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

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Direct ethernet link between two servers

Say I had two servers which needed super-low latency (Database, file etc.). Would it be possible to directly connect the two servers with 10GbE, so each server had 1 (in the real world it would have ...
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2answers
431 views

Two network adapters with the same ip

I have two network adapters that use the same ip range, but are different networks. I tried this but it didn't work: iptables -t nat -A OUTPUT -p all -d 1.2.3.0/8 -j DNAT --to-destination ...
10
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1answer
2k views

Ethernet interface errors

My Ubuntu servers ethernet interface that connectes to ISP's multiplexer shows errors. Here is the snapshot: RX packets:204564288 errors:3193970 dropped:0 overruns:0 frame:3138402 ...
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1answer
57 views

Two network Macs have slow internet

I work in a boutique advertising agency as a web developer. I have my own servers at home for my website. In our office, we have 8 Macs. Two of the iMacs are against one wall with an ethernet cable ...
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3answers
4k 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 ...
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3answers
663 views

Ethernet link negotiates a connection only in half duplex mode

I have a NIC which is capable of 100BaseT/Full. But it negotiates a connection only on 100baseT/Half mode. Here is the output of mii-tool: eth0: no autonegotiation, 100baseTx-HD, link ok The ...
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4answers
2k 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 ...
0
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1answer
108 views

Server can only make outbound connections

My server is running Ubuntu 10.04 and is connected by ethernet to a router/modem device. The problem is that it's basically ignoring incoming connections. So I can't SSH into it or access the ...
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0answers
2k views

Descriptions of Ethernet register/counter names?

Is there a manual/datasheet/some other resource that explains what do all these counters in ethtool -S <interface> mean? Some of them are self-explainatory, some aren't... I'm taking them from ...
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2answers
261 views

Intel Server Board: Ethernet MT connection vs PM connection

What's the difference between an MT ethernet connection and a PM ethernet connection? Intel server board has two ethernet ports that are named in that manner.
0
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2answers
540 views

Carrier ethernet vs Metro ethernet or any other alternative?

We have three remote offices (office A, B, and C), two (Office B and C) of them need to access the Linux file server and web application server in Office C. We also need to administer the network of ...
3
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1answer
437 views

Programatically extracting interface configuration from the system?

I would like to produce a list of all the interfaces available on a [Linux] system, and for each interface, produce a list of available IP addresses. I was hoping to do this in a more graceful ...
2
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1answer
581 views

Multi-NIC Linux machine's NICs are responding to each other's ARPs regardless of arp_filter setting

I have an old Linux machine running a 2.4.37 kernel. In the machine are two NIC cards both on the same network with different IPs. For some testing, we want each IP's traffic routed through that NIC, ...
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4answers
206 views

Linux - Is there a way to determine what mac addresses an interface has seen traffic from?

Yes, I know about ARP but that relies somewhat on IP layer connectivity in that the remote system must be configured with an IP on a recognized subnet. Is there any way to just dump off what mac ...
3
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4answers
105 views

Is there a device or piece of software that can act as a transparent Ethernet bridge and limit bandwidth on MAC by MAC basis?

So for example, it will only let a particular MAC address on side A use 100kbps in ether direction.
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1answer
8k views

How do I configure a USB ethernet adapter under CentOS 5.3?

I've got a server running CentOS 5.3 (Final; kernel version 2.6.18) which I need to add a 2nd NIC to, initially temporarily, but eventually permanently. I'm not familiar with installing drivers under ...
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3answers
2k views

interface id for ethernet card

My PC (CentOS)has one ethernet card 1, linked to the internal company network for internet surfing etc., and another ethernet card 2, linked with an embedded device for programming. Each time, when ...
0
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3answers
675 views

SBS 2003 loses Connection to specific clients if not running Ping -t

I have inherited a client running SBS 2003 R2 and a mix of WinXP and Win7 clients. All machines have the latest updates. I started getting complaints that 1 or more computers would 'drop off' the ...
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2answers
2k views

How can I troubleshoot APIPA (169.254.x.x) in physical network cabling?

all: We have just started using an existing Cat5e cable to run 100Base-T to a new office, but unfortunately, machines in the new office see link but receive an APIPA address (169.254.x.x). I brought ...
19
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3answers
1k views

Best way to get the MAC of eth0?

Is there a more efficient way to retrieve the MAC address of a NIC in Linux? This works: ip link show dev eth0 | awk ' /link\/ether/ { print $2 }' but can it be found via something like: cat ...
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3answers
800 views

Virtual Ethernet Adapter / Multiple MAC and IP address for one adapter

I need to emulate multiple (10+) Ethernet adapters (different MAC and IP, same subnet) through a single Ethernet adapter. I know you can assign multiple IP addresses to a single adapter, but haven't ...
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3answers
263 views

Can't set up FC HBA with DHCP

I've got IP over FC working, and have the HBA (QLogic QLA2340) connected to a router with a DHCP server on it. However, whenever I do a: ifconfig fcip0 dhcp start I get: ifconfig: fcip0 wait timed ...
0
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1answer
871 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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5answers
252 views

Break Network between two hosts without pulling Cable

I have two Linux hosts HOST1 and HOST2 connected by cross cable. How I can break the network between then without breaking the physical wire (I don't have access). If i do: HOST1# ifconfig eth0 ...
3
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1answer
95 views

Machine cannot communicate on local network any more

I have a machine that has a problem I've never seen and cannot understand. The machine is a Dell laptop with Windows 7 Ultimate. The user tried to do something fancy with this machine (bridging the ...
0
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1answer
41 views

Configuring ip, subnet and gateway on eth interface

I'm in terminal on RedHat 5 and I need to configure one of the two eth interface with different IP, GATEWAY and SUBNET. I know ifconfig and route add but I'm not sure what I have to do for ...
0
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1answer
224 views

How to identify device and its IP on network by MAC on Ubuntu 10.04+?

