Ethernet is the most common set of standards for wired connections in local area networks.
6
votes
6answers
2k views
Expected throughput in Gigabit network
I've been doing some tests with iperf to measure the network throughput between 2 servers (connected back-to-back thru a crossover cable) and I only see 180 to 200 Mbps. I tried different cables and ...
6
votes
4answers
243 views
What's better for performance: rack-to-endpoint or rack-to-switch-to-endpoint
When putting Ethernet cables for an office there are two ways to put the cables:
From the rack patch panel a cable to each end-point (workstation).
From the rack patch panel a cable to each ...
2
votes
1answer
4k views
How does Brocade (Foundry) FastIron CX compare to Cisco 3750 stackable switches?
We're considering Brocade's CX series vs. Cisco's 3750 at both core and distribution layers for a new site with gig to desktop, without POE.
If you have any hands-on experience with FastIron CX ...
68
votes
17answers
19k views
Should network hardware be set to “autonegotiate” speeds or fixed speeds?
We recently had a little problem with networking where multiple servers would intermittently lose network connectivity in a fairly painful-to-resolve way (required hard reboot). This has been going on ...
4
votes
3answers
265 views
What if a computer with Ethernet
I'm just revising for an exam on Networks and Data Communications, and there's one thing I don't get about CSMA/CD and Ethernet. It's supposed to be fairly stable, for instance if a computer drops out ...
2
votes
2answers
563 views
Alternative options for ethernet over 75 ohm coax?
I'm in need of running ethernet between nodes in an older brick, steel & mortar building where 802.11* at any power just simply stinks, and no we can't run CAT5 through the walls. Primarily this ...
0
votes
3answers
75 views
Networked Remotely-Managed Media Player
We're looking to replace our current in-store video distribution model, which involves the production of a DVD ISO and several people burning discs and shipping them out.
Cost-benefit analysis shows ...
2
votes
5answers
384 views
Does it make sense to use 10Gbit Ethernet in a small business?
Currently, our small business is using 1Gbit Ethernet. We are a very data intensive shop and are currently running into bandwidth limitations between our individual machines and our RAID-based ...
0
votes
1answer
101 views
Restore eth2 interface?
i have centos 5, i have used "ifconfig eth2 down" and the server gets unaccesible, i can access to the files only at the moment, so i cant use "ifconfig eth2 up" to restore it, wich files have i to ...
0
votes
2answers
350 views
Recommendation for Ethernet switches that allow arbitrary network topologies [closed]
We have the following requirements for three Ethernet switches that will be connected together:
Allow the switches to connect together to form dynamic, arbitrary topologies, i.e., support for the ...
2
votes
5answers
1k views
Link aggregation with DSL and Ethernet, and different ISP's?
We're a webdev company that has outgrown its ADSL bandwidth. It's currently 4/1 Mbit/s and due to distance we can't simply get faster DSL, whether ADSL or SDSL. Stacking multiple DSL connections is ...
1
vote
1answer
1k views
Virtual Network card on a real Windows 7 OS
How can I add a virtual ethernet card to connect to a different network through my physical ethernet card?
I need something like Vmware network adapter...but on a REAL OS...not virtual one..
Please ...
9
votes
4answers
3k views
How does Ethernet know how long a frame is?
Looking at the Ethernet entry on Wikipedia, I can't figure out how it's indicated how long the Ethernet frame is. The EtherType/Length header field apparently can indicate either a frame type or an ...
4
votes
4answers
12k views
Tool to physically test ethernet cable with two network cards? [closed]
We're building ethernet cable or a non-profit community computer lab. We test them with a cheapie cable tester, which I believes simple checks the electrical connection of each wire. We're having ...
0
votes
2answers
116 views
What switch spec would i need to support 50 SIP extensions
Were a call centre and thinking of moving our phone system to a voip based setup. It seems most advice advises keeping this network seperate from the standard LAN, what switch specification would be ...
0
votes
2answers
178 views
Ubuntu through Wireless and VM through Wired
I am trying to do something like this:
All networking connections
originating from Ubuntu should go
through my Wireless connection
All the connections originating from
within Windows (installed ...
