 2960 L series.

How do I setup the 2nd VLAN for voice and get the firewall to issue a different IP (192.168.28.0/24) for the phones whilst leaving the PC's on the original network.

Thanks
Sycamore IT
0
Using this command to add switch  to stack: 2960 stand-alone switch:

switch 1 renumber 4

this was done before actually adding to stack

now when i look at running config or sh switch I have the following:
appears as 2 switches:

L3switch4#sh switch
Switch/Stack Mac Address : b8be.bf73.6500
                                           H/W   Current
Switch#  Role   Mac Address     Priority Version  State
----------------------------------------------------------
 1       Member 0000.0000.0000     0      0       Provisioned
*4       Master b8be.bf73.6500     12     1       Ready

and i have interfaces for 1/0/1-51  and 4/0/1-51     the 4 being the active 1

Just want to understand this behavior ? I'm guessing that when I add it to the 3 switch stack that the 1/0/1-51  switch 1 will disappear? - I gave it(switch4) a lower priority as well to ensure it did not become master. Thanks for helping me understand this.  Why did it create what seems to be 2 switches?
0
We have tried connecting the Ubiquiti Switch 8 - 60W to several of our Juniper EX-3300 Switches and each time we get a link indication light on both devices that lasts less than half a second, then the link fails.  We have tried connecting to edge ports as well as uplink ports with Copper SFPs, disabling POE, setting the port as Access as well as Trunk and nothing works.

By contrast, we have never had this problem with the assortment of NetGear switches we have connected to Juniper Edge/Uplink ports.

Any suggestions, directions, or shared experience would be greatly appreciated.
0

Switches / Hubs

21K

Solutions

17K

Contributors

A switch is a device that filters and forwards packets of data between LAN segments. Switches operate at the data link layer or the network layer of the Open Systems Interconnection (OSI) Reference Model and therefore support any packet protocol. LANs that use switches to join segments are called switched LANs or, in the case of Ethernet networks, switched Ethernet LANs. A hub is a connection point for devices in a network. Hubs are commonly used to connect segments of a LAN. A hub contains multiple ports; when a packet arrives at one port, it is copied to the other ports so that all segments of the LAN can see all packets.