Ethernet is the most common set of standards for wired connections in local area networks.

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812 views

10GbE be2net low pktgen performance

I am testing the network performance of two workstations, each having 2.4GHz Xeon quad core processors and NC550SFP PCIe Dual Port 10GbE Server Adapters, linked back to back. I've checked the ...
0
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0answers
17 views

route vpn over wifi when ethernet is first priority

I have a very special problem and google couldn't help me so far. I usually connect to the Internet via ethernet (en3). For some applications etc I need a wifi connection (en1). So my service order ...
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2answers
236 views

How is a TCP request routed from a virtual machine to an outside resource and back again?

Scenario: Computer A has a local ip of 192.168.1.100, which is running a VM inside of it. The VM now makes a tcp request to an external IP address (74.125.225.98). Could someone explain how the ...
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2answers
119 views

Different speed on Internet connection by switching NICs. Can someone make sense of this?

I solved my Internet speed problem, but I'm still puzzled. I can't understand what happened. My scenario: a small intranet is connected to Internet through a Linux gateway that connects to a Cable ...
3
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2answers
80 views

Is a DCB switch required for a FCoE setup?

I'm looking to play around with a test Fibre Channel over Ethernet (FCoE) deployment between 2 Xen servers and 1 storage server. Eventually I plan to replace our ageing NFS shared storage solution. ...
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2answers
1k views

Ubuntu Server, 2 Ethernet Devices, Same Gateway - Want to force internet traffic through 1 device (or at least allow it to work!)

I have a Ubuntu 10.04 Server with 2 ethernet devices, eth0 and eth1. eth0 has a static IP of 192.168.1.210 eth1 has a static IP if 192.168.1.211 The DHCP server (which also serves as the internet ...
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0answers
24 views

Difficulty sharing physical ethernet device with Xen 4.4

I have a virtualized PowerEdge T320, with a Ubuntu Server 14.04 running Xen 4.4 as host, that I use at my lab to do scientific computations (I'm the admin of the machine). This server has two physical ...
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1answer
72 views

What is the difference between an Up MEP and a Down MEP for Ethernet OAM CFM?

I'm having trouble understanding the functional difference between an Up MEP and a Down MEP in CFM applications. Some sites say they are defined based on network direction, others seem to think they ...
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0answers
12 views

issue with QSFP+ to 4x SFP+ cable

I have a Gigabyte MD60-SC0 motherboard which has a QSFP+ port. I need to connect this with another machine I have which has a Intel X520-SR2 NIC (with two SFP+ ports) plugged in. I also have QSFP+ to ...
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27 views

Debian ethernet interface goes down while streaming video

While streaming video FROM a debian box to the rest of a network, I regularly see the ethernet interface go down on this box after a couple hours of streaming and it doesn't come back up until the box ...
3
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1answer
32 views

Unable to access network on Windows Server 2012 (Ethernet)

We have a server that had been using Ethernet, but temporarily Wi-Fi, and is now using Ethernet again. Strangely, it will not connect to the Internet. It detects when a cable is plugged into the port ...
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2answers
54 views

TCP/UDP Small Package Size optimization [closed]

I currently have the problem, that when a LOT of RTP streams (>800) go to one server the max. speed is onlynabout 70-80 Mbit (on a Gigabit LAN - all Hardware components are Gigabit components) 130 ...
2
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3answers
161 views

Why is cat6 required for long cable runs?

I'm glancing over a Ubuiquiti airFiber radio starter guide and it says "outdoor shielded 5e or above cabling should be used for all wired Ethernet connections. Category 6 is required for ...
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0answers
27 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: ...
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1answer
88 views

How do I increase the ring parameters for a NIC on a Linux server

I used the ethtool utility to increase the rx and tx values for the NIC on one of our servers. I ran the following command: ethtool -g eth0 Ring parameters for eth0: Pre-set maximums: RX: ...
3
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1answer
74 views

Any benefit and/or risk in enabling Jumbo Frames for the DAG replication network?

Exchange 2013 DAG, two nodes, a dedicated GBE network interface on each server for replication traffic, connected to a GBE switch, using a dedicated VLAN. Is there any benefit to Exchange replication ...
0
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1answer
19 views

How to fix non-working ethernet under Linux, with RX permanently increasing?

