Questions tagged [networking]
For questions about networking in general. Any question about all on topic network devices can use this tag.
523
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How is the efficiency of Pure ALOHA derived using Poisson's Distribution?
Pure ALOHA has a vulnerable time of 2T where T is the transmission time for a single frame. Pure aloha has a maximum throughput of 18% but how is it actually derived from Poisson's distribution?
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VPN compatible with China's firewall [closed]
Some of my colleagues are working from China and we are looking for a compatible VPN provider for my colleagues.
The requirement is to connect to the servers in public cloud providers
Access the ...
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23
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How do you set an A record for any shared host? [closed]
I'm trying to use an A record to redirect my domain to a separate domain that I own. This process has worked fine with DigitalOcean Droplets -- I just add their IPv4 address in the A record and the ...
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input discards on Arista 7124SX-F
im seeing input discards on one of our uplink on Arista SW
if i run sh platform fm4000 interface ethernet 22 counters verbose command it is showing smp0DropPkts which is equal to the input discards.
...
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Does TCP CUBIC reduce window size for an idle connection?
Does the TCP CUBIC congestion control algorithm reduce window size for a connection that has been idle for a time but has not yet timed out? For example, if an application starts sending data and ...
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2
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41
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How does sender find ip address of the destination (in a WAN)?
We need the destination ip and Mac address to send data right? So if I want to send some data to another host on a completely different network, how does the device find it's ip address? (Like in case ...
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2
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73
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What Happens If A Router Added To The Wrong Area Instead Of The Area 0?
Considering This Topology:
Which is a part of the Practical Networking youtube educational channel, we can see three areas.
The teacher said that all traffic should go through Area 0 to keep a Hub ...
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[Mininet/Miniedit]: Routing doesnt seem to work in case of 2 routers
Similar to the question asked yesterday, as a part of an experiment, my network has the following topology for two host machines connected to a router in mininet(on Ubuntu 22.04.02 Virtual Machine)
...
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[Mininet/Miniedit]: Can't get the host machines connected via a router to ping each other [closed]
As a part of an experiment, my network has the following topology for two host machines connected to a router in mininet(on Ubuntu 22.04.02 Virtual Machine)
h1 - r1 - h2
The host Machine 'h1' ...
3
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2
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98
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ethernet switching table is empty | vQFX | EVE-NG
I'm new to Juniper switches. I configured vlan10 and assigned two ports to the relevant vlan.
root> show vlans
Routing instance VLAN name Tag Interfaces
default-switch vlan10 ...
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What is "n6" in transparent architecture (NG-RAN)?
Hello everyone!
I study the NG-RAN logical architecture described in TS 38.401, baseline for NTN scenarios.
I have found the picture of transparent architecture, you see below. I can not find a ...
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Why No Ping When Use Static and RIP in This Network?
I am a learner. I learned somewhere that we could use static and dynamic routing in the network.
I built the simple network shown in the attached picture.
I configured router8 with static routes to ...
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How does each OSI layer get to know the information [duplicate]
This might sound dumb but how do each layer get the information?
To give a context,
Lets say I enter www.google.com, the browser sends a request to the Application layer and then the HTTPs request is ...
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What is Pipe model in MPLS, and for what scenarios and situations is it used, in most simpliest terms?
I know there is Short-Pipe model and Uniform Pipe model. What is the difference between tunneled traffic PHB and tunnel PHB in Short-Pipe model?
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In what situations is MPLS label erased from the top of the label stack in MPLS?
What are other processes that MPLS/IP routers can do with, or to MPLS label stack?
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What issues can rise from web gui config changes then making other changes from the CLI?
I'm using a 9200L Cisco switch
If I make changes in the CLI, then I make changes in the Web interface and vice versa.
Will there be issues down the road with the config file getting corrupt or ...
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Do wiremap testers detect split pairs
I was watching a How-to video on Youtube on wiremap testers and the technician said that wiremap testers detect split pairs among other wiring faults. However, I came across a Networking question ...
