Tagged Questions

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

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3
votes
1answer
96 views

How do I make a connection private on Windows Server 2012 R2

After a restart of one of our servers (a Windows Server 2012 R2), all private connections become public and vice versa (this user had the same problem). Stuff like pinging and iSCSI stopped working, ...
0
votes
2answers
166 views

(network unreachable) error in my server logs

I'm getting lots of network unreachable lines in my Centos' messages log file. They seem they can't resolve to certain addresses which I do not have any ideas why my server has to resolve to them in ...
2
votes
0answers
46 views

Non-local IP for next hop in routing

I'm working with an MPLS network and I am slightly confused about some route entries. Interfaces are (these are fake IPs): eth0 10.10.10.1/24 (LAN) eth1 10.9.9.1/24 (MPLS) eht2 2.2.2.2/24 ...
0
votes
1answer
30 views

Input traffic spikes on outside interface at same time every day

For the last two days I've had this issue where our internet connection SLOWS to a crawl and is almost unusable. I logged into our Cisco ASA 5500 (not very well versed with it) but I was able to see ...
0
votes
1answer
37 views

Cannot access Windows default shares using windows credentials

I am on (Windows 8 -ADMIN-PC) (192.168.1.10) with DNS. My other PC (windows 7 -USER-PC) (192.168.1.11) with same DNS In my PC (Windows 8 -ADMIN-PC) I try to access user-pc by using windows explorer ...
0
votes
1answer
19 views

Forwarding traffic from one virtual interface to another

I have a router with two ethernet interfaces: eth0: 1.1.1.2 (with 1.1.1.1 gateway) eth1: 2.2.2.1 I created two new virtual interfaces: eth0:1 : 1.1.1.3 (with 1.1.1.1 gateway) eth1:1 : 2.2.3.1 ...
1
vote
0answers
34 views

Redirect Default Gateway Traffic in Linux to File

I am trying to troubleshoot one of my linux servers (ubuntu server). Therefore I want to intercept all traffic that is sent to the default gateway and then write it to a file: preferably some kind of ...
-1
votes
1answer
46 views

3 NICs in VMware ESX 5.5.0 cannot connect to each other [closed]

I have a Vmware ESXi 5.5.0 hypervisor, installed on a desktop pc with 3 physical NICs. The first NIC is connected to the internet (WAN), the 2nd and 3rd NICs have Access Points installed (plugged in) ...
-1
votes
2answers
60 views

Why can my servers not access their own addresses? [duplicate]

I have two VMs on CentOS 6.5, running Plesk 12, and the webserver is Apache 2.2. One is a clone of the other, and I inherited them setup by someone else. My problem is that I can access my sites ...
0
votes
0answers
137 views

base filtering engine fails to start - error 5 access denied. Server 2008 R2

We had a major server fault over the weekend where some hard drives and the mainboard's raid controller failed. Mainboard and HDD's replaced - the Windows Server 2008 R2 is loading up, but many of the ...
0
votes
1answer
46 views

iptables not allowing ssh

This is my iptable configuration. But I cannot connect with ssh with these rules. What am I doing wrong? I want to block all traffic except ssh coming from x.x.x.x ip address. iptables -F iptables -X ...
3
votes
1answer
62 views

Cisco CVE-2014-0224 Vulnerability

We have a Cisco RV-042 Small Business router and our PCI scans flagged it as being vulnerable to CVE-2014-0224 (CCS Injection/Man-in-the-Middle). It appears to be another OpenSSL vulnerability. We ...
-4
votes
1answer
36 views

can same private IP will communicate? [closed]

Suppose Company A's Lan's network address is 192.168.10.0/24 and B's LAN network's address is 192.168.10./24. when company A brought company B..then as usual they also need to make communication ...
-2
votes
3answers
48 views

understanding resolv.conf nameserver through system calls [closed]

I am trying to understand how /etc/resolv.conf /etc/nsswitch.conf exactly works and what is significance of nameserver entry 127.0.1.1 I did strace ping google.com to get to know about the system ...
-1
votes
1answer
32 views

understanding resolve.conf nameserver through system calls [duplicate]

I am trying to understand how /etc/resolve.conf /etc/nsswitch.conf exactly works and what is significance of nameserver entry 127.0.1.1 I did strace ping google.com to get to know about the system ...
1
vote
2answers
85 views

Test port reachability from a remote host even though the port is not bound to a service?

