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

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1answer
191 views

“short” when testing an ethernet cable which is not connected to anything

There is a (~80m) Cat5e cable that stopped working a few days ago. I tested it with two different cable testers, and with both of them the result was: "short". Usually I get this result if there is a ...
0
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187 views

eth and bridge take very long time to set state on (debian 7 + intel i210 gigabit network controller)

It takes almost 5 minutes for eth link to get into state UP after reboot in debian 7 x64. The problem is those drivers are not in standard kernel, I had to install them from source (igb-5.0.6.tar.gz ...
0
votes
1answer
113 views

Unable to set initcwnd on a Hetzner server

We just ordered a bunch of Hetzner EX40SSD servers with the minimal Debian install image that they provide and everything is just fine except that looking at tcpdumps for fine tuning the network from ...
11
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5answers
1k views

A “splitter” is plugged into a patch panel… how does this still work?

I found a patch panel that splits off ethernet into multiple hosts as shown below. Can anyone explain how this might work?
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2answers
179 views

Ethernet port not detected

I just added additional 1gb port to my existing 4gbs on my server. All 4 are placed on a NET CARD PCIE 1GB E1G44HTBLK 904223 INTEL and the additional one is connected to motherboard(S5520SC) ...
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votes
1answer
48 views

Ethernet interface drivers (e1000 and NE2000)

What's the difference between e1000 NIC driver and NE2000 NIC driver?? I have tried to find out the answer on google but not been able to completely understand the difference
0
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1answer
235 views

PS6000 showing packet errors but no errors appear on the switch

We have a loaned PS6000E SAN that we are using to relocate our iSCSI LUNs off our current PS4000E SAN to upgrade it from Seagate Moose drives under a proactive replacement plan by Dell. We've ...
2
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1answer
116 views

How does a NIC send a hardware interrupt? [closed]

Some context. A few weeks ago, a NIC was replaced on a box without much troubleshooting to find a clear resolution to the problem. A senior administrator got into a small tiff with an entry-level ...
1
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1answer
101 views

PPP or Ethernet for fiber-optic link?

Since I have been doing a lot of IP camera jobs lately, it was only a matter of time that something really long-distance, more than can be covered with cat5e/cat6 cable, would come up. My current ...
0
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1answer
26 views

Strange issue on netadapter lantronix matchport bgpro

I'm connected to a switch on a LAN, i've tested my matchport on others network and i've not accused this problem. On this istead i seen a lot of UP and DOWN of eht0 on startup. Someone know something ...
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0answers
37 views

ELMI Packet Capture Tool

Is anyone aware of any software that is capable of sniffing and displaying elements for the E-LMI (Ethernet Local Management Interface) protocol? Wireshark doesn't seem to... I could write my own ...
13
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2answers
321 views

Ethernet port plastic plug blocking port access on server

I have Dell Poweredge server with plastic blockers inside their ethernet ports. My problem is that I don't know how to take it out. You can see photo of the plug here: I tried to pull them out, or ...
2
votes
1answer
201 views

Is it ok to use cat5e patches/jacks on cat6a cable for 10Gb

I understand that "technically" you are supposed to use cat6 cable jacks as well as cat6 patch panels. In practice I've seen cat6a plugged into cat5e patch panels, although I've never seen cat5e ...
0
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3answers
207 views

patch panels… or directly to the switch?

does it make a difference in terms of signal quality if I connect the Ethernet cabling: from the wall-plugs to the patch-panel and from the patch-panel to the switch with a cord. as opposed to: ...
2
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1answer
196 views

How can I stress an Ethernet managed Switch?

for testing purposes I need to stress an 8-port managed ethernet switch. Essentially, I want to simulate a scenario in which two hosts on the switch are exchanging data and the other hosts connected ...
0
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1answer
73 views

Ethernet Frames and CSMA/CD [closed]

I'm learning about Ethernet and I'm wondering if with several stations within the same Ethernet collision domain like pictured below, is it possible that a frame sent by station A is fully received by ...
1
vote
1answer
110 views

Maximum throughput on switch with different link speeds

While doing some benchmarking on a network app I discovered strange behavior that involves 100MBit and 1GBit ethernet clients connected through a switch (at-gs900/8e). I have one server (Gbit) and ...
3
votes
1answer
121 views

