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'm looking for some help re-configuring my home network. Here is current setup:

Comcast cable comes into data enclosure in garage wall to a 2-way Splitter. One coax goes to Gateway in my office. Patch cable out of Gateway to a switch beside it which connects my desktop and network printer. Patch cable from this switch to the wall jack backfeeds back to the data enclosure in the garage. Patch panels in the data enclosure connect to small switch in the data enclosure to provide network to other jacks in house.

First, I'm planning to ditch the Comcast Gateway and go with my own modem and router. I want to add a Ubiquiti Cloud Key Gen 2 Plus and eventually a couple of security cameras as well. I'd like to centralize things a bit more instead of going to my office and then backfeed to the data enclosure before distributing to the rest of the house. Unfortunately, there isn't room in the data enclosure for the router, modem, etc. and even if there was, I'd be concerned about the temps. It can get pretty hot in the garage (90F+).

The room directly above the data enclosure in the garage is a storage room with heat and A/C. Perfect location for the network equipment. And it has a knee wall I can get behind and access the cables going down into the garage.  But I'm not sure how best to proceed.

There are 17 Cat5e cables coming into that data enclosure in the garage, 7 from top (upstairs jacks) and 10 from bottom (downstairs jacks). There appears to be enough length on the …
0
Learn SQL Server Core 2016
LVL 13
Learn SQL Server Core 2016

This course will introduce you to SQL Server Core 2016, as well as teach you about SSMS, data tools, installation, server configuration, using Management Studio, and writing and executing queries.

On Cisco core switch 3850, I need to get a list of end devices IP address and it associated port on the switch
0
I have a 6 stack of cisco 3850-24XU switches. I need to move 2 of them about 200 feet away in another data closet, but I would like to keep them part of the stack.

Is there any way to keep them part of the stack.  I read online that there might be an stacking module that uses fiber cables?  Or is that only for the 2960X models?

Any advice would be greatly appreciated if there's a way to do that.
0
I am using PRTG to monitor my network.  I have installed newer cisco 2960X switches, and for some strange reason, the switches are giving me these error messages.
At least PRTG is reporting the data as an error.  I have attached the picture.  Does anyone know what the current should be and what the voltage should be, as I might need to change the current ranges.  Currently I'm getting a reading of 5.40mA and 3.33V.  Does anyone know what the healthy range should be?

health
0
I am replacing a Cisco 2960 switch with a 9200. After copying & pasting the run config from the 2960 the interfaces are missing the following commands;

srr-queue bandwidth share 1 30 35 5
priority-queue out
mls qos trust device cisco-phone
mls qos trust cos

I also see that in our AUTOQOS policy-map for our Cisco phones that the 'police...….' configuration line detail has not pasted across

I am wondering if these commands are handled differently in the 9200 and have to be reconfigured accordingly.

Expert advice on this would be greatly appreciated.
0
We have a switch that it's log is being flooded with the described message above in the subject line. How do I find out what port is causing this issue? Or how can I stop this from happening?

Info: This is a HP-Switch 2510a
0
Hi,

here my project : Migrate Fortigate VM64 v5.6.8 build1672 (GA) to a Fortigate 500e v6.0


The Fortigate VM64 is installed inside a Vcenter ( 4 ESX) with different Vswitches.
Physically the ESXs are on a FC SWITCH with different VLAN.

Here the configuration :

fg1So I think I should do that before migrate :

-Upgrade FG VM64  to v6.0
-Copy the FG VM64 config and adapt it for the FG 500E
-Plug a cable between the FC SWITCH (with the good port and vlan) to the correct interface on the 500E.
-Mount the same interface on the 500E (with the good vlan  and should be the same from the FG VM64)
-Turn off the old interface on the FG VM64
-Test
-Repeat for each interface

BUT, I think I missing something on the vcenter, any ideas?
0
We are planning to deploy Citrix VDI with multiple master images based on functions as we are in health sector and  but we have  got multiple VLANs (subnets) on edge switches in networks.
Please find the attached network diagram