I have a NAS (LinkStation Mini). Its windows software identifies it correctly. I want to identify device and its IP and mount the same.
0
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6answers
466 views

My wireless is faster than my lan by a lot… why?

At my job the wireless is pulling download speeds of 11mbps and uploading at 2mbps. The lan however is averaging around 2-5mbps download and 1-2mbps upload. Our setup is pretty basic, a cable modem, ...
10
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2answers
2k views

Why both T568A and T568B standards?

I've always wondered why there are the two different wiring standards for Cat5 UTP cabling. The only technical difference between the two is the green and orange pair are swapped, which accomplishes ...
2
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3answers
3k views

Can a broadcast storm develop in a loop caused by a wifi connection?

If my laptop or other computer is tied to a wired network, and it automatically joins a wifi router attached to that same network, can the two connections to the network cause a loop that starts a ...
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votes
5answers
2k views

Keystone vs. Feed-Thru vs. Punchdown Patch Panels

We have a new office that needs some ethernet wiring done to a cabinet in a closet (no more than 48 cables). There seems to be so many options now. I'd traditionally terminate everything at a ...
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1answer
609 views

Hardware won't respond to each others ARP requests

I have two pieces of hardware (embedded devices) that I have setup to communicate via TCP over Ethernet in a client/server fashion. The topology of the network is as follows: ----- | S ||=|== Debug ...
0
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1answer
968 views

SIOCSIFFLAGS: Resource or Device Busy

Have a Dell PowerEdge 2350 with dual nics built into the motherboard. eth0 works fine. Setting up an IP under eth1 results in the error: "SIOCSIFFLAGS: Resource or Device Busy". I have two ...
0
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2answers
116 views

Network topology

I am writing a network application that has several machines that serve separate clients, but machine themselves need to communicate with each other frequently. Let's say multiple chat servers for ...
0
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2answers
853 views

What does scalability mean when talking about ethernet networks [closed]

I need to do a homework and write a bit about ethernet. I am totally new to the topic, so i thought maybe some one could give me a hand by explaining me a bit about what scalability is, when talking ...
1
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1answer
170 views

Which cloud services allow layer 2 link level connections between servers?

There are advantages when you can deploy one server A so that it serves as the IP gateway for machines B, C, and D. In a real machine room, for example, A can balance incoming customer connections by ...
3
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3answers
566 views

Original Corinex powerline ethernet wall mount

I am re-purposing some old Corinex powerline ethernet wall mounts. They came with a setup cd with a wizard application for setting up the hardware, but the application doesn't seem to work on 64bit ...
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2answers
660 views

Using eth0 and ppp interfaces in a interchangeable mode

I've a Debian system without UI, with a GPRS modem attached to it. Now, this system is connected with ethernet through a standard cable. I want to obtain a configuration that allows the computer to ...
2
votes
3answers
594 views

Performance penalty of multiple IP's per network interface

How can I measure the performance penalty of a network adapter that is configured with 2 IP addresses per eth0 ? The network card has 2 physical interfaces (ports): eth0 and eth1 with only eth0 ...
3
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1answer
187 views

Port Mirror and 802.1Q

Does a port mirror send ethernet frames out of the switch-port with the 802.1Q header bytes still on the frame?
2
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1answer
348 views

STM-64 to Ethernet conversion: proper solution required

We need to arrange Ethernet network between two cities - this gonna be a partnership with other organization: we help them with equipment and get some bandwidth. I am newbie beyond 1 Gbit networks, ...
0
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3answers
126 views

HOWTO: Ring Ethernet Lan, My drawing Correct?

I have a special demand that to improve the redundancy of a network. (any of the cable between switches broken will NOT disconnect any clients) S = a switch C = a computer - = CAT5 cable ...
4
votes
1answer
501 views

Solaris ethernet ports: nge2 and nge3 are missing

There is a Sun X4100 with an interface nge0 which is configured and working. The server has a group of 4 network jacks in the back and nge0 corresponds to ethernet port 0. I tried enabling ethernet ...
2
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1answer
471 views

Acceptable number of ethernet errors in a medium sized environment?

I'm implementing a monitoring system for an existing modest sized data center deployment. So far I've only gotten to the host / application side of the monitoring equation but I'm noticing what I ...
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2answers
1k views

How can you force a Mac Pro's “Ethernet 2” link to UP, without a cable attached?

All Mac Pros / XServes have 2 gigabit wired NICs. It has always annoyed me that a: there is no way to bridge them (no BRCTL, et al. for Mac), and b: there is no way to "use" the second port, even ...
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1answer
2k views

What is theoretical maximum of TCP traffic over GigaEthernet?

What is theoretical maximum of TCP traffic over GigaEthernet ?
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1answer
244 views

System MTU for SAN switch

I have a SAN with redundant cisco 2960s when I set it up a while ago I set all of the interfaces to use an MTU of 9000. I was looking at the config today and I noticed this line system mtu routing ...
2
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2answers
840 views

Optimal Ethernet speed for dedicated web server 100Mbps vs. 1000Mbps

I'm busy upgrading my dedicated web server. The server only serves web users over the internet. It seems to me that any NIC speed over 100Mbps may be overkill considering all traffic is coming from ...
0
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1answer
90 views

Would using a bridged connection on a machine allow the machines connected to it use the internet?

In this specific case I wish to connect my first computer wirelessly to a router, and have the laptop use a bridged connection to Ethernet to extend to other computers. The other two computers will ...
0
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2answers
2k views

Linux is not sending arp request

We have a local network that is connected to internet through linux gateway. There are about 50 workstations in LAN. We recently started observing a problem that gateway sporadically stops responding ...