I need to check whether a remote host is able to reach a specific port. At the time of test the service bound to that port will be down. The possible issues that the test would address would be : ...
0
votes
1answer
105 views

CentOS 7 (Dracut) - Network boot with gateway in different subnet

I'm trying to auto-setup VM guests with CentOS 7 using network boot and kickstart with external network connectivity based on linux bridge. And I'd like to have solution lightweight, simple and ...
0
votes
0answers
38 views

Why is the first of two post-up commands for routing in interfaces configuration not automatically processed

We managed to connect our servers to two distinct networks and everything works fine. We use routing rules that ensure that server responds to the right network. I followed the instructions under ...
-4
votes
2answers
50 views

How to force the network machines to get the ip from a DHCP server? [closed]

How can I force all the network machines to get the IP from the DHCP server and prevent them from manually editing the network configuration. There are both Linux and Windows machines. The DHCP server ...
-9
votes
2answers
48 views

is it possible to have Web server and NAS on the same hardware microsever? [closed]

I have a HP microserver proliant gen 8, and i want to know if there's a way to make this hardware work as NAS with freeNAS ... etc, and in the same time make it work as a web server with Centos Nginx ...
1
vote
0answers
27 views

Receive many UDP packets & ksoftirqd load

I want my server to be able to handle more than 1Mpps from a 10g card. Is it possible? I have Ubuntu 14.04 with kernel 3.11 and a 16 core Xeon machine. It seems that ksoftirqd becomes bottleneck in ...
2
votes
2answers
89 views

Can PoE kill unmanaged switches?

Two simple unmanaged switches have died in the same cabinet in two years, one at 18 months and one just today at six months. Both times we gradually experienced increasing intermittent verified ...
0
votes
2answers
60 views

Is there a way to find which IP I am connected to?

Let's say my eth0 interface has multiple IP addresses and I can connect with SSH to any of these. Is there a way to find out which of those I am connected to? (The background is that certain ...
0
votes
1answer
81 views

How to trace dropped TCP connections?

Trying to help someone with a situation where TCP connections get mysteriously dropped after a few minutes for no apparent reason (this happens even with non idle connections). Both client and server ...
-2
votes
1answer
47 views

How can I access a Virtual Machine on different subnet? [closed]

I have two virtual machine VMachineA and VMachineB using virtual box. VMachineA (CentOs 6.5) has two network interfaces: eth0 (IP: 192.168.3.48, GW: 192.168.3.1) and eth1 (IP: 10.10.200.1). ...
0
votes
1answer
36 views

tomcat-webapp not accessible via port after windows-update

we are running 4 Virtual Machines on a MS HyperV Host. On one of the VMs (192.168.50.15) we have multiple Tomcat-Webapps on separate ports - 9010: Jenkins - 9020: Atlassian Jira - 9030: Wiki .. ...
0
votes
1answer
67 views

Proxmox VE: Multiple shared public IPs with NAT configuration

I have a Proxmox VE (v3.3 @ Debian 7 Wheezy) and got 3 public IPs routed to that server. It is my aim to have multiple VMs sharing those IPs using a NAT configuration so that I can forward single ...
0
votes
1answer
511 views

BIND failing to resolve with 'WARNING: recursion requested but not available'

there are no errors in the logs and query logging won't initialize iptables is fully disabled but the server will respond with "WARNING: recursion requested but not available" because my client ...
0
votes
1answer
96 views

Routing from VLAN to Internet via L3 Switch

Please excuse the brain-dump - trying to solve a problem that's had be running around in circles for an entire day! TL;DR - Clients on two networks separated by a L3 switch can see and ping ...
4
votes
2answers
504 views

Will blocking port 25 on a router cripple outlook clients?

I work at a small ISP, we manage about 60 buildings with p2p radios and a main cisco router at a central location. Recently we were notified that a phishing domain is associated with one of our IPs. ...
1
vote
2answers
35 views

Software installation by group policy

I have a server with windows 2008 r2, it is connected N client. Clients use software that releases updates. Is there an application that I install on the server, which allows you to select the ...
0
votes
2answers
95 views

Forwarding HTTPs requests to another webserver

I have an Ubuntu 12.04 Server connected to two subnets. Eth0 is 20.20.20.1, it hosts an Apache Web Server on port 80. Eth1 is dynamic IP address in 10.10.10.0 subnet. This server is not a gateway ...
0
votes
1answer
89 views

Is this a botnet? [closed]