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Trace Route RTO in two or more hop but next hop works [duplicate]
Today when I was doing tracert,
in the 2nd & 3rd and also 4th Hop I get RTO but my next hop seems to be reachable. How come it works?
Please answer asap.
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Why is MPLS label added between layer 2 header and layer 3 header of OSI model and not between headers of layer 3 and 4 of OSI model?
Is there a possibility to use any other two OSI model layers' middle positions? What is the basic concept of switching of packets with MPLS on layer 2.5 of OSI Reference model?
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What is PPP and why does it not have a MAC address?
I just wanted clarification on what exactly PPP is and why it does not have a MAC address due to having seen that under a response to a question of how routers transverse packets to their destinations....
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How should edge switches have their routing configured (when there is a mgmt vlan in the mix)
I'm having trouble with a new network topology we are trying to implement onto our environment. The issue seems to be with the switches. The problem is not relevant to this question but for ...
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In determining the Hamming distance, how does one know what the list of valid codewords are?
Hamming distance is said to be the number of bits that differ between two codewords. If two code words differ by a distance of d, then up to d-1 bit flips can be detected.
The example given for such ...
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L2 connection from the simulation network in GNS3 VM to the physical network
GNS3 VM is used to run GNS3 network simulations.
How can I connect from the network in the simulation to the physical network at Layer 2?
For example, create a GNS3 environment with the following ...
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Did I get the network ports correctly?
When we enter a URL (for example https://some-url.com) in the address bar of the browser and press Enter, then (simplified version):
when the browser establishes a TCP connection, it sends a SYN ...
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snmpwalk returns hex-string for interfaces without a description
nterfaces with an actual description are returned as a string, for example the interface with Device1ILO
However the interfaces without a description configured, are returned as Hex-STRING 00.
How can ...
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2
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103
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Connecting L3 and L2 switches with VLAN settings
I have 1 L3 switch with
Static ip - 192.168.0.252
Two L2 switches
Switch A - 192.168.0.250
Switch B - 192.168.0.251
I have created VLANs in L3 switches with 192.168.1.1 and 192.168.2.2 ips abd set it ...
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51
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How does a client end the TCP connection when SYN+ACK is not received after multiple retransmissions? [closed]
I am trying to establish a TCP connection with a server. I added a firewall rule in the server to drop the TCP packets in order to check how the TCP client terminates.
Client retransmits SYN multiple ...
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2
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41
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Are there any ASNs with 0 IP addresses? [duplicate]
Here is the list of all the US ASNs networks ranked by the number of IP addresses: https://ipinfo.io/countries/us
However in the page 10, I can see some ASNs with 0 IP addresses: https://ipinfo.io/...
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Why would TCP ever allow a SYN for a connection in the TIME-WAIT state?
RFC 1122 says this:
When a connection is closed actively, it MUST linger in
TIME-WAIT state for a time 2xMSL (Maximum Segment Lifetime).
However, it MAY accept a new SYN from ...
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How is window retraction a "general" problem when segment length is less than the window scale factor?
In the RFC 7323 there is an example about window retraction:
https://datatracker.ietf.org/doc/html/rfc7323#appendix-F
The text also says this:
This is a general problem and can happen any time the ...
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127
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What are common network debugging techniques?
I set up our company network several months ago. Some weeks ago, we started having some issues, and I want to find the root cause. How do you debug networking problems in general?
My background is in ...
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Public and Private IP address range confusion [duplicate]
class A private IP range (10.0.0.0 to 10.255.255.255)
class A public IP range (1.0.0.0 to 127.0.0.0)
In these 2 public and private IP ranges, the private IP range is also included into the public ...
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43
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Why is congestion collapse from undelivered packets not possible when there's 1 congested link?
rfc 2914 says this:
The avoidance of congestion collapse from undelivered packets
requires that flows avoid a scenario of a high sending rate, multiple
congested links, and a persistent high packet ...