TIA 568A vs. B Wiring for Long Ethernet Run

I have a long Ethernet run (about 280 ft/85 m) that goes through a conduit between two buildings. On each end, I have an APC Ethernet surge protector that is grounded to the main ground for each ...
0
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1answer
256 views

Linux network interface broadcast statistics

I am looking for a way to see the number of Ethernet broadcast frames transmit/received by the network interfaces. I am familiar with many Linux commands,procs and options to get interface statistics ...
0
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3answers
145 views

CentOS Network Interface Priorization

I have a CentOS server with 2 network interfaces with configurations: eth0: DEVICE=eth0 BOOTPROTO=none BROADCAST=10.0.0.255 HWADDR=xx: IPADDR=10.0.0.2 NETMASK=255.255.255.0 NETWORK=10.0.0.0 ...
4
votes
1answer
210 views

Is it possible to use WPA2 over ethernet?

Like, as in requesting a "password" to connect, just wondering. Also, are any of these (VPN, public key auth?) methods either possible or implemented?
3
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1answer
493 views

OpenVPN to host tap device having very large MTU

Question What is the minimum set of server and client configuration directives that I need in order to satisfy the following conditions? Virtual layer 2 ethernet network that will not be bridged ...
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3answers
1k views

Can Wireshark capture an entire Ethernet frame including preamble, CRC and Interframe spacing?

I am examining an Ethernet frame in Wireshark. According to the "Ethernet frame" Wikipedia article and accompanying diagrams, "A frame starts with a 7-octet preamble and 1-octet start frame delimiter ...
2
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0answers
543 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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1answer
117 views

Source and Destination Packets on Wireshark Relative or Absolute?

New in Packet Analysis. Sniffing on the Ethernet device of my computer. Does the Source and Destination columns on Wireshark tell the source and destination from where the packet was originated and ...
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2answers
97 views

Switch between network configurations via command line in fedora 17

I have two different setups I use on my work laptop; one enables synergy over an ethernet ssh tunnel with my work computer on the local network, and the other opens an HTTP tunnel to my work computer ...
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0answers
120 views

bonding - balance-tlb and a mysterious ethernet packet with lots of 00:00:00

Whilst attempting to get bonding working with mode=5 (balance-tlb) it seems that the driver sends an ethernet packet with length 0x0060 and the data, payload is all zeros. I can't work out where this ...
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2answers
226 views

Tunnel Ethernet Packets over SSH

I have two machines. My laptop and a machine in the local intranet. This machine has next to the network device (for the intranet) a second network card. I want to send raw ethernet frames out of this ...
3
votes
1answer
171 views

Missing Ethernet preamble [closed]

I am helping my colleague debug his problem. Basically, there are two 10M devices, and only one of which we have control over (the other being a "black box"). Analyzing the Ethernet hardware signals ...
0
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2answers
1k views

Is the 64-byte minimal Ethernet packet rule respected in practice?

A quick WireShark scan of my network interface reveals a bunch of Ethernet packets which are less than 64 bytes in length. I know that WireShark strips off the trailing 4 byte CRC, but I still see ...
0
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1answer
149 views

Enabling Ethernet X3530 M4

I have IBM X3530 M4, and it appears to have 4 ethernet ports, but under Ubuntu just 2 ethernet ports are enabled. How can I enable the other two ethernet ports?
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2answers
204 views

Extending a PaGP EtherChannel run beyond the maximum ethernet length [closed]

I have an office downstairs which requires approximately 500 feet of cat-5 to reach. We have a basic L2 switch in a closet at the halfway point which acts as a signal booster, and allows us to give ...
2
votes
2answers
169 views

How do fiber Ethernet transmitters set their power output?

