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Questions tagged [networking]

Networking refers to the technologies and techniques that enable the interconnection of devices and applications allowing them to communicate electronically.

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Can't access locally hosted web server on same network

I have set up a Raspberry Pi as a web server on my local network. Everything has mostly been fine for 2 years until today when I went to check the website and found I am unable to access it from ...
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1answer
11 views

Double fronteds to do failover over other servers

I found a problem that I really need help to solve because its becoming difficult. In the picture, I need to access with the browser to https://master.acme.com, it will have two ip's, one in subnet 1 ...
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1answer
17 views

IPTABLES is masquerading packages without explicit rule for that

I am running a simple expirement for validating some NAT concepts with IPtables. I have a Firewall with two interfaces connecting two networks: Network A - 192.168.0.0/24 - connected to eth0 - ...
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0answers
15 views

Amazon EC2 Web Server not Serving Content

I was using an EC2 Ubuntu 16.04 Server instance that was working fine but I had to reboot it briefly and since then I have been unable to connect via HTTP/HTTPS or ping it. I can SSH in and Telnet ...
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17 views

what does curl stuck at “Trying <ip address>” indicate?

We have a fleet of beaglebone boards running Debian 7.9 that communicate with our server (an Azure App Service) over https. From at least one of these boards, most requests to the server timeout. When ...
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1answer
21 views

Interface with static IP that answers pings, but doesn't route outgoing connections

I have an old Linux computer_1 with 2 network interfaces: wlan0 and eth0. There's no iptables there, but there is the ip command. I cannot install extra software there. I assign eth0 a static IP ...
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1answer
13 views

KVM network bridge: Can't access VM from outside

I have a host machine runing Debian stable and a KVM virtual machine running Windows on that host. I have a networking bridge setup for the VM but I'm unable to reach the VM (ping, connect,...) from ...
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0answers
12 views

Routing troubles on secondary FIB/routing table on FreeBSD

I have a need for a secondary routing table on this machine. I've got everything mostly set up, but I'm having an issue getting the default route working on the secondary fib. In most information I ...
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29 views

Slow docker overlay network between physical sites

Running a docker swarm on the same subnet interconnected on two physical networks via a fibre link. One of them is 10Gbps, and the other 1Gbps. As so: -------------------------------- | | Site A, ...
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0answers
15 views

network issues xenserver vm's

I have xenserver 7.x installed and recently had to replace the Nic. I was able to get the new Nic configured but the problem is the vm's are having trouble communicating with the internet. On the ...
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0answers
11 views

VPN Remote access to esxi [on hold]

So i have got an esxi server and i need to have my client access it from the city over. Its currently behind my firewall (mikrotik) and has a private IP for management on the local network. I have ...
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1answer
37 views

Had cat5e cable and got 1000mbps, upgraded segment of it to cat6, now limited to 100mbps [on hold]

I have a setup in my home that goes something like this: [cable modem] -> [Netgear Gigabit switch UPSTAIRS] -> [Netgear Gigabit Switch DOWNSTAIRS] -> [Netgear Gigabit Switch OFFICE] -> [My PC] Now, ...
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0answers
13 views

Can't access NAS [on hold]

I have a Synology NAS box. I cannot seem to access it. I used to be able to access it from my T Link router. Now, since I got a new router, I cannot access it. However, when I use my MacBook, in ...
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3answers
62 views

If I create my own DNS with a domain name how do I prevent somebody else from copying my DNS?

For example, how does the internet prevent someone from creating their own DNS and creating a copy domain name of "www.google.com" directing traffic from the website on "www.google.com" to the copy ...
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0answers
17 views

Batch script if findstr TTL [on hold]

so im trying to write a little script. It should play a sound if my Phone joins my Network. @echo off :A ping -n 1 xxx.xxx.xxx.xx | findstr TTL && start airsiren.wav goto A The Problem is ...
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1answer
29 views

Hetzner IP Subnet on Windows 10 VM

I have created a brouter (bridge router) on my CentOS 7 KVM Host machine. I am trying to assign an IP from an addon subnet that Hetzner has provided. The following is the working configuration for a ...
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1answer
42 views

