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

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55
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8answers
50k views

What is “anycast” and how is it helpful?

I'd never heard of anycast until a few seconds ago when I read "What are some cool or useful server/networking tricks?". The wikipedia "Anycast" article on it is quite formal and doesn't really evoke ...
4
votes
1answer
1k views

NFS mount mounted inside another NFS mount disappears randomly

I have quite an odd issue where my nested NFS mounts just disappear randomly from time to time. The fstab entries look somewhat like this: nfs:/home /home nfs rw,hard,intr,rsize=32768,noatime,nocto,...
6
votes
4answers
26k views

How do I force Linux to reacquire a new IP address from the DHCP server?

The environment is Debian, although the answer will apply to all distributions.
0
votes
3answers
51 views

Connectivity between switches using SFP+

My office infrastructure is currently configured with HP Procurve switches. They are interconnected with 10Gbps fibre. All the SFP+ Ports are in use on all the switches. I am looking at buying a new ...
3
votes
2answers
1k views

Winbind/AD: Local users with identical AD usernames

We are getting ready to add Winbind/Samba to some CentOS servers. Identity Management for UNIX is running on our DC, and it's testing well so far. There is one scenario I'm having trouble with, and I'...
1
vote
1answer
2k views

snort complains on local.rules

I just installed snort-2.9.7.0 on Fedora 20, and am getting error when running: % snort -c /etc/snort/snort.conf --dump-dynamic-rules=/tmp Running in Rule Dump mode --== Initializing Snort ==...
2
votes
1answer
42 views

Recover GPO Rights

I messed up at work today, and I've accidentally denied a group (I don't know which one) from read-level permissions. I went to work on delegation for a user for a GPO, and I must have accidentally ...
1
vote
1answer
1k views

Multiple Homed Windows 2008 Server / Windows 7 Client

I have a small Windows 2008 network, with some Windows 7 clients. The clients are both laptops with docking stations and I would like them to communicate with the Windows 2008 server (for filesharing) ...
0
votes
1answer
21 views

PfSense box not passing traffic between WAN and LAN

I just tried to insert a PfSense box into my network and I seem to have broken something in the process. Need some outside help to point out any errors I might have missed. The setup was working ...
0
votes
1answer
35 views

How do I create a subnet using the Google Compute Engine cloud console?

I am wanting to create a subnetwork as described here: https://cloud.google.com/compute/docs/reference/beta/subnetworks How can I do this using the cloud console? thanks
1
vote
2answers
6k views

Adding a network location via a command prompt?

I'm wondering if it's possible to add a Network Location via the command prompt? This is not a drive letter mapping mind which can be achieved using the net use command.
5
votes
1answer
2k views

Ping not working from tap interface attached to bridge interface with ip on same subnet as that of bridge to outside

My requirement is to create a multiple tap interfaces, each with ip address on same subnet. I tried this by creating a bridge br0 (192.168.1.199) ___________|...
3
votes
1answer
2k views

Limit/Throttle per user OpenVPN bandwidth using TC

I have a group of users connecting to my server via OpenVPN TCP and UDP (2 services). The two services are operating on tun0 and tun1 I'd like to be able to limit each user's bandwidth to say 5mb/s ...
1
vote
2answers
3k views

Juniper SSG5 DHCP IP Pool is full. Unable to offer IP address to client

hope we have some Juniper guys around, I have configured a Juniper SSG5 as our main firewall/router the DHCP server set on interface bgroup1 to have a rang from 10.10.10.76 to 10.10.10.210 All ...
0
votes
0answers
59 views

Openvpn client frequently uses a different IPv6 address causes a unstable connection

I set up an OpenVPN server on IPV6 recently, it runs well, except for one thing: the client loses connection frequently for Inactivity timeout (--ping-restart). Here's the log infomation on the client....
0
votes
1answer
22 views

Why is outbound bandwidth on VPS much less than reversed inbound from same host?

I have a FreeBSD 10.1 VPS in Europe using the VirtIO Ethernet device that sees significantly smaller outbound bandwidth than inbound from the same distant hosts. This problem was originally noticed ...
19
votes
1answer
6k views

How can e-mail be delivered to a domain without an MX record?