I have a system with the latest Linux Mint. An ethernet cable which yields internet with no special action from me under Windows 8.1 is detected under Linux, but does not seem to work. Running ...
2
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2answers
191 views

What percentage of its capacity should I aim to run a network at?

First of all, apologies if this is the wrong StackExchange site for this question - it's about Ethernet network capacities, but not specifically about servers etc. I am designing a network for a data ...
0
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1answer
121 views

Routing traffic externally instead of internal loop

I have one Ubuntu box with 2 network cards. I am running netperf on the computer to measure performance of networking equipment, ethernet coming out of eth0 into the switch then back out into the ...
1
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1answer
63 views

Connect access switches to router or core switch

My workplace consists of 4 access unmanaged network switches from three different computer rooms connected to a router. The router contains three 100mbps ethernet ports and one Gigabit (GigE) port. ...
0
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1answer
50 views

Is it possible to tell whether I am connecting to fast or gigabit ethernet with CAT5e cable?

My NIC supports gigabit ethernet: $ ethtool eth0 Settings for eth0: Supported ports: [ MII ] Supported link modes: 10baseT/Half 10baseT/Full ...
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1answer
59 views

Does the IP -> Ethernet multicast address mapping ambiguity matter for IGMP snooping switches?

There are 2^28 possible IP multicast addresses, but only 2^23 possible Ethernet (MAC) multicast addresses (http://technet.microsoft.com/en-us/library/cc957928.aspx), which is why e.g. 224.1.1.1 gets ...
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2answers
1k views

What is the clock frequency inside 10Gb and 100Gb Ethernet cards?

As I understand, a 10Gb Ethernet card is capable of putting 10Gb every second on (say) a fibre optics cable. Now naively, for this to happen in hardware, one will need a 10GHz clock running the ...
0
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1answer
106 views

OpenVPN cannot connect to local machine that has two NIC cards

This is my first time EVER posting to these forums. Most of the time when I have an issue I can usually solve them by searching forums/Google. But this one issue has me stumped! My company just ...
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6answers
6k views

Effect of heat on CAT5 Ethernet Cabling

I am wondering what the heat rating is on standard CAT5 cabling or where I can check the heat rating of my cabling by using the information inscribed on the cabling? In my specific situation, I am ...
2
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1answer
304 views

Full MTU not utilized with jumbo frames enabled

I've been testing to see if I can get any benefit from enabling jumbo frames. I've set up two identical Dell R210 servers with Xeon quad core E3122 CPUs, 8G of RAM and Broadcom NetXtreme II BCM5716 ...
3
votes
3answers
481 views

Is an Ethernet point to point connection without a switch real time capable?

In automation and control, it is commonly stated that ethernet can't be used as a bus because it is not real time capable due to packet collisions. If important control packets collide, they often ...
2
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1answer
239 views

Is there a standard managed switch configuration protocol?

is there a vendor-independend managed switch configuration protocol e.g. for creating VLANs that can be run over TCP or serial port?
2
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1answer
59 views

Two LAN cables when using Remote Access Card?

I recently bought a HP MicroServer N54L and a HP Remote Access Card. Connecting to the server over a KVM viewer for BIOS setup etc. works fine, but when it comes to installing Ubuntu 14.04. the ...
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0answers
103 views

Can't seem to see local network on Wine

I'm trying to use Wine on Ubuntu to use a proprietary Windows program that looks for a proprietary device on the local network. I don't know where it's looking, which protocol, port or IP address it's ...
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1answer
78 views

What is the most proper way of wiring RJ45 for Cat6/LAN?

I currently know of three different wiring patterns for RJ45: T568A, T568B, and USOC. Simply put: Which is the best method for creating a Cat6 cable? From my research, it seems like I should use ...
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1answer
104 views

ethernet switch makes network down [closed]

I have a D-Link 8-port Ethernet switch which was perfectly working. Since 2 days ago it makes the entire network down. The problem is when I disconnect the cables it runs again and after I connect ...
2
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1answer
1k views

e1000e Reset adapter unexpectedly / Detected Hardware Unit Hang

I have a Dell 1U Server with Intel(R) Xeon(R) CPU L5420 @ 2.50GHz, 8 cores running Ubuntu Server Kernel Version 3.13.0-32-generic on x86_64. It has dual 1000baseT networking cards. I have it set up to ...
5
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3answers
630 views