Ubuntu 16.04 can't ping from public from outside LAN, but connection works

This is a fairly fresh install that I just got done importing the OpenStreetMap DB using this tutorial: (https://switch2osm.org/manually-building-a-tile-server-16-04-2-lts/) on and was trying to get ...
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0answers
13 views

Fail2Ban with Kubernetes? or any other alternative? [on hold]

-1 down vote favorite I am looking for some tools can auto detect brute-forcing user, and block / make log file itself to notice Sysadmin. I know Fail2Ban can do this kinda job on legacy environment, ...
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1answer
36 views

Alternatives to white listing multiple external ip in restricted network

I have a use case where at a customer site I have to instruct the customer to white list numerous external server ip addresses. Users in the company have to be able to connect to each individual ...
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1answer
35 views

How to resolve dns in multiple name servers?

resolv.conf domain example.com nameserver 192.168.122.54 nameserver 192.168.124.44 Take this as the sample resolv.conf. The scenario is that the DNS tries to resolve in the first name ...
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0answers
20 views

Windows Server 2008 - Strange Network Connectivity (Firewall)

So we had a network outage last week for a few hours and it caused windows server 2008 r2 to be showing 'no internet' with a yellow exclamation mark. The server has 2 interfaces (on same network), ...
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How can I trace an IP address (ipv4 or ipv6) back to my home network? [migrated]

I am trying to see if my Netflix account has been hacked. I can see the IP addresses that are streaming from the account. However, I'm not sure how to trace the IP address to see the source. I'm ...
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1answer
31 views

What is a 4x 10gbe QSFP-QSFP cable?

I was looking for QSFP cables on Ebay and came across a Brocade 58-0000033-01 marked as 4x 10GE even though it has one QSFP connector on each end. I don't understand what this cable is for, will it ...
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1answer
31 views

How to detect packet loss between two Win 10 computers?

I have an issue where an app that is dependent on file locks crashes on Windows 10. The programmers tell me that app is extremely sensitive to packet loss, so I would like to detect what is happening ...
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0answers
25 views

Are those in the same network?if not,why? [closed]

I know the net id of these are not the same, so the two following are not in the same network.Is this right? 165.12.64.0/19 169.12.31.230/19 My teacher told me the two ip above are in the range ...
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1answer
50 views

bond slave interfaces not getting the same aggregator id on LACP

I have a bug on some servers where LACP (802.3ad) is not working. I have on all servers a bonding device bond0 with two eth slaves and each interface is plugged on a different swich, and both switches ...
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0answers
15 views

QEMU host and guest on the same network

I am trying to get my QEMU guest on the same network as my host, I know that when you boot a QEMU image it assigns it a private IP, so I have been trying to create a bridged network. The host machine ...
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1answer
15 views

Forward incoming data on specific port to both local port and external ip

i want to forward all data coming to specific port to local application listing on that port and as well as to external ip. is it possible to do it using iptables or any other tool?
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0answers
18 views

Kubernetes Influx DB - Backend Unhealthy

I am trying to deploy Influx DB on Kubernetes. Using the official Influx DB Helm chart. I am deploying this Helm chart with the following values file: persistence: enabled: true size: 5Gi ...
4
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1answer
65 views
+100

ESXi - Multiple Separate Concurrent Uplinks on vSwitch?

I currently have an ESXi server hosting a PFSense guest which is being used as an internet-facing router. This ESXi server is set up with two vSwitches (each with an associated port group): WAN - 1 ...
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0answers
38 views

I'm a noob - how do I create my own _spf.domain.com so I can include it in my SPF record?

How do I create my own _spf.example.com so that I can include it in my SPF record? I have multiple networks I need to list in my SPF record and this invalidates my SPF record. I need to add all of my ...
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2answers
182 views

Difference between 127.0.0.1 and 127.0.1.1? [duplicate]

In my /etc/hosts file, I have two lines: 127.0.0.1 localhost 127.0.1.1 hostname What is the difference between the two lines, where do I find the host name?
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2answers
79 views

Port forwarding for 100K+ IP's

I need to do port forwarding on my Linux (Debian 8) to intercept packets going through the machine. It needs to be based on source IP, so different ports for different IPs. I've though of using ...
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0answers
17 views

how to create subnet on lan that i want to hide behind vpn [closed]

not sure if this is the correct forum for this but i am trying to do something and im not sure how to go about doing it. I want to place a set of 4 vm's in my esxi server behind a private vpn. I ...
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0answers
25 views