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Why does the TCP rfc say that there shouldnt be an ACK for the left window edge sequence number?
From rfc 9293:
A TCP implementation MAY send an ACK segment acknowledging RCV.NXT
when a valid segment arrives that is in the window but not at the left
window edge (MAY-13).
But isn't RCV.NXT the ...
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246
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Why are TCP keep-alive messages sent with an already ACKd sequence number?
This is what the TCP rfc says about keep-alive messages:
Implementers MAY include "keep-alives" in their TCP implementations
(MAY-5), although this practice is not universally accepted. ...
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12
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How does the client verify its own SYN? [duplicate]
The TCP rfc 9293 says this:
A 3WHS is necessary because sequence numbers are not tied to a global
clock in the network, and TCP implementations may have different
mechanisms for picking the ISNs. The ...
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Ethernet Frame fields and Physical Frame fields
In L2 Ethernet fields we see [Preamble][SFD][src][dst][tag#][ip/tcp data payload] [FCS] [trailer?]
Does the L1 Physical layer contain [IPG 12octets] field or is that part of L2. What fields sit at L1 ...
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How can I connect two servers using static IPs and two laptops using DHCP
I am currently working with two laptops and two servers which I am trying to link together. For this instance, I do not have a network connection and I will be using a switch as I'm isolating these ...
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74
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Customized IPv6 packet with multiple inner data fragments for multiple destinations
I am studying the possibilities of using IPv6 potentialities to design a customized IPv6 data packet that has the following features:
1. Combines many fragments of different data in one packet.
For ...
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Can somebody help me understand this static NAT example
I have the following example:
From my understanding of static NAT the client makes a request on the inside global address of a resource, in this case the webserver. (http://209.165.201.5). The request ...
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TCP and Data field
Need clarification on TCP/UDP DATA field..
Does the Application Layer "Data" go inside the TCP [DATA FIELD] and all of TCP Layer with its Headers sit inside the IP [DATA FIELD], finally the ...
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Question, provisioning divisions of network blocks with differing sizes based on number of hosts required [duplicate]
I was working on this question.
To do this question I used this YT video to help me and I came up with these answers but I wasn't sure about them since there are no answers to the practice questions.
...
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session layer in OSI model
I'm wondering to know how session layer works. In my understanding session layer is to establish active communication sessions between two devices. Based on the OSI layer model, it works layer by ...
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1
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72
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Is there a term for application layer protocols that are responsibilities of network engineers?
In studying network engineering, it is usually taught that network engineers are responsible from physical layer up to transport layer, that is, layer 1-4 only.
Obviously, HTTP or HTTPS are off-topic ...
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How to define packet loss
I found that "Packet loss describes lost packets of data not reaching their destination after being transmitted across a network." So, we can say that it is a portion of transmitted packets ...
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93
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How to properly configure OSPF protocol?
I have this simple 3 router network that I need to configure the OSPF for, when using two routers every thing works fine and i can ping but when I add the third router nothing works
left router
...
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2
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400
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How to solve high ping "spikes" to pfSense when ipSec connections are active?
Background information:
We have latency/freeze problems with our pfSense. To be able to answer the question i will first give some general background information:
We run pfSense V2.6.0 on following ...
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3
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Is `0.0.0.0/1` a valid IP address? If so, what does it indicate?
I know that 0.0.0.0/0 represents a default route.
But I would like to understand what does 0.0.0.0/1 represents? Is it even a valid thing in networking?
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Can't find a device on my network [closed]
I have a device on my network that is at a static address (192.168.3.1). This device is connected to a network switch, that is also connected to the rest of my network. My problem is that I need to be ...
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What's the big deal with "192.168" in ipv4 networking addresses? [duplicate]
What's the big deal with 192.168 in ipv4?
Why can't it be like: 111.473.6946?
Please explain, networking experts.
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