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Questions tagged [switch]

a device that bridges network segments, operating at the OSI link layer level.

Switches (in the context of this site) are devices with multiple network ports, which allow interaction between all devices connected to these ports.

Basic switches operate at the data link layer level (in TCP/IP networks) and forward packets based on the link layer address in the packet headers. They are different to hubs in the way that hubs generally broadcast incoming packets to all other ports, whereas switches keep tables of link layer addresses they have seen at specific ports and only forward packets to the relevant ports. Basic switches are also known as layer 2 devices.

Higher grade switches can include functionality at higher layers of the OSI stack. This can range from IGMP snooping (for multicast support) and VLANs through to NAT, VPN, firewalls or even application layer functionality (web caching or proxying). Such switches are known as multilayer devices.

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Layer 2 vs Layer 3 switches

I am a bit confused on when I need and should use a layer 2 or layer 3 switch. In the corporate network we have Aruba 3810 core switches, and all the access switches are HPE 1950 24/48 PoE+. We have 7 vlans, IT mgmt, workstations, machines, wlan,…
kmd
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Calculating backplane capacity of a switch

Why is it that people always say that for a switch with ports in full-duplex mode you need portcount times bandwidth times two for the backplane capacity? Let's have an example. Take a 4-port 1Gb switch. Obviously full-duplex since 1GbE doesn't do…
Marki
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What is an "FX port" in the context of a switch?

Looking at this switch datasheet, the concepts of "FX port", "FX switch" and "inline FX" crop up. (The obvious Google searches are not really helpful.) What does FX mean in the context of a network switch?
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Finding (and stopping!) Rogue Devices from HP Procurve

We seem to have a problem with rogue devices on our network. From DHCP (on Win2003), I can see names of devices that are clearly not ours. From the name, I suspect it's a wireless AP (WGR614 looks like a Netgear to me). I can't ping it now, but I…
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Architecting your network when you run out of VLANs

This is an entirely hypothetical question, I'm not in this situation now. What happens to your VLAN topology and routing if you run a multi tenant network and you have more than 4096 customers? Do you have to start "zoning" your network at the…
SimonJGreen
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2 ethernet connections between two Switches

I'm setting up servers at our new office and I brought a spare managed switch with 2 Gig ports to run all of our phones(VOIP) and workstations. Now for the servers I've got a separate gigabit switch(not managed). Will there be any difference if I…
Jacob
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Is it possible to find out what gateway is available on a network without prior knowledge?

A colleague and I both presumed this was a clear "no" but, admittedly, our networking knowledge is limited. Is it even possible that, without prior knowledge of the network configuration (i.e., no DHCP or static IP configuration handy), you could…
Belmin Fernandez
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Is there a network switch with a web interface that reports bandwidth use per port?

I have a number of network enabled devices in the office. I've always wondered how much bandwidth each one is using. I happen to have a 16-port gigabit switch that is dying, so I was wondering if I could replace it with a slightly smarter switch…
Christopher
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Linux Router Problem

I have a Linux based router with four interfaces (each with its own private subnet). When I directly connect a device directly (i.e. no switch, just a patch cable) to one interface and another device directly to another, as below, then the router…
Bryan
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How many switches can be stacked/interconnected?

I would like to know how many switch can be stacked with fiber channel to get a best transfer rate between computers. I have 200 computers connected to 12 3Com switches. All switches have two fiber ports. Is the best way to have fiber backbone…
Jojo
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Cannot ssh into cisco switch: Invalid key length

For some reason I cannot ssh into a Cisco Catalyst C3750 Switch. This is the error message, that I get: ssh_dispatch_run_fatal: Connection to 192.168.7.6 port 22: Invalid key length This is the SSH config, that I am using: Host 192.168.7.6 …
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Does bonding 3 1G NICs into one make a 3G NIC?

For example, I have 3 NICs (1GB) and make a bonded NIC. Do I get a 3GB NIC? Should I connect these 3 NICs into 1 switch? If one NIC dies, do I still have the network between server and switch alive? Or should I connect each NIC to 3 different…
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How to configure a MikroTik hAP ac lite router as a Layer 2 switch?

Here is an overview of the network topology: Both the Fritz!Box 7340 and MikroTik hAP ac lite router currently act as DHCP servers, effectively splitting the network in two LANs. The MikroTik router was also configured as a bridge for the…
Serge Stroobandt
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Gigabit uplink versus regular switch port

I have a 10/100/1000 24-port + 2 mini-GBIC ports switch which I have to link to other switches. Unfortunately, on the other switch all the mini-GBIC slots are taken up, so all I can do is link them together using a regular Ethernet port (which is…
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I have a Cisco Catalyst 2940 and want to connect to it via the network. How to find its IP address?

Since my computer has not serial port, the serial cable is of no help. Does the Catalyst 2940 acquire an address via DHCP? At least my DHCP server doesn't show any address which has been requested recently. Maybe the Catalyst has to be reset first?…
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