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

learn more… | top users | synonyms (1)

2
votes
0answers
3k views

Why can't I connect on port 445?

I need to collect baseline performance data on a SQL Server running on Windows Server 2008 R2. When I open perfmon on my computer running Windows 7 and try to add counters from the remote server, I ...
2
votes
0answers
1k views

Testing radius server from Mac OS X client

I have a radius server set up on a server running Ubuntu 11.04. I have configured my switch to use the authentication server's IP (192.168.1.2) for RADIUS / 802.1x authentication, and I created a ...
2
votes
0answers
1k views

IP Conflicts from mikrotik router for multiple ip addresses (that it isnt assigned)

I have a point to point wireless connection using two mikrotiks. When I plug the mikrotik into a switch with just my laptop I get an IP address conflict on my machine no matter what IP I am assigned. ...
2
votes
0answers
551 views

Getting ipsec-tools to work between Ubuntu Lucid hosts

I have two hosts, one is Charity with IP 67.207.128.184, the other is Hope with IP 67.207.130.204. I've installed the ipsec-tools package on each host. I have not installed racoon on either host. ...
2
votes
0answers
411 views

Xen and dhcp. Not connecting

I'm sorry if this sounds like a really stupid question but I started today for the first time using Xen. I'm using it on a fresh installation of Debian Lenny. I followed this tutorial ...
2
votes
0answers
109 views

How to configure MODBUS on a Cyclades TS100?

I have a Cyclades TS100 which is used to communicate with a Modbus Slave. I selected Protocol: Modbus and configured MODBUS Serial Mode: RTU The thing is, I event don't get a connection to the Serial ...
1
vote
0answers
52 views

Why does my server gets requests for domains that are not mapped to my IP

As title states ... Why does my server (nginx) gets requests for domains that are not mapped to my IP? I've split my nginx logs to create a log file for each website that it processes and i've ...
1
vote
0answers
16 views

VM LAB - Promiscuous mode clarification

So for clarification I am running a Lab within VMware behind OpenVPN, 1 NIC with direct internet access (WAN vswitch) and another NIC with a leg inside a LAN vswitch. (This obviously houses my VM's ...
1
vote
0answers
29 views

Xen VM could not be installed

I have rented a server from Hetzner. I have installed Xen on Dom 0 - Centos 6.5. I couldn't create a Dom1 Centos 6.5 VM. The Error I see is 'Unable to retrieve 'the link for centos image' while ...
1
vote
0answers
19 views

Dell PE2900 seeing only 1/2 ethernet controller

I have 2 ethernet controller on my dell poweredge 2900 : http://www.dell.com/downloads/emea/products/pedge/en/pe2900_Spec_Sheet_Quad.pdf But I only see one on my linux system : $ ip addr 1: lo: ...
1
vote
0answers
70 views

How to create a link between GNS3 and a VMWare Workstation VM that is totally isolated from the physical host?

My physical host machine runs windows server 2012 R2 with a DHCP server. I have the following topology in GNS3: Windows Server is the physical machine, it is connected to both VMNet 2 and VMNet 3 ...
1
vote
0answers
66 views

Hyper-V VMs keep losing network connection

We had a major power loss in our server room two days ago and several Cisco Nexus 2232PP FEX devices went down. We were able to get everything back online, but since that event we've been experiencing ...
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
vote
0answers
28 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 ...
1
vote
0answers
68 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 ...
1
vote
0answers
54 views

two different ping results to the same machine, what does this mean?

I am trying to track down a network or possibly server issue, and I opened a ping to the server from my machine. I will generally receive a <1ms response for a period of time, say 10+ minutes. ...
1
vote
0answers
65 views

How to access the setup wizard on Sonicwall TZ 100 firewall

I am trying to setup a TZ 100 firewall. I am following these instructions and I have attempted to follow these instructions: "Connect your computer to the LAN (X0) port on the SonicWALL. Connect an ...
1
vote
0answers
51 views

TCP Window Size Allocation, TCP Window Zero Errors and Network Latency

My mind is about to explode as everyone is always blaming the network guys for disconnections and slowness in the networks, but Solarwinds Reports that all utilization in the network devices and links ...
1
vote
0answers
72 views

