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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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How to find which MPIO path is being used for IO?

We were experimenting MPIO with our Storage array. We saw the Get-Iscsisession and Get-Iscsiconnection cmdlet to find the paths created. But during IO ,i would like to know which path has been used. ...
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0answers
6 views

Linux LAN not connecting [on hold]

I got a new router. Windows connects to it without problems. Linux can't connect to it using IPv4. It broadcasts DHCP but no server responds. IPv6 is working. I need IPv4. Any help much appreciated.
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0answers
8 views

Libvirt: Port-forward from guest to guest

TL;DR: I want to access port 443 at the host IP address from within a VM on the same host, and have my request forwarded to a different VM on the same host. I am using Libvirt to manage some VMs ...
0
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1answer
15 views

Handle traffic over network bridge

I have 2 network, LAN1 connected with some hosts and the second LAN2 with proprietary Hardware, similar to PLCs. This kind of PLC is connected via Ethernet and is used for home automation (ie Light ...
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2answers
14 views

Lost connection to main interface after brctl addif

I was setting up a server recently, and I was supposed to assign one of the public IP available for the server to a KVM guest. The server have the following setup: eno1 - main internet connection of ...
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0answers
12 views

Blended Bandwidth with multiple carriers How to configure IP address

I have seen many colocation companies offering something called "Blended Bandwidth" and that makes me wonder how do they do it? Here is my example. If I would get two internet services, from ISP-A ...
2
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2answers
34 views

How to Configure 2 IP Address on Same Network Interface to Allow Specific Ports to be Accessed by Specific IP?

I have 2 IP addresses on the same network interface: 192.168.1.100 & 192.168.1.101. I want to be able to access SSH via 192.168.1.100 and HTTP via 192.168.1.101. I'm using Debian 9.8 and firewalld ...
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0answers
14 views

VirtualBox windows 10 host to Ubuntu 18.04 guest host-only adap but no communication [on hold]

ipconfig from windows 10 host Ethernet adapter VirtualBox Host-Only Network: Connection-specific DNS Suffix . : IPv4 Address. . . . . . . . . . . : 192.168.56.1 Subnet Mask . . . . . . . . . . . : ...
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1answer
29 views

One machine's network usage can increase latency for everyone sharing the same ethernet switch

I'm managing an office network of about 20 computers, which all share a common ethernet switch (unmanaged), which is then connected to the ISP's cable modem/router combo. Every now and then someone ...
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0answers
25 views

Is my NFS mount actually using async? Diagnosing very slow response time

I have the following NFS mount: server:path /mnt/path nfs rw,hard,intr,nfsvers=4,async 0 0 Recently, packet routes to the server started taking 60 ms instead of <10 ms, but this is still quite ...
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0answers
17 views

IP assignment task [duplicate]

I have an assignment, but I can't figure out where I should start. I'm not asking anyone to solve my homework, but I've tried to read up on network layers to assign IP addresses etc. but I can't seem ...
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0answers
31 views

Expose each docker instans with it's own ip-number

I have a server on my network and I would like to use that one to pretend to be many different servers. The physical pc is running a Ubuntu server and when connected to the network the dhcp server ...
0
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1answer
23 views

What iptables rules should I add first in the 'ruleset'?

I am setting iptables up the following way: sudo iptables -P INPUT DROP sudo iptables -P FORWARD DROP sudo iptables -P OUTPUT DROP and I want to add the following rules: sudo iptables -A INPUT -m ...
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0answers
18 views

can't ping my own IP address (interface with multiple IP Addresses)

I have a server where one of its interfaces (eth2), has multiple IP addresses: $ ip addr show 1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN group default link/loopback 00:...
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0answers
12 views

Do docker and podman iptables rules conflict?

