Questions tagged [networking]
For questions about networking in general. Any question about all on topic network devices can use this tag.
591 questions
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If Wi-Fi and Ethernet already handle reliable delivery at Layer 2, why do we need TCP's reliability at Layer 4?
if the lower layers are already doing error checking and retransmission for each local link, why do we need transport layer protocols to also worry about delivery? Aren't they redundant?
For example, ...
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Can I perform inter-VLAN routing on a Layer 3 switch using a single trunk cable connected to an unmanaged Layer 2 switch?
My scenario: I have many endpoints currently connected to an unmanaged switch. I want to add Layer 3 switch and segment the network into VLANs, but I'd like to avoid the manual work of tracing which ...
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Wasn't separation of traffic between bridge ports problematic in the presence of hubs?
I know hubs are a thing of the past, but I'd like to know if my reasoning is correct and accurately describes how things worked 30+ years ago. Assume we have a classic two-port bridge, a hub connected ...
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Why would nmap show a port open on an unused IP address?
I work with NAC in my job, and one thing we're noticing is that every endpoint, regardless of what device type it is, shows up as having 1720/TCP open. When I log into the CLI of our NAC appliance and ...
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3 firewalls on a layer-2 switch, 1 acts as a default gateway for all devices
I am currently trying to setup a network madeup of a large layer-2 switch, some computers connected to that switch, 3 Cisco Firepower 1120 ASA Firewalls, and other networks beyond 2 of the firewalls, ...
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How to add a static IP address in my SOPHOS XGS Firewall?
I am new to networking, and I want to create a static IP address for my Sophos Connect VPN. So, previously, it was done by the vendor, not the static IP address setting, but they gave us three ISP's ...
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Pseudo Header In Layer 4
Why we need pseudo header when calculating the layer 4 protocol checksum ?
Because in layer 3 we already have a checksum to calculate only the layer 3 header checksum, and why we also need to ...
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Connect two Fiber Optic Cables using Patch Cord?
Good day! In the attached image, AB fiber segment and BC fiber segment are terminated using LIUs. Data Servers are at Location A.
One way to inter connect AB and BC segments is by fusing a pair of ...
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Checksum In layer 3 and layer 4
I'm little curious about the checksums in the IPv4 header and transport layer protocol.
I have 2 questions:
(1). Does the layer 3 checksum in the ipv4 protocol calculate the checksum of ipv4 header + ...
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MTU & Fragmentation
MTU Specify how many byte we can send through the link
In the Ethernet link the mtu is 1500 byte
My question is :
(1).Can we send a data less then the mtu ?
(2). if I'm sending data with a size 1300 ...
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Bypassing government imposed internet bans [closed]
Problem
Since last year, our government has imposed recurring internet restrictions, instructing ISPs to block all IP-based traffic during certain periods. This leaves residents without internet ...
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Do Extreme Switches need to have ports filled in sequence
I'm having a weird issue with a network switch that I'm trying to determine if it's an actually defective switch. I have an Extreme Branded Switch deployed (ISW8GbP, 4-SPF) with ports 1, 2, 3, 5 and 6 ...
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Use Cellular Data while Maintaining Connection to Offline Wifi Hotspot [closed]
For a project I'm doing, I want to maintain a connection to an offline wifi hotspot. I want to do this so I can interact with the device wirelessly.
I want to also, at the same time, be able to use ...
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183
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Isolate a subnet for Azure SQL server so it is not publicly accessible
TL;DR - How do I isolate a resource in an Azure subnet so that it is not publicly accessible, but is accessible from other subnets in the same VNET?
Apologies if this isn't the correct site; this is ...
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Help understanding a use case to develop a network topology
I am self learning networking and now want to create a simple network topology in containerlab. This is only for a simple test lab. For this I am only using OSPF and BGP. I have came up with a ...
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