0
votes
1answer
249 views
What's a typical turn-around / response-time for this query/reply scenario?
I'm doing a feasibility study on a proposed wireless/wired network topology for a coming project of ours. A rough description of its use is "like an industrial sensor system". It looks something like ...
1
vote
4answers
3k views
How Many Wires Are in an Ethernet Cord?
Bought a spool of wire for networking. Ran it a long distance and thought we could hook up the wires to a plug at the end (not sure how to describe this).
However the spool of cord/wire we bought is ...
0
votes
1answer
426 views
What could cause “eth1: transmit timed out” on Debian 5.0?
I recently set up NAT using iptables, and I'm also doing some QoS with tc. While under heavy load, my server's ethernet device seemed to crash, I checked /var/log/messages and saw this at the time of ...
0
votes
2answers
440 views
wireless ethernet adapter with EAP-PEAP?
We have a wireless network set up to support WPA or WPA2 with AES or TKIP encryption and EAP-PEAP authentication. Users are wanting to connect devices that don't have the ability to do EAP-PEAP but ...
1
vote
2answers
722 views
NIC interface names in /proc/interrupts
When I look at /proc/interrupts:
$ cat /proc/interrupts
CPU0 CPU1
(...)
12: 4 0 IO-APIC-edge i8042
14: 145 65310875 IO-APIC-edge ide0
50: ...
1
vote
4answers
2k views
GigE ethernet switch backplane bandwidth
While looking for a 16- or 24-port gigabit ethernet switch with at least 6 VLANs and port mirroring (packet duplication to a monitoring port), I came up with three candidates (there are more): Cisco ...
17
votes
10answers
7k views
What's the difference between a bridge and a switch?
I can't find any authoritative source that can concisely explain the difference between a bridge and a switch. As far as I can tell, most devices commonly referred to as "switches" fit the description ...
0
votes
1answer
423 views
Asus Am604g as ethernet router
I used Asus AM604-g as ADSL router.
Not long ago I've moved from ADSL to LAN. Is it possible to use this device as ethernet router (I connect to LAN using VPN). If yes, how I need to configure it?
...
1
vote
4answers
3k views
How does a host route IP packets if it gets two IP addresses?
To clarify my question...
I am wondering how does the Linux kernel route packets on a multi-home host?
With 'multi-home', I mean the host has multiple NICs to send packets, for example my Debian in ...
2
votes
2answers
467 views
Best method to get “transparent” redundancy for Ethernet?
My apologies if this is an obvious question, I'm a newbie as far as redundant networking goes, and I'm not sure what keywords to Google for. My application scenario is this:
The system consists of ...
0
votes
1answer
93 views
COTS T1 over Ethernet/IP solution?
I am looking into a low cost solution to run a T1 link over ethernet, I found this one:
http://www.rad-direct.com/Product-TDMoverIP-Gateway-IPMUX11.htm
$1500 for the link. Anoyne else have other ...
0
votes
2answers
92 views
Design for wire between server and access point and RF to endpoint device
We're about to design an inhouse industry network consisting basically of the following: 1 server connected via wire to up to 100 proprietary RF access points (basically embedded devices), which each ...
0
votes
3answers
184 views
Switch Fabric Optimization
How does an ethernet switch work on a port-by-port basis? Specifications are given for the speed of the switch "fabric", but is that universal bandwidth through a central processor or are there ...
0
votes
1answer
799 views
Configuring ethernet port failover in Windows 2008
I have a Dell R300 server with two ethernet ports, running Windows Server 2008. I'd like to use one IP address, and connect to two switches. I only need one port at a time, I don't need more speed. ...
0
votes
1answer
569 views
802.1x authentication over wireless not wired
We have a wireless network that authenticates via 802.1x free-radius server. We have told the wireless network to authenticate accordingly and it works. However when we have a wired network we have ...
2
votes
2answers
323 views
How to identify/use existing fiber installation?
When my parents had their house built about 10 years ago, the wiring guy told them that he should install some fiber in the walls, saying that it would be good for future use. So there is some kind of ...
1
vote
5answers
3k views
Find the network card mac address in Windows
How can I find the network card mac address in Windows (7)?