I've noticed that fiber-optic SFP modules from Cisco and the like often specify a range of power outputs, such as -3 to -9 dBm. What determines the actual power output we should expect to see from ...
1
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1answer
157 views

Bond0 Failover when link light stays up: High Availability Network

Configuration: Two switches, each with a separate internet route Centos servers with eth0 and eth1 bonded as an active-backup on bond0, eth0 in on switch and eth1 in the other /etc/modprobe.conf ...
4
votes
3answers
628 views

Effect of reversing a pair, in cat5 cabling (e.g. swapping stripe and solid)

Is there any practical effect of reversing solid and stripe, when wiring cat5 cables? But if I've got a cable where each pair is a pair but one end is flipped, will this make any practical difference ...
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1answer
40 views

Calculation units in EtherType frame field [closed]

The EterType ethernet frame field value is represent a payload field length in bits or bytes?
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23 views

Interface eth0 not reacheble outside LAN

First of all, sorry for my bad english. I configured my two interfaces, eth0 and eth1! Bove have the LAN IP 192.168.0.10 and 192.168.0.11.... everything ok. The problem is, eth0 is reacheble from ...
3
votes
2answers
284 views

Need to “extend” wireless signal to conference room

We have a network set up using an ASUS RT-N66U for our office with the following configuration: Private SSID (one for 2.4 GHz and 5 GHz) Guest SSID (one for 2.4 GHz and 5 GHz) Unfortunately, we've ...
0
votes
1answer
83 views

obtain the MAC Address/interface name from GUI on FreeBSD?

Is there any way I can obtain the MAC Address/interface name from GUI on FreeBSD? Are there any system calls to do that? I was searching everywhere but couldn't find any information. Can you please ...
0
votes
1answer
61 views

How to build a L2 Ethernet with 1000 comupters?

We don't really have 1000 computers. I'm asking this question just because my brain is blocked here. If I put a number of, say 1000, computer on a L2 Ethernet. Since most of L2 switch has only maybe ...
0
votes
1answer
90 views

Multiple ethernet interface on one ethernet card

First I must say that I am new in linux and maybe I will ask trivial question. My job is to create 8 ethernet interface to be visible in kernel, but all of them should send and receive data through ...
6
votes
1answer
279 views

Why do metal fasteners (e.g., staples) around ethernet cables impair network performance? [closed]

At one point I was living in a 6 bedroom home that had cat 6 ethernet wired to each bedroom. The internet connection to the bedrooms furthest from the cable modem had terrible performance, though I ...
0
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1answer
335 views

troubleshoot Ethernet (layer 2) without layer 3

I am troubleshooting a LAN and the problem is to make sure each host can reach each other at layer 3. Each host is configured to the same subnet, but some hosts cannot reach other at layer 3 (e.g. ...
1
vote
1answer
38 views

Use or not to use multiple ips on the same network card?

I got a Dell r620 that cames with 4 network interfaces. If I have for example 4 ips, and want to assigne them to the server. What would be better, in terms of performance. Add all the 4 ips to the ...
4
votes
1answer
271 views

command for MAC broadcast

I am looking for a command to discover all hosts on the same LAN segment from a host with unassigned IP, default gateway, and subnet. I know there's ping 255.255.255.255 but that operates at layer 3 ...
3
votes
2answers
277 views

How can I make a secondary NIC port “eth0”?

I am using CentOS 5.9. One of my servers recently had a malfunctioning NIC port. The software running on the server was hard-coded to use eth0. The other physical NIC ports were fine and unused. The ...
4
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1answer
152 views

Supress FreeBSD “link down: cable prοblem?” messages

I have a FreeBSD lab machine that is regularly connected and disconnected from the network, sometimes to borrow the port temporarily for another machine and other times to test the ability of certain ...
0
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1answer
45 views

How to determine remote link speed?

I'm on a non-manageable switched 1 GbE network with mixed 100 MbE and 1 GbE hosts. Is it possible to tell if a certain host has a certain link speed without looking at the status LEDs of the switch ...
1
vote
1answer
678 views

ESXi5 - 12 Network Interfaces in Windows Guest

I am building a CCIE lab where I will use GNS3 to map virtual router interfaces to physical NIC interfaces which connect to physical switches. I want to build this in an ESXi5 Guest running Win 7. My ...
2
votes
1answer
169 views

How do I find out which pairs of a CAT5e cable are actually connected to another machine?

Using Linux (Debian, to be specific) on a laptop, I want to be able to check whether, for example, the TX or RX pairs are both connected to another machine. If, say, I've only connected RX (and am ...