So please advise, how can we proceed ? Where VLANs should be created for VDI machines, VM images and Client machines.
Network-Design.png
0
I had a recruiter asking me if I had experience with Juniper routers and switches. I don't. But I do have quite a bit of experience with the Juniper SRX firewall. I wondered - is the "set..." syntax of the Juniper SRX firewall the same type of commands (or in some cases identical) to what used in Juniper routers and switches? Inquiring minds want to know.
0
Hi, I have 2 separate physical sites (data centers) connected by a L2 ptp dark fiber link with L3 capable switches (Cisco Nexus) at each end. I am trying to decide whether to use a separate transport VLAN interface SVI or "routed ports". Each site would have its own separate Data VLAN with devices in it that would need to communicate with each other, intra-vlan (same site), and across the link to the other sites VLANs. Another area of concern is if I use a L3 "routed port" with static routes to direct the traffic from each end, will the routed port work within a vPC configuration on the Nexus (pair) because it will be an orphan(single) port to the vPC domain ?
0
Learn Ruby Fundamentals
LVL 13
Learn Ruby Fundamentals

This course will introduce you to Ruby, as well as teach you about classes, methods, variables, data structures, loops, enumerable methods, and finishing touches.

We have a Cisco 6509E chassis as the core of our network.  We are trying to run our FOG (Imaging software) server and we are finding multicast is not working through the switch.  We tested this by plugging the server into a variety of other switches that bypass the core and multicasting works perfectly.  I am unsure what settings could be different as I have compared IGMP Snooping and the portfast settings with the switches that work when the server is plugged into them.  

Any ideas?  It is running SUPT2XL as the supervisors running 15.1 on them.
0
In layman terms what does a Layer 3 switch bring to the party as opposed to Layer 2? Is it really needed?
0
Access-List a L2 Switch

I would like to know if we can apply ACL on L2 Cisco switch  based host IP address as well as on Host IP address + Port number.
An Example will be more helpful

Thank you
0
Can anyone point me to a checklist for hardening
of Moxa switches?
0
Hello all.

Could someone advise how to run a command within a Cisco Switch to display what is physically connected to each port?  Our client currently has 3 switches and I would like to create a layout of each switch and what is physically connected on all 48 ports.   I do not know if this can be easily done so help is needed.  Specifically is there a way to tell if its a PC or a Mac or if it can display something to show what the device is in what port?
0
Hi all,

I have a CISCO 3750x, with some vlans created, now i am connecting a Cisco SG-200 to it, how can i have it see the vlan's i created on the 3750 and the devices to communicate properly?

Sorry havent worked with the SG200 before, so kind of unfamiliar!
0
We have a number of Cisco switches at a location that include VLAN 5 in their configuration, I feel that this is a legacy VLAN trunk and no longer in use. Is there a way I can be certain it is not being used prior to removal?

 - A sh VLAN brief indicates that no ports are assigned to the vlan

- sh int trunk indicates;
Port        Vlans allowed on trunk
Gi0/1       5,10,100,200,254

- #sh int vlan 5 sum does not show any activity

- sh int vlan 5  indicates - Vlan5 is down, line protocol is down

- int vlan 5 is configured as following
#sh run int vlan 5
interface Vlan5
 ip address 10.30.5.250 255.255.255.0
 no ip route-cache
end


Is there anything else I should check before removing the VLAN/interface?
0
Hi,

Recently had a broadcast storm we found it by running sh int and the port with errors we shut down and the storm stopped. In trying to research what other steps we could take, came across the command below and it reported multiple ports below including the one below with receiving broadcasts, is that normal or is it something we need to look at and address.

 Also any general advice of commands we can run to check for broadcasts on our networks

show interface | include (.*Ethernet)|(.*broadcast)

GigabitEthernet3/0/47 is up, line protocol is up (connected)
  Hardware is Gigabit Ethernet, address is f8a5.c5bd.ab2f (bia f8a5.c5bd.ab2f)
     Received 1071365 broadcasts (517836 multicasts)
0
Dear Experts, we are configuring a new network of new office in next week and have some questions about security:

- How to prevent "rogue" DHCP servers in network?
- How to prevent "rogue" Wireless Access Point in the network? For example: my office's wifi network is "ABC.com" => we'd like to prevent the other SSID "ABC.com" from users' APs?
- Can we prevent ransonware in some network levels?

Our infrastructure is:
- 2 x Firewall Sophos XG310
- 2 x Core switch Cisco 3850 (will be DHCP servers for 20 VLANs)
- 30 x Access switch Cisco SG220 and SG350
- 30 x Wireless Access point Unify AC AP PRO
0
Exploring SharePoint 2016
LVL 13
Exploring SharePoint 2016

Explore SharePoint 2016, the web-based, collaborative platform that integrates with Microsoft Office to provide intranets, secure document management, and collaboration so you can develop your online and offline capabilities.