I manage networking equipment at a small ISP for 60 highrise buildings. Each building has anywhere from 1 to 60 24 port switches, or some DSLAMs, or some coax gateways, with p2p radios on the roof, ...
0
votes
0answers
182 views

iSCSI connection drops frequently - Synology NAS

I have a Windows 2012 R2 Server connected through iSCSI to my Synology Rackstation 2414+. The problem is that the connection drops very very frequently, up to 10 times a day (manually restored ...
1
vote
1answer
45 views

UDP Proxy with cloned packets

Having UDP messages sent from dynamic public IP periodically to public IP X:20000. Need a proxy that listens in IP X:20000, then forwards duplicate/clone packets to X:20001 and a different machine ...
-1
votes
1answer
50 views

Can't set up the default route from a sublan to the WAN [closed]

I am trying to connect one of my PCs to the Internet via a WiFi network using a notebook. Here is my network : (Wifi) <=============> (Notebook) <===============> (Desktop) ...
0
votes
2answers
137 views

Setting up a server with two NICs using two separate subnets (each on a different VLAN)

I'm using Ubuntu 14.04 (standard server install + OpenSSH, biosdevname=0 during instal to keep the network names simple) in an environment where I have two non-overlapping subnets M and N on different ...
0
votes
0answers
24 views

Static Route Dual LAN CARD Centos 6

First let me explain the scenario. I have two internet connection (Lease LINE and BroadBand). I have a CENTOS 6 Server which is used for VOIP calling (GOAUTODIAL). Now I want everyone in the LAN to ...
0
votes
0answers
42 views

Dell PowerEdge 1950 - Remote Access Controller not showing in router status

I just received a Dell PowerEdge 1950 server that was pulled during a company wide IT upgrade. I got the system with blank hard drives, installed ubuntu Server on it. I am able to connect the ethernet ...
0
votes
0answers
47 views

IPFire configuration as IDS behind router

I want to use an IPFire-Server primarily as an IDS behind an already existing router. The network's router (192.168.1.1) has access to the Internet and provides LAN-Slots for the clients. There is ...
-2
votes
1answer
52 views

How can I connect two machine's networks using a software approach?

Updates: let's assume the locations are separated, so WAN transversal is a must, and no physical networking is possible. I want to be able to connect two machine's networks together using a ...
0
votes
1answer
45 views

multi-wan problems with web services

I recently set up a multi-wan connection for a small company, because they are at the end of the line for any possible ISP, services do go down, and they really depend on their Internet connection. I ...
0
votes
1answer
56 views

How to assign different static IP addresses to the same machine depending on its OS on a network? [closed]

I was wondering if it is possible, e.g. to assign/reserve one static IP to a computer when it's running windows and assign a second static IP to the same computer/MAC address when it's running Linux? ...
1
vote
0answers
64 views

Load Balancing over multiple ISP connections

I have been trying to implement load balance and fail over on a linux machine having multiple interfaces. Currently I am using two ISP lines and I wish to split the network traffic such that both of ...
1
vote
0answers
28 views

Using a G. 655 with a G. 652.D fiber cable?

Is it possible to use a G.652.D patch cord with a G.655 fiber cable for just a small distance (less than 10 m) for the interconnect only (from the patch panel to the switch) ? If yes or no, what will ...
-2
votes
1answer
22 views

Setting up a FreeBSD Server for packet filtering and routing [closed]

I have heard the many goods of using FreeBSD in Networking over Linux with utils such as pf and ipfw I currently have an multi tier application hosted on a vSphere environment with seperate servers ...
20
votes
2answers
2k views

Why is my eth0 called eno16777736?

I've seen http://www.freedesktop.org/wiki/Software/systemd/PredictableNetworkInterfaceNames/, which describes the rationale for consistent/predictable device naming, and then the rules by which device ...
0
votes
0answers
25 views

OpenVPN - manually config IPs allocation

Yesterday I did this question about a strange fact (that firstly I thought it was some misunderstood from my part, but now looks real) that OpenVPN cannot allocate more than 63 clients when using ...
0
votes
1answer
57 views

How to configure a RedHat 6 server to always use the gateway?

In one of my datacenters, I need to configure the server to only speak to the gateway even if the other server is in the same network... How can I configure the network card ? I suppose something ...
0
votes
0answers
26 views

FreeBSD jail loses network connectivity after some time

I have a Jail on a FreeBSD 9.2 installation on my office network, which I use to run some cron jobs that upload and download stuff from external servers. The cron jobs are configured on the main ...