0
votes
3answers
3k views
Ubuntu Server - Two Interfaces Living Together (in perfect harmony)
Our server has three ethernet interfaces. I have one plugged into the cable modem (for static ip), and one plugged into the router (for access to the rest of the work network). I'm pretty sure that I ...
4
votes
2answers
823 views
Network cabling Tips
I'm looking for some useful information about how to design network cabling for a building.
I'm not so much interested in wiring standards such as 568A, but more interested in physically wiring the ...
2
votes
4answers
2k views
Fiber Optic Cable not working
Basically I am having a problem with a fiber optic cable connecting 2 switches not working, hired a professional to help fix it and in the end it is still not working.
I need someone to look over ...
5
votes
1answer
579 views
What does a magic packet look like?
What does a magic packet contain and what options does the protocol provide?
2
votes
6answers
1k views
Packets sent indiscriminantly out of switch
Switches are supposed to only send traffic to a system if it's intended for that system. Ours appears not to: if I run "tcpdump not host myhostname", I can see lots of packets that are clearly ...
0
votes
1answer
727 views
IPTables rule to filter on ethernet address
I've a script to automatically block internet access after 11pm (23:00) and restore it at 6am (06:00). The script adds and remove some drop rules in iptables.
Unfortunately the filtering rule refers ...
2
votes
6answers
276 views
information about ethernet cards
I have few question and I don't find right answers.
What's the maximum speed of an Ethernet cable (not a phone cable! the one that has 8 threads)
About the Gigabit Ethernet Network Card: Is it just ...
3
votes
4answers
1k views
Ethernet Device Name in OpenSolaris
In Linux, I usually refer Ethernet devices as ethN.
What is OpenSolaris standard naming for Ethernet devices?
2
votes
2answers
546 views
The PHY on eth0 keeps restarting. How can I keep it on?
This is probably a superuser.com question, but it isn't online yet.
The PHY on my NIC is blinking on and off ridiculously, and it should always be on. I googled it and found no answers, just ...
0
votes
3answers
1k views
How many hardware (PCI-MSI) interrupts can a PC have?
On my workstation I got only two PCI-MSI interrupts in /proc/interrupts:
0: 11726919 0 IO-APIC-edge timer
1: 3 0 IO-APIC-edge i8042
7: 0 0 ...
2
votes
2answers
425 views
Networked USB Flash Drive [closed]
Is there a product that can be plugged into a computer and appear as a USB flash drive, while in reality it is also say a Samba / FTP server? Along the lines of the Eye-Fi card (www.eye.fi), but ...
2
votes
4answers
611 views
Has anyone had luck running 802.1x over ethernet using the stock Windows or other free supplicant?
I just wanted to see if anyone else has had luck implementing 802.1x over ethernet. So here's my basic setup. Switch sends out 3 eapol messages spaced out 5 seconds apart. if there's no response the ...
4
votes
4answers
711 views
The same driver for multiple network cards — performance bottleneck?
I'm using driver e1000e for multiple Intel network cards (Intel EXPI9402PT, based on 82571EB chip). The problem is that when I'm trying to utilize maximum speed (1GB) on more than one interface, speed ...
6
votes
9answers
5k views
Why does 1GBit card have output limited to 80 MiB?
I'm trying to utilize maximal bandwidth provided by my 1GiB network card, but it's always limited to 80MiB (real megabytes). What can be the reason? Card description (lshw output):
description: ...
0
votes
1answer
1k views
Best Hardware for Endian Firewall Community Edition
What would be the best hardware solution with 3+ Ethernet ports to install Endian Firewall Community Edition on? I am currently using a Jetaway mini-ITX enclosure with a Jetaway board and am not happy ...
4
votes
10answers
572 views
Windows packet sniffer
What packet sniffer would you recommend using, especially in a 50+ workstation environment? I am a fan of Wireshark but it's got quite a bit of security history. Is there something better?
3
votes
3answers
2k views
Really poor performance with 10Gbit Ethernet on custom app
I recently had a couple of 10Gbit Ethernet cards installed on a few machines connected to a LAN of about 80 commodity nodes running a distributed file system (Lustre). The 10Gbit card achieves good ...