Gigabit uplink versus regular switch port

I have a 10/100/1000 24-port + 2 mini-GBIC ports switch which I have to link to other switches. Unfortunately, on the other switch all the mini-GBIC slots are taken up, so all I can do is link them ...
0
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1answer
716 views

dhcp-server + iptables: Can't share ppp internet connection

I had this configuration before, and it used to work well, but now I got a new server and I can't setup it to share the internet connection from ppp0. I'm on Debian testing. The client connects ...
0
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1answer
20 views

Why am I seeing prefixed/duplicated packets coming from a comcast device?

I'm looking at traffic my CPE from Comcast in Wireshark, and for every packet, there is an additional packet that is the exact same, except for 4 additional bytes at the beginning of the frame ...
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4answers
90 views

Same static IP addresses to single static IP address communication [closed]

I have a server with 4 modules, and one Ethernet Port and an internal hub to assign these modules to, configured as below. Module 1: 192.168.10.1 Module 2: 192.168.10.2 Module 3: 192.168.10.3 ...
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2answers
2k views

testing signals on an ethernet cable

I work on escalators that use ethernet cables to send signals from "nodes" to a PLC. the only tool available is a Fluke multimeter. is there a way of reading these signal using the meter? or do I need ...
2
votes
1answer
286 views

Automatically acquire IPV6 address in CentOS 6

The network has fixed IPv4 address, and automatic acquired IPv6 address. Does anyone have an idea how to setup? Thanks a lot! I didn't use NetworkManager. The following is my setting, but it does not ...
3
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2answers
336 views

What does 'Si' mean with respect to network switches?

I am seeing references to Multilayer Switches with Si as in the network symbol below. What does the 'with Si' qualifier mean?
0
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1answer
98 views

Suddenly unable to obain IP address but eth0 port blinking rapidly

After a server restart, the server is unable to obtain an IP address through a wired ethernet interface, neither automatically nor manually. However the green light on the back of the machine where ...
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0answers
108 views

zeroshell unsupported onboard Intel Ethernet I217-V and I210

I recently installed zeroshell 3.0.0 on a machine with a supermicro motherboard that has 2 onboard ethernet cards. It seems that this version of ZS does not support both of ethernet. I've read from ...
8
votes
3answers
2k views

What is, and what problems result in a 'carrier error'

I haven't found a really clear definition about what a 'carrier error' is within the context of the ifconfig output for a interface. I have been searching on Google and there really isn't a great ...
0
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1answer
50 views

Ethernet switch signal quality

Is there a (significant) signal quality difference between ethernet switches? n other words: A 1000base-t, do some switches allow longer cable runs than other switches?
3
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2answers
416 views

Should Carrier Ethernet traffic be encrypted?

I'm looking for a best practice answer. We have a 100Mb point to point Carrier Ethernet circuit between a corporate office and an offsite data center. Basically we have SQL traffic replicating to ...
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2answers
162 views

How can I change metric of public network in route table

In my windows 8.1 ENT [64 bit] machine I have 3 network adapters. Ethernet 1 is connected to public network and other 2 ethernet adaptors are connected to different internal networks. The problem is ...
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43 views

AR8151 eth0 heavy trouble

First I had really bad issue with network speed. There I got this good article: http://mindmapapp.blogspot.com/2012/01/use-atheros-ar8151-ethernet-card-on.html But now I have really crazy things ...
6
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1answer
459 views

Is it possible to detect rx+ rx- tx+ tx- wires with multimeter?

Is it possible to detect rx+ rx- tx+ tx- wires of an ethernet cable having only a part of cable with multimeter or somehow else? I mean the situation when you have just one side of the ethernet ...
0
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1answer
21 views

Use local Internet connection

I have a network split into through two ethernet segments through a virtual VPN hub. In the figure, blue is the part of the network that I control. My problem is due to the orange subnetwork, that ...
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vote
1answer
128 views

Network latency caused by incorrect cable?

Our team recently setup a new network and now we are experiencing network latency issues. the flow of traffic is as such: modem -> router -> packet shaper -> cisco3750 switch from router to packet ...