I've installed both Docker and Podman on the same machine. Is that my first problem? Maybe. But my goal is run both and I'd like to continue anyway. My problem is this: there seems to be an iptables ...
0
votes
1answer
42 views

Using iptables to block connections from local network

My network's DHCP address range goes from 192.168.0.100 to 192.168.0.199 and it's subnet mask is 255.255.255.0. I want to use iptables to DROP any INPUT (and OUTPUT too, if possible, as I don't want ...
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0answers
25 views

Slow file transfer speed untill network service restart in CentOS

I have a Windows Server VM which connects to my Storage VMs running CentOS in another Data Centre over SFTP and FTP. The uplink between the servers are all 10Gbps and more and both VMs are ESXi ...
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0answers
19 views

Postfix - can't recieve emails from external domain (Ubuntu 16.04)

Good morning! I have a bit common problem, but I haven't found any solution yet, after reading really a lot of forums and tutorials. Shortly: I want to send an email from external domain to my server,...
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0answers
39 views

How easy is it to listen to traffic between servers on a public cloud (in the same data center)? [on hold]

Let's take the following examples on the Hetzner infrastructure (Hetzner is not necessary for the larger question, it just happens to be a relevant example, where servers are not given a private IP, ...
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0answers
3 views

Machines under custom network in VMware Fusion can't see each other's HTTP server [migrated]

I configured a network in the VMware Fusion Preferences Panel which looks like this: And then I created 2 virtual machines with CentOS 7 Minimal: docs 172.16.227.129 gerrit 172.16.227.130 Now on ...
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1answer
27 views

Ethernet cable only works A to B, not reversed. Why?

A custom ethernet cable with both connectors wired as T568B only works when connecting A to B, but not reversed, i.e. when switching ends and connecting B to A. A is a Mac, B is a 1Gb TP-Link ...
2
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1answer
18 views

why the ping value different from the mtr?

Why the ping command's output value is different from the mtr command ? I am curious。 ping: about 0.5ms mtr: about 2.3ms
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0answers
11 views

Automatically change docker networks addresses

Recently I run into a problem with Docker and networking. I needed to change the default address pool for Docker networks to be able to allocate more networks than the default. I did this adding "...
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0answers
14 views

Must ssh into server and ping to revive connection on 2nd network card

have a file server, call it a NAS - it is running sshfs ssh, samba and an ftp server. NAS is connected to a wireless network and a separate wired network. If a client on the wired network connects via ...
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0answers
5 views

Raspberry Pi WiFi hotspot - Assign address from Wireless network IP range to eth0 [migrated]

I have hostapd and dnsmasq running on a RPi which I have configured to broadcast a local wifi network and assign connected wireless devices an address in the 192.169.1.x range. What I want to achieve ...
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0answers
10 views

Network switch extension [closed]

In our LAN all the switches were CISCO Switches only. one CISCO WS-C3750X-12S-E switch is configured as l2 and other were all CISCO 2960 swithes , nearly 190 switches. Ex. CISCO WS-C3750X - CISCO 2960 ...
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0answers
9 views

Multihomed Ubuntu 14 using “internally optimized routing”

I have an Ubuntu 14 server which is multihomed with two identical 1Gb network cards. The physical subnet routing is handled by another department. As such, when I want to add a new machine (or NIC) ...
0
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1answer
45 views

How to restrict external access to ports exposed by Docker containers, while still allowing links to work?

I have a couple services running on a machine in docker containers that need to be available to a specific IP address, and need to be available to containers with links (as defined in a docker-compose ...
0
votes
1answer
43 views

No local network [closed]

I have had this issue for a long time. All my devices (Raspberry Pi 2, Linux PC and a windows computer) return the public IP instead of the local IP after I write ifconfig/ipconfig. I don't think that ...
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0answers
23 views

static ip configuration fails seeming identical to dhcp configuration

I'm running Debian vserver and I would like to switch from it using dhcp to using static ip address assignment instead. I have changed /etc/networking/interfaces from the former to the latter ...
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0answers
11 views

Is it possible to configure site to site VPN with Cisco ASA 5505 sitting behind another router?

Due to limitations with my Internet/Static IP provider, I am trying to set up a VPN where my Cisco ASA 5505 is sitting behind a Fortinet router (which has the static IP), and connect to another Cisco ...
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4answers
108 views
+300

How to show realtime traffic on each virtual network interface?

I have a dedicated server with a few virtual network interfaces, each mapped to a public IP address. How can I monitor the realtime traffic (in packets/s or Mb/s) of each of them, ideally on a single ...
1
vote
1answer
30 views

Linux/Windows - how do you detect being plugged into somebody else's router?