Somebody has 2 e-mail addresses: bob@domainname.com.br and bob@domainname.com . The DNS records for these domains look like this: domainname.com.br $ dig any domainname.com.br ;; ANSWER SECTION: ...
0
votes
2answers
46 views

single internet connection VS double internet connection

We have a two story building office and we are going to upgrade our internet connection. Is it better to have two separate internet connection with 15mbps each for first floor and second floor or just ...
37
votes
8answers
201k views

How to check the physical status of an ethernet port in Linux?

I want to check if a specified ethX is physically up or down. How do I do that with the command line?
1
vote
1answer
159 views

EnableLinkedConnections isn't working on some Windows 10 machines

I have been using the "EnableLinkedConnections" registry setting below for years with no trouble. But lately with Windows 8.1 and Windows 10, sometimes it doesn't work. I need to run some programs ...
4
votes
1answer
3k views

Unable to make work both private and public ip network on openvz container in Proxmox

I'm using Proxmox 3, it is a fresh installation. For those who know, I'm using OVH Vrack 1.5 (along with a previous Vrack 1.0). My server has two interface eth0 and eth1, I succeeded to configure ...
1
vote
1answer
3k views

Bringing the xenbr0 interface up on XEN under Ubuntu 8.04

I installed XEN on Ubuntu 8.04 using this tutorial but after I reboot with the XEN kernel, I don't have xenbr0 device. I see that network-bridge script runs and it creates peth0 device, but not xenbr0....
-2
votes
1answer
406 views

Linux - Only first virtual interface can ping external gateway

I created 3 virtual interfaces with different mac addresses all linked to the same physical interface. I see that they successfully arp for the gw and they can ping (the request is coming in the ...
-1
votes
1answer
28 views

Sharing Folder In A Specific Group

Good morning, can someone help me on my problem? Windows Server 2008, and 16 PC, in windows server I g create a 4 group, and I add specific users into a group,. I shared a folder in windows server, ...
1
vote
0answers
42 views

Iptables firewall causing instability

I've made a script to set an iptables firewall,but it's Causing instability on the local network aplication . The firewall is droping the connection between the clients and the server for a while ...
0
votes
3answers
49 views

Why another PC on lan can ping me even when I use /30 subnet?

Here is the set up: PC A : IP address : 192.168.1.2 Netmask : 255.255.255.252 Gateway: 192.168.1.1 PC B : IP address : 192.168.1.220 Netmask : 255.255.255.0 Gateway: 192.168.1.1 PC B is able to ...
1
vote
1answer
1k views

netstat -e: high discards and errors

I think my network is congested because of the relatively large discards and errors data. They should be zero or at least close to that. Here is the output of netstat -e on my computer: Interface ...
0
votes
1answer
74 views

Block DHCP server from other network

I have problem on PC's (Windows 7) with two network interfaces, sometimes nic that is supposed to be in network 10.1.19.0 has address from 192.168.0.0 My networks: 192.168.0.0/24 with DHCP running on ...
0
votes
0answers
16 views

No IPv6 connectivity from docker container

i'm having serious problems enabling IPv6 in docker. Environment The host is running Debian Jessie. It's a virtual Server (KVM). eth0 has a statically configured address like w:x:y:z::1 in a ...
0
votes
0answers
59 views

create a PPTP VPN server to act same as PureVPN PPTP server?

I'm new in networking. Our ISPs are providing us with private IP addresses so port forwarding is not possible, They are offering fixed IP addresses but with extremely high price so the only option is ...
1
vote
0answers
57 views

Failed to bring up eth0; can't establish any network connections

So for 1,5 years now I was running a DigitalOcean droplet without any problems. did apt-get upgrade several times, changed some things - all fine! Last night suddenly all my alarms went off and my ...
-1
votes
0answers
34 views

OpenVPN gateways configuration with non-routable addresses

I have to configure OpenVPN gateways with cryptographically protected tunnel connecting two non-routable subnet addresses. Mutual authentication gates on the basis of certificates. I used this ...
0
votes
1answer
183 views

Providing root ssh access to virtual servers behind NAT? [duplicate]

We are a web hosting company. We have 4 Servers which are running OpenVZ on top of CentOS. Each of the server has around 50 containers running on top of it. We are planning to provide ssh root ...
0
votes
1answer
29 views

Can i use the Azure DNS Service for my private network(s)?

