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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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How do I know if I need a layer 3 switch?

We currently have a flat network with a bunch of unmanaged switches. I would like to use VLANs to segregate certain users like guests and I would like to use 802.1x. However, I'm not sure if what I need is a layer 3 or a level 2 switch. From what I…
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What's the difference between a switch, a router, and a modem?

What's the difference between a switch, a router, and a modem?
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How do I ground a network switch?

I read in a lot of places that it's necessary to ground networking equipment. In a small SOHO environment where there are, say, 4-5 systems and each system is grounded, is it also necessary to ground the network equipment, that is, the network cable…
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Why do rack switches have their ports on the front?

I've ordered some rack hardware from Dell. A 42U rack, a 3U EqualLogic SAN, two 1U PowerConnect 5424 switches, three 1U PowerEdge servers, and some other stuff such as a tapedrive, firewall, UPS, etc. Since I have little experience with racks I…
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Power loss at company

Property management at my organization has informed me that our building will be losing power for 4 hours tomorrow. I need to be prepared for this event (we're a small organization, i'm young, therefore I am I.T). What sorts of things do I need to…
user8539
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What's the difference between a bridge and a switch?

I can't find any authoritative source that can concisely explain the difference between a bridge and a switch. As far as I can tell, most devices commonly referred to as "switches" fit the description of "bridge" as defined by the IEEE 802.1D…
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How many network switches can I daisy chain together

We have a number of custom computer systems that need to be networked and temporarily installed around a football stadium - each computer has it's own network switch. These computers all need to be networked to a central computer. Up to this…
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Phones on some switches cannot complete DHCP process

Background I have a Windows DHCP server (Server 2008 R2) handing out addresses for several scopes. One of those scopes is for some Mitel IP Phones. The phones are configured to use dhcp option 125 to get configuration information. When a phone…
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Improvements for small business network?

My question is more-or-less a newer version of this 3 year old question: Small Business Network Switches/General network configuration Summary Everything is Gigabit and we don't have any real complaints about network performance. My real question…
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What would cause SIP traffic to be seen going into a switch but not coming out?

Background I have been struggling to get my SIP phones to register behind a brand new router and switch in our brand new office. Our PBX is hosted offsite. I have worked with our provider to attempt several different approaches. We have tried…
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Is a Network Switch IP-Aware?

I have some very trivial basic questions about networking, but I find varying information on that, so I just wanted to settle this. As far as I understand a Network Switch handles traffic "intelligently" in the way that it only propagates packets to…
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How do you keep track of what's connected to your switches?

Currently we manually document the connections to the ports of our switches. Of course, maintenance is a chore, and the documentation is out of date as soon as you save it. Are there any tools for querying switches, preferably via SNMP, that can…
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Virtualization - Ten 1Gbps links or one 10Gbps link? (Performance)

I have a machine that has several VM's (5) and 3 physical networking cards (with each 2 ports), with a total of six 1Gbps ethernet ports. I have a SPF-capable switch, having a total of 48Gbps bandwidth and a 10Gbps SPF link. The server has also one…
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Are network switch data transfer speed limits per port or per device?

When network switches report speeds of say 100 Mbit or 1 Gbit, are they referring to the maximum speed per Ethernet port or is this the physical limit of the switch on all ports? Say for example two users on a network are simultaneously transferring…
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If you turn on spanning tree, how do you know there is an issue with your network?

I have been learning about spanning tree protocol (STP/RSTP/MSTP) and was wondering, once I turn it on and it's protecting against for example network loops, how do I know there is a network loop? I suppose in most cases it would be obvious, because…
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