Say you have a Linux-based KVM server, running Windows guests. This is connected to your own router (pfSense or VyOS). How do you detect changes in the network connectivity, and take action as a ...
1
vote
1answer
24 views

Assign External/Public IPs to VMs in OpenNebula (Open vSwitch)

I've read multiple posts asking the same question, on KVM and open nebula forums and in general virtualization ones but have only found partial or bogus answers. Some Info: Objective: Be able to ...
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0answers
29 views

Does Ubuntu 18/Linux respect the order of DNS servers?

Does Ubuntu/Debian (or Linux in general) respect the order of the DNS servers? Let's assume clean installation of Ubuntu 18.04 In Ubuntu 18, you can setup the DNS servers like this: Aka does it take ...
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0answers
21 views

How to delete a docker network that does not exist?

I have a docker swarm configuration with 3 nodes. There is a network that sits on only one of the nodes. On that particular node, docker network ls shows the network, docker network rm [network-id] ...
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0answers
23 views

Client (192.168.1.4) should access server (192.168.2.8) application like IIS/XAMPP/APACHE etc. Network Map Below [closed]

Network Map Attached Please suggest what configuration required, I am new in Networking.
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2answers
45 views

Including external config files to dhcpd config

I am setting up a dhcp server on RHEL where some of the entries in the file are generated at a later stage and may be regenerated often. I was looking at the dhcpd config guide and the include ; ...
1
vote
2answers
43 views

Why is transmission time considered as “useful” time while calculating efficiency?

The formula for efficiency = (Transmission time) / (Transmission time + 2*(Propagation time)) for stop and wait protocol. Reference Can anybody tell why Transmission time is in the numerator because ...
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0answers
17 views

How to force traffic replies on different interface

We have computer A and B. A has nic1 and nic2, B has nic3 and nic4. Traffic initiated from A should leave at nic1 and enter at nic3. Reply traffic should go from nic4 to nic2. System is linux. The ...
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0answers
12 views

tc match IPv4 fragment offset

What is the correct Syntax for matching Fragments that have and Offset > 0 in tc? I have tried: ... u32 match u8 255 ff at 7 flowid 2:1 But to no avail
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0answers
14 views

OpenLDAP password reset

So, i would like to achieve procedure of password reset in OpenLDAP. What I did: OpenLDAP server, following guide from ArchWiki: https://wiki.archlinux.org/index.php/OpenLDAP LDAP authentication, ...
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0answers
16 views

Changing MTU in CentOS 6 DHCP server

I have a CentOS 6 server acting as a router with DHCP for my network. I need DHCP to tell all my devices to use MTU 1492 (instead of 1500). I already tried adding option interface-mtu 1492; in ...
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0answers
29 views

Does macOS use NetBIOS?

Do the latest versions of macOS use NetBIOS (port 139) by default? Or is that a Windows-only protocol?
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0answers
22 views

Multicast UDP traffic flow in the distribution layer using VSS

We have a campus with 2 different building with few floors on each building and 100's of systems in different VLANS at each floor. At the Access layer we have Layer 2 switches at each floor connecting ...
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0answers
11 views

Restricting network discovery through VPN

I have an issue in which I have a network of systems connected on an internal network that communicate system status to a gateway system. The gateway system is running a node.js webpage accessed ...
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0answers
44 views

Can I turn a computer into a network switch/router?

I have 3 computers that I want to connect via 100Gbe network connections. 2 of the computers/servers are equipped with Mellanox ConnectX-4 single adapters and one computer is equipped with a dual ...
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0answers
31 views

Unable to connect to my winsock server using external IP

When I try to connect to my simple winsock server using my localhost/LAN IP, the connection is established with no problems. However, if I attempt to do so using my external IP, I keep getting ...
1
vote
1answer
26 views

getting error from ubuntu command line when trying to access samba windows share

We configured Samba at our Ubuntu 18. But at Ubuntu cmd prompt, we type: smbclient //windowsIP/Users/myUserName -U myUserName ..and then get error: "NT_STATUS_BAD_NETWORK_NAME" However, ...
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0answers
28 views

Communicating VM with a Router

I have a VM with 2 Virtual NIC, the first NIC has been assigned IP for communication in our ring network the second NIC has been assigned VLAN 809 and has IP: 172.32.17.10/16 . The server with this ...