Using my IPs on OVH server via GRE

I can't route my IPs into a OVH server, can you help me to find the problem? Mikrotik GRE IP: 192.168.55.10 OVH Server GRE IP: 192.168.55.20 GRE iface name: ali1_fr1-ovz1 IP to route from Mikrotik to ...
1
vote
0answers
418 views

TPROXY Not working with HAProxy, Ubuntu 14.04

I'm trying to use HAProxy as a fully transparent proxy using TPROXY in Ubuntu 14.04. HAProxy will be setup on the first server with eth0 111.111.250.250 and eth1 10.111.128.134. The single balanced ...
1
vote
0answers
43 views

Measuring latency with switch and identifying flow path

I have two machines, A and B, connected via switch S1(master) and s2(slave). I want to measure latency and identify packet flow path from machine A to Switch,switch to machine B. If the link between ...
1
vote
0answers
809 views

Ubuntu 14.04 KVM Host - Only network device pcnet working

I've installed a KVM host on Ubuntu 14.04. I've added a networking bridge as br0 and also added the p4p1 network adapter to it. My problem is now that only the "pcnet" networking guest driver is ...
1
vote
0answers
139 views

Command to set dscp / ToS value on outgoing packets for OS X Mavericks?

I want to set a certain DSCP (or ToS) value on all packets sent over port 22. I have an iptables command to do so, but Mavericks only has the equivalent of pfctl and I can't figure out how to ...
1
vote
0answers
139 views

Network Performance / SMB-CIFS / Guidance

I'm an IT professional working out of my home office. I'm having some performance problems (NAS file copies) which I'm trying to isolate, using iperf. My question is on iperf. Infrastructure - ...
1
vote
0answers
24 views

Windows DHCP MAC-Range to Scope allocation

I wonder if there is any options to map a specific Range of MAC addresses to a specific DHCP address scope. The thing is, I want a specific scope for address allocation to bridged Virtual Machines ...
1
vote
0answers
63 views

trying to reach a port forwarded server from the subnet using the public IP not working

I set up a server which is connected to my router. The router forwards a port of my server. So when I scan that port using http://www.t1shopper.com/tools/port-scan/ I got: 188.143.126.14 is ...
1
vote
0answers
64 views

Binding ISC DHCPD to a virtual (heartbeat) interface

I had a DHCP server that acted as a relay endpoint and worked fine. let's say this is a solo machine with eth0 with an ip of 192.168.0.10 I needed to bring this server down and join it to a cluster, ...
1
vote
0answers
36 views

Adding old T1s to a new configuration

As embarrassing as it is, my facility is running on two T1 lines. One connects us to AT&T and the other connects us directly to our corporate facility. This is a mirror of an old system we once ...
1
vote
0answers
74 views

HP ConnectX cards identifying as ConnectX EN

I bought a lot of four HP branded ConnectX card on Ebay. The cards are : HP InfiniBand 4X DDR ConnectX PCI-E Gen2 Dual-Port HCA 483514-B2 My problem is that two out of four cards identify themselves ...
1
vote
0answers
1k views

upstream timed out (110: Connection timed out) while connecting to upstream

I have my backend in France and one of my frontend servers is in Japan. This issue doesn't happen with any other of my frontends, only this Japan server, which already has about 2s latency from most ...
1
vote
0answers
79 views

Redundant Debian Gateway

I have to configure a redundant gateway with Debian boxes and I would like to get some recommendation what's the best solution in my case. There are certain limitations in my setup and I have to go ...
1
vote
0answers
53 views

How to view network resources used by a thread in Linux

I am trying to check the network resources used by a thread but unable to figure out how. lsof only allows us to give the pid. I checked under /proc/pid/task/thread/ but could not find anything ...
1
vote
0answers
170 views

Network share folder not accessible on one machine

I have a network file share folder available from one server on the network (running Zentyal 3.4/Ubuntu 13.10). I can access that shared folder from all of the computers on the network, except for ...
1
vote
0answers
47 views

