A Network Interface Card is a computer component which connects to a physical network in order to send and receive data.
Questions tagged [nic]
615 questions
50
votes
6 answers
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 forward packets from eth0 to eth1.
I have…
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Kyle Coots
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48
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9 answers
How fast is 127.0.0.1?
I wonder if it is tied to my NIC at all or if the OS or driver intercepts and immediately returns data sent to the loopback address?
Does the signal actually travel to my NIC then the NIC returns it?
user55029
39
votes
3 answers
What is the command to flash a NIC link light?
I remember using a command line tool to flash a NIC's link light to identify it. I can't remember for the life of me what it was.
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rjmoggach
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7 answers
Can a single network card have 2 IP addresses?
Are network cards and IP addresses a one-one map?
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kernel
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Windows Server 2008: specifying the default IP address when NIC has multiple addresses
I have a Windows Server which has ~10 IP addresses statically bound. The problem is I don't know how to specify the default IP address.
Sometimes when I assign a new address to the NIC, the default IP address changes with the last IP entered in the…
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Cédric Boivin
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10 answers
Is there any reason to have 2 NICs on a server?
Is there any reason to have 2 NICs on a server BESIDES the following cases?
You need to connect to 2 different physical networks
Redudancy (1 NIC fails, so you use the other)
Are there any other reasons?
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noctonura
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5 answers
What network loads require NIC polling vs interrupts?
Does anyone have some data or basic calculations that can answer when frame coalescing (NAPI) is required and when a single interrupt per frame is sufficient?
My hardware: IBM BladeServer HS22, Broadcom 5709 Gigabit NIC hardware (MSI-X), with dual…
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Wim Kerkhoff
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5 answers
multiple physical interfaces with IPs on the same subnet
I have a linux box with 9 NICs on it, and I want eight of them to have unique addresses on the same subnet, e.g.:
ifconfig eth1 192.168.123.1 netmask 255.255.0.0
ifconfig eth2 192.168.123.2 netmask 255.255.0.0
ifconfig eth3 192.168.123.3 netmask…
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frustrated_tester
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PCIe x8 NIC in PCIe x16 slot
I have a motherboard with only one x16 PCIe slot and no x8 slots. I am buying a NIC with very specific configuration, but it is available for x8 slots only. Can I plug a x8 card in a x16 slot? I have googled this question and this seems quite…
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gmemon
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2 answers
What is the fall off of subsecond throughput on Ethernet Network Interfaces
On a network interface, speeds are given in term of data over time, in particular, they are bits per second. However, in the uber-fast world of computing -- a second is kind of a really long time.
So for example, given a linear falloff. A 1 GBit per…
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Kyle Brandt
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1 answer
How GRO (generic receive offload) works on more advanced NICs?
I am interested in particular answers:
Does the NIC with GRO edits/creates TCP ACK or any other packets (or is this feature transparent to receiver/sender TCP stacks)?
There should be a timeout/event when NIC should pass the "glued segments" to the…
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user389238
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eth0 NIC Link is Down repeating message in kernel log
I've noticed since few days ago that same repeating kind of messages occurs and I positively can say that nothing was intentionally changed (installed/uninstalled) in that period.
here's sample of /var/log/kern.log message:
Mar 30 06:32:45 aurora…
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Miloš Đakonović
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1 answer
Assign individual NIC to KVM guest
I have a server with 6 NICs installed and is running Ubuntu 12.04LTS. I want to setup 4 guest VMs using kvm. Now I want to assign 2 NICs for the host(1 Public IP and 1 private IP), and 1 NIC each to 4 guest VM(all private IP). How do I do…
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Bin S
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1 answer
NAPI vs Adaptive Interrupts
Could anyone please explain how two following technologies are used to mitigate interrupt overhead under high networking load?
Adaptive-rx/Adaptive-tx, and
NAPI;
I would appreciate an answer that explains the difference closer to linux kernel…
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user389238
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Multiple IP addresses per NIC
How can I have multiple IP addresses assigned to a single NIC? I remember doing this on Unix way back when. Can it be done on Windows?
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BIBD
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