I have the following situation: An extranet with multiple internal network zones, with private ip ranges (10.x.x.x (subnetted), 192.168.x.x.x etc..). These networks are connected using dedicated / ...
0
votes
0answers
23 views

irregular timeouts for new connections through vpn

We have some local servers and a VPN to our hosting partner where our production servers reside. From time to time (no "schedule" recognizable!) we can't connect to the production subnet: the vpn is ...
0
votes
1answer
16 views

Cannot access D-Link DES 3200-10 after resetting account

I've forgot my password and after googling I've found that in recovery mode I can reset my account. Connected to Switch using console port (VT100+ Keyboard compatible) and pressed Shift+6. I accessed ...
6
votes
1answer
74 views

How to make a disconnected drive?

kind of a weird question but how do I make a drive go from a OK state to disconnected state using net use? I do not want to delete it. I am testing a script but the annoying thing is that to test the ...
18
votes
2answers
1k views

What's the Wireshark packet receiving and processing procedure on a Windows machine?

I am about to use Wireshark for some traffic monitoring on my Windows computer. While working on it, I was wondering how Wireshark manages to catch low level network packets before Windows does. ...
0
votes
0answers
49 views

OpenVPN Server on Windows does not accept connections

I currently have a strange problem with my OpenVPN Server. I am using OpenVPN 2.3.11 on a Windows Server 2012 R2 Standard. The problem is that after a while (between 5 and 10 hours) after the OpenVPN ...
19
votes
9answers
17k views

What is the OSI model and how does it apply to todays networks?

As a system administrator what should I know about the OSI model? (Rec X.200) Briefly, what are the layers and what do they do? How much do I need to know about in my day-to-day work? How does this ...
0
votes
0answers
40 views

How can I change the network adapter of a vm using a cli in esxi?

I want to change the network adapter of a guest virtual machine using esxcli, vcli or any other cli means. I couldn't find an esxcli command, which is expected as its scope is primarily the host. I ...
0
votes
0answers
14 views

OpenWrt - connecting WLAN and LAN at network level 3

I have a Linksys WRT54GL router with OpenWrt installed. I would like to create two independent networks, each with its own DHCP server: one WLAN and one regular LAN using the switch ports. My /etc/...
1
vote
2answers
3k views

Unable to ping multicast IP

Let me prefix this by saying I'm not entirely clear on how multicast works. I have the gist of it, but not the underlying functionality. A customer has configured a RHEL6 cluster between two Jboss ...
0
votes
0answers
57 views

Ping inconsistent but works just to different address

When I ping a static external IP address on my internal network it works half the time directly to the IP address but then half the time it is going to the router address first. Is there some things I ...
0
votes
0answers
19 views

Need help configuring a second VLAN on a managed switch please

Got a network using a Sonicwall and HP 1920 managed switch configured as follows: Sonicwall: X0 Interface - 192.168.2.251 X1 Interface - WAN Connection X2 Interface - 150.9.1.251 (Different Zone) HP ...
0
votes
1answer
1k views

How can I block all traffic to/from an bridged interface while allowing DHCP?

I have a PC (running Fedora 20) that is being used as a "software switch" to control the network connectivity of some external devices. There are eight such devices; the PC has two 4-port Ethernet ...
1
vote
2answers
5k views

Printer on different network(IP range), can i print to it?

Heres my situation, client PC is on the same network as the printer to start with: 192.168.1.X Thats fine and printing is fine, however our clients are required to connect to the VPN using the ...
0
votes
1answer
74 views

OpenVPN Windows 10 Server, Windows 7 Client, can ping each other on VPN IPs but nothing more?

Server config: port 1194 proto udp dev tun dev-node MyTap server 10.8.0.0 255.255.255.0 ca "C:\\OpenVPN\\easy-rsa\\keys\\ca.crt" cert "C:\\OpenVPN\\easy-rsa\\keys\\server.crt" key "C:\\OpenVPN\\...
3
votes
2answers
4k views

UDP port appears to be in use but is not shown in netstat or TCPView

I've encountered some strange behavior I don't understand. I'm installing software on a Windows 2003 Server. This software needs to bind to a specific UDP port an all TCP addresses in order to listen ...
21
votes
3answers
24k views

How to use Bonjour?

First, what exactly Bonjour does (pleas read my guesses written bellow)? Here I found out that Bonjour enables automatic discovery of computers, devices, and services on IP networks. But I thought ...