How to forward traffic from internal node to external node using iptables

I've spent the greater part of the day learning about iptables. Here is the scenario I need help with: private-node-1 is connected to private-node-2 using eth0 public-node-1 is connected to public-...
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1answer
17 views

Database Connections Persist After Security Group Change

We've set up a system to send a message to a queue in SQS when there's an outage on a dependency. In order to simulate an outage and test the system, I blocked the outbound port to a database on the ...
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1answer
56 views

Simulate network environment and forwarding packets?

My question might be a bit weird, but here's some background first: I've got a client with devices in their own network with different IPs (mostly 192.168.x.x). From the outside, I connect to one of ...
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1answer
56 views

How to manage an inaccessible remote windows server

I have a Windows server that hosts my applications. The server in question is managed by a third party company. This server is accessible by remote desktop from a jump box. During the configuration ...
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2answers
23 views

Linux routing issue with two nics

I have a Server (SERVER1) with two network interfaces, as shown in the diagram. I have another Server (SERVER2) from which I am trying to connect to SERVER1. When I connect to eth0 (10.0.0.124) I ...
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1answer
40 views

Receive multicast frames from different subnets

I'm trying to receive on my LInux box multicast frames from hosts on a different subnet. For the experiment, and ONLY for this experiment, i have two machines connected through a network switch: ...
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0answers
22 views

Does a Google Chromecast use layer-2 (MAC address) discovery on a LAN? We want to cast over Ethernet

I'm the SysAdmin for SMB and we are using Google Chromecasts on TV's in the office for various things (brief meetings, office parties, etc). I was under the impression that these work off of layer-2 ...
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0answers
18 views

Bridge is loosing packets

I have a Router running OpenWRT 15.04. The Router has a dedicated Wifi Radio, which is internally connected to eth5. I am running 2 Wifi Networks on that Dedicated radio, one is running on vlan 3. So ...
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0answers
14 views

How to diagnose / fix losing connection to local Server 2012 R2?

I have a very annoying problem in which everything works like a dream, and one application is hanging, almost certainly due to lost file handles. The network is exemplary; certified Panduit, server ...
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1answer
30 views

Opening a Hyper-V VM to the Outside World

I created a Windows Server 2016 virtual server using Hyper-V Manager on the host. I have several virtual machines. The host computer has 2 network connections to our main switch: a dual bonded 10G ...
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0answers
16 views

Using non-FUJITSU 10Gb Ethernet Cards in FUJITSU servers

We are currently trying to upgrade old servers to 10Gb connections. The servers in question are: PRIMERGY RX200 S6 PRIMERGY RX300 S5 Our FUJITSU partner told us that there were no cards available by ...
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1answer
25 views

How to run a program in the context of a VRF in Linux

I have created a VRF and I have added interfaces and routes to my VRF. My VRF is as shown below. My VRF is names wan1: [root@host ~]# ip route list vrf wan1 default via 12.12.12.12 dev enp1s0.4025 ...
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1answer
46 views

New computers can't connect to the network

Good Morning, We have a business environment in which we have 3 Cisco 3850 PoE stacked and We manage our DHCP through our DC server. Last weekend our UPS had a failure and switched off all outputs, ...
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1answer
22 views

How to ping from a physical machine to another physical machine's VMware network VMnet8?

I have a physical machine (first pm) which has VMware Workstation 14 Pro. By the configurations and settings I can ping among all the machines and any internet address from them as normally. However, ...
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0answers
10 views

How to “forward” or share whole network into a host in Vagrant setup?

I have setup: Windows (host) => Centos 7 (Vagrant 1.9/Virtualbox 5.1, guest) => Docker. I have docker0 network in the guest machine. docker0: flags=4099<UP,BROADCAST,MULTICAST> mtu 1500 ...
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0answers
32 views

No route to host, not able to ping [migrated]

I am attempting to reach the admin web page of a router connected directly to my laptop via Ethernet cable. The router (a TP-Link WR700N) is brand new, just taken out of the box. It is plugged in and ...