Cisco RV016 dual WAN and VPN setup

I have a VPN of several RV016 routers and I want to set some of them with 2 ISPs. I plug the two ISP cables in WAN 1 and 2 ports and configure the router to "Intelligent Balancer(Auto Mode)". It works ...
1
vote
0answers
76 views

WSUS is not using Akamai CDN for syncronisation source

I've just installed a WSUS onto our network, and I'm currently doing the initial sync. I've found that WSUS does not seem to be talking to an Akamai cache, but rather with MS directly. This is ...
1
vote
0answers
69 views

cannot reach munin port on other AWS instance

2 AWS instances, in the same region but different availability zones, one is in regular EC2 and the other is in VPC, both have an Elastic IP, both are 64bit Amazon Linux AMI 2014.03.1. Both are ...
1
vote
0answers
62 views

All nework interfaces hang for seconds while one interface goes up/down

I am building a client/server application that uses several network interfaces in parallel for redundancy, and I have noticed that while one network interface goes down or goes up, the communication ...
1
vote
0answers
157 views

Make other VMs show in Network on windows server in Azure

I'm deploying a desktop app that connects to a remote database. standard 2-tier setup, but it's not a web app. People will log in via RemoteApp. But I'm having trouble getting the app instances in ...
1
vote
0answers
25 views

Losing connection to server from several computers

I have a PostgreSQL server running Oracle Linux. In my network I have several workstations each running different OS (Fedora, Ubuntu, Windows). Every once in a while I lose connection from the several ...
1
vote
0answers
265 views

Improving TCP performance over a gigabit network lots of connections and high traffic for storage and streaming services

I have two servers, Both servers hardware Specification are Processor : Dual Processor RAM : over 128 G.B Hard disk : SSD Hard disk Outging Traffic bandwidth : 3 Gbps network cards speed : 10 Gbps ...
1
vote
0answers
110 views

Windows mounted network drives slow after upgrading switch

On our small business network our old 10/100 consumer grade switch gave up the ghost, and we replaced it with a proper business-grade gigabyte switch. After wiring it in our Linux and Mac users ...
1
vote
0answers
243 views

How to setup two ssids on an asus rt-ac66u: one bridged to lan (no dhcp/nat), other dhcp/nat via wan

I was wondering if it's possible with asus rt-ac66u wireless router to create a configuration where the router provides two SSIDs as follows: The first ("intranet") should be bridged (with no DHCP or ...
1
vote
0answers
15 views

Connection problema to specific IP

Sometimes, like twice a year a have problems of connectivity from my server to an api server. And only to that api server. Other third party services we use were working fine. I am not so good on the ...
1
vote
0answers
63 views

Network flooded with LLC packet

Recently my network has been slow. From Tcpdump i found lot of frame with protocol LLC. A complete packet capture can been here tcpdump result Any hints on interpreting these packet?
1
vote
0answers
64 views

IBM BladeCenter H networking

I'm new to the IBM BladeCenter H, and I'm trying to figure out the networking side of it. I've installed a windows server OS on one of the blades, and am trying to fiddle with it's network setup ...
1
vote
0answers
49 views

Poor large transfers behind NAT on Centos

I have the following set up. A Centos 6.5 VM running on an ESX host, with a public IP4 address. It is acting as a gateway for (a bunch of) other Centos 6.5 VMs that are only connected to a virtual ...
1
vote
0answers
97 views

Make LXC containers available from the physical network

I've been trying to achieve the following. I want to use LXC as a thin isolation layer inside our physical machines, meaning each machine will have only one container running. For this container, I ...
1
vote
0answers
101 views

Firewall and NAT settings in GSM modem for one server

I have a GSM Modem (PSI-MODEM-GSM/ETH) in field with one device behind, acting as a server. The situation is as follows: "PC" | \_________Dynamic IP: 10.103.153.122 | ...
1
vote
0answers
478 views

XenServer IP Failover OVH not working

I have got problem on XenServer with IP FailOver in OVH. I did everything what is in this official tutorial http://help.ovh.co.uk/BridgeClient and IP not working. On my VM is Debian 7 64bit I set MAC ...