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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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What's a good way to handle multiple devices with the same MAC address on one network?

The devices I'm working with come off the production line all set to the same MAC address. I can set each one to have their own static IP, and I'm wondering if there would be a way to connect them to the network at the same time in order to…
Anthony A.
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What happens if you short-circuit a network patch cable?

Today we had some network problems and after some nested-interval trial and error we tracked down a small 4-port hub where someone had connected both ends of a patch cable to the same hub. After removing that, everything went ok again. My question:…
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What is serialisation delay? Why does 10GB Ethernet help reduce it?

In the context of a network switch, what exactly is "serialisation delay"? (I've heard this term a few times.) I've also heard that 10Gb Ethernet (as opposed to 1Gb Ethernet) as a transport technology helps reduce serialisation delay even when the…
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Do switches sometimes need rebooting?

In your opinion, do switches sometimes need a restart? I'm asking this because today our NAS stopped working properly, and was only fixed when we restarted the switch it was attached to.
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Cable management strategy for a small chassis switch

I'm working with a small site buildout that contains a single HP ProCurve 4200vl chassis switch. The data cabling contractor did not provision for any cable management. I'm looking at the rack pictured below and would like some suggestions on how to…
ewwhite
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Are VLANs necessary for my environment?

I'm the new network manager for a school. I've inherited an environment made up of several Windows servers, about 100 Windows clients, 10 printers, 1 Cisco router, 6 Cisco switches, and 1 HP switch. Also, we're using VoIP. There are four floors in…
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Automatic rollout of VLAN (and other) configs to Procurve switches

I've got a pile of switches connecting everything together at our DC, 50 racks or so worth of kit. It's starting to be a problem to login to every single one of them to make configuration changes -- mostly adding/removing VLANs to all the trunk…
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Are VLan's used to split my switch into segments?

I'm trying to plan for the following Small Office network setup: 3x Internet connections Things connected to the port in each colour can only get routed through their corresponding internet port. for example: Internet 1 (RED) - ports 4, 6, 8, 10…
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Is it possible to connect a single NIC to two different VLANs?

I know it is possible to assign multiple IP addresses to the same NIC as long as they are on the same sub-net (e.g. server A can be assigned both 192.168.1.1 and 192.168.1.2). However, is it possible to assign multiple IP addresses that are a…
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Proper method for connecting multiple non-stackable network switches?

I deal with many clients in warehousing and industrial applications who have IT staff or local consultants. Many of these sites are still using a 10/100 Megabit switching backbone... I've managed to get some clients to invest in networking as a part…
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Is my Cisco switch port bad?

I've been chasing a packet-loss and network stability issue for a handful of end-users on an internal network for the past few days... These issues surfaced last week, however the location was struck by lightning six weeks ago. I was seeing 5-10%…
ewwhite
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Why WakeOnLAN frames are sent to broadcast

I'm trying to figure out why wake on lan frames, in the simplest form, are designeted to the ethernet broadcast address (FF:FF:FF:FF:FF:FF) and not to the address of the machine to be powered on. Does it has to do with the network switch internal…
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How to prevent or block other DHCP servers?

Is it possible in a managed switch such as a 3com 4500 or a HP Baseline PWR-Plus type switch to block DHCP from being served through specific ports, or all except 1 port? I have a DHCP server for example plugged in to port 1, I need that to continue…
Scott Szretter
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Cut network cables in Cisco 2960 PoE

We've a Cisco 2960e that services our VoIP phones and other things. I inherited it. The question I have is the cut cables: there are about four network connectors that are cut about 1cm away from the end - making it nothing more than a physical…
Mei
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Admin mode on Procurve Switches

Not being a network expert, I spent some time configuring my network, until I found my mistake: On my HP ProCurve Switch 1810G, I thought that "Admin mode" means whether the administrative interface can be accessed from this port. Well, it means…
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