MAC FLAP  ?

Aug  7 10:33:42 EDT: %SW_MATM-4-MACFLAP_NOTIF: Host 6045.cb5d.e7d4 in vlan 18 is flapping between port Fa1/0/20 and port Fa1/0/41


Aug  7 10:23:16 EDT: %SW_MATM-4-MACFLAP_NOTIF: Host c067.af86.897f in vlan 18 is flapping between port Fa1/0/20 and port Gi1/0/1
Aug  7 10:23:22 EDT: %SW_MATM-4-MACFLAP_NOTIF: Host 6045.cb5d.e7d4 in vlan 18 is flapping between port Fa1/0/20 and port Fa1/0/41
Aug  7 10:23:27 EDT: %SW_MATM-4-MACFLAP_NOTIF: Host 448a.5bbd.964c in vlan 18 is flapping between port Fa1/0/20 and port Gi1/0/1
Aug  7 10:23:32 EDT: %SW_MATM-4-MACFLAP_NOTIF: Host c067.af86.897f in vlan 18 is flapping between port Fa1/0/20 and port Gi1/0/1
Aug  7 10:23:32 EDT: %SW_MATM-4-MACFLAP_NOTIF: Host 448a.5bbd.964c in vlan 18 is flapping between port Gi1/0/1 and port Fa1/0/20
0
Dear Experts, we are testing the new switch Cisco SG350 but could not know how to change the default native VLAN of it?

Can anyone suggest? Many thanks!
0
We are migrating a school district from a Cisco ASA FW (LAN) to a Fortigate Vdom on our WAN. My normal process would be to create unique vlans that would not overlap on our WAN and reconfigure all LAN switches at the school to use those vlans instead of the normal vlan 1, along with any other vlans that would cause an id conflict.  Another method we have used in the past is vlan translation: assigning a single vlan to their LAN switch port and connecting it to our WAN switch on the desired translated vlan. I.E. vlan 1 connected to a vlan 150 port, vlan 10 connected to valn 151 port, vlan 21 connected to vlan 152 port on the WAN switch. Because of some logistics, I am considering the vlan translation approach and would like confirmation my approach is correct or advice on how to configure properly.

The school is using a Cisco Catalyst 4500 switch that will connect to an Aruba 3800 switch.

I am familiar with the Aruba switches more than Cisco. Would I simply trunk (Cisco trunk) a single port to pass the desired vlan to the Aruba switch and on the Aruba switch set the connecting port to tag the translated vlan?

I.E. Cisco:
interface GigabitEthernet1/13
  switchport trunk allowed vlan 1
 switchport mode trunk
 no logging event link-status

interface GigabitEthernet1/14
  switchport trunk allowed vlan 10
 switchport mode trunk
 no logging event link-status

interface GigabitEthernet1/15
  switchport trunk allowed vlan 21
 switchport mode trunk
 no logging …
0
I installed a new Cisco smart switch and the system light is solid, meaning it is using DHCP.  How do I find the IP?
0
My work uses HP Switches and we needed to trace activity from a specific Network Jack.  The problem is we did not know which port on the HP Switch that Jack was connected to.

We did know the client computer's MAC address its IP address.  I was told to plug in the device and then un-plug it and then plug it back in several times.  That was how my team discovered the port on switch was connected to from that specific data jack.


I believe my team used a port trap or something like.  My quesitons are:

1.  What tools on the switch can be used to find which switch port that client device is plugged into?
0
ip route 0.0.0.0 0.0.0.0 null0

I would like to know what is the purpose of ip route 0.0.0.0 0.0.0.0 null0  in this configuration  below

Thank you

Hub(config)#ip route 0.0.0.0 0.0.0.0 null0

Hub(config)#ip prefix-list DEFAULT_ROUTE permit 0.0.0.0/0

Hub(config)#route-map SPOKE_ROUTERS permit 10
Hub(config-route-map)#match ip address prefix-list DEFAULT_ROUTE

Hub(config)#router bgp 65001
Hub(config-router)#network 0.0.0.0 mask 0.0.0.0
Hub(config-router)#neighbor 172.16.123.2 route-map SPOKE_ROUTERS out
Hub(config-router)#neighbor 172.16.123.3 route-map SPOKE_ROUTERS out

Open in new window

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.