Questions tagged [nic]
A Network Interface Card is a computer component which connects to a physical network in order to send and receive data.
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IPv6 NAT information leakage [closed]
Edit: Since I was asked to edit this, I'll ask about an awfully specific issue. The question was obviously never about information leakage on OSI layer 7, since that wouldn't be a network issue.
I'm ...
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1
answer
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2+ PORT NIC Explained
I am very confused about two or more port network interface cards (NICs).
Does having 2 port on a NIC allow you to have 2 network interfaces? If I go to ifconfig will it list each port as a separate ...
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1
answer
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Under volumetric DDoS can I prevent ISP null-routing by turning NIC off briefly?
A server in a data center is getting a volumetric DDoS attack. Congestion starts to build up and the data center/ISP going to solve this by null-routing (RTBH routing) the server's IP address for ...
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3
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Is it possible to have same MAC address on multiple NICs plugged to same Linux computer?
Can I have multiple NICs in one computer, having same MAC address? OS - Ubuntu Linux.
Thanks
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1
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How to connect two EC2 instances using the eth1 interface on both instances?
I have 2 EC2 instances running Ubuntu 18.04. I've attached an additional network interface "eth1" to each instance, so each instance has 2 interfaces( eth0, eth1). eth0 is the default gateway.
What I'...
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0
answers
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Communicating with identical IP addresses on many distinct networks [closed]
I would like to be able to connect to a small group of networked hardware (let's call it a Rack) via a switch and a NIC in a Windows 10 Pro computer. The system hardware has fixed 192.168.0.x ...
1
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1
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Why is Debian 9 switching active nics on reboot?
I have been using Debian for years in a production environment. Installations changing from Jessy to Stretch I have noticed that now the NIC's take on non traditional names. They are no longer eth0, ...
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0
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Getting a static MAC address on AWS EC2
I want to ensure that my AWS EC2 instance has a static MAC address (for an app that ties the license to the MAC address). From what I read I just need to add an ENI to the instance to get a static ...
1
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1
answer
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PCI-E lane speed vs NIC throughput
I am curious about NIC troughput vs PCIE slot speed.
I have found Mellanox MHQH19B-XTR which claims to be 40 Gbps PCI-E 2.0 x8 cards.
However, this slot limit seems to be theoretical ~ 31 Gbps.
So, ...
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0
answers
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How do I get a server to host a private network
I am trying to set up a private network.
Box A is connects to a router which is connected to the internet, is a webserver, and is also the router for a private network. Box A is wireless connections ...
1
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1
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How do I remove the VLAN ID from my NIC (Netadapter)
So I am running a Windows 2019 datacenter server core running hyper-v which has a
Broadcom Gigabit Ethernet BCM5720 NIC with 2 access ports. The Server is patched into a VLAN.
So earlier on I ...
1
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1
answer
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"Cannot set device ring parameters: Operation not supported"
I'm trying to change the RX and TX for an HP BL460C server by using ethtool and get the following:
ethtool -G eth0 rx 4078 tx 4078
Cannot set device ring parameters: Operation not supported
My ...
1
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0
answers
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Ubuntu Server 18.04 two NIC on same subnet
I have Ubuntu Server 18.04 with 2 NIC cards installed and both of them have static IP assigned via netplan.
This is my config:
root@box2:/etc/netplan# cat 01-netcfg.yaml
network:
version: 2
...
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2
answers
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promiscuous mode when i run wireshark [closed]
I am running Ubuntu Linux and had installed Wireshark on it. I can see the incoming and outgoing traffic just fine. but as you know when you run Wireshark your nic should be on promiscuous mode.
...
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0
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Multihomed Ubuntu 14 using "internally optimized routing"
I have an Ubuntu 14 server which is multihomed with two identical 1Gb network cards.
The physical subnet routing is handled by another department. As such, when I want to add a new machine (or NIC) ...
2
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1
answer
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Load balancing multiple NICs on single machine presenting a virtual IP
I've inherited a network setup, where the NFS/Samba linux RAID server ("Ubuntu 14.04.5 LTS") is serving everything over one NIC. As a result, the 1Gb network bandwidth is saturated.
Unfortunately, ...
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2
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Simple manual load balancing
We're running a Windows 2016 AD server (ATLB-SRV01.atlb.local) that includes two NICs.
We have assigned each NIC a different IP and give them a proper name in the DNS server (type A record).
Example:...
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1
answer
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Windows machine with 2 NICs
I have 2 networks connected to my work PC, we'll call them NET1 and NET2. NET1 has internet access and NET2 doesn't.
NET1 is a work network which I have no control over.
My work computer is ...
1
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1
answer
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Transfer Speed Limited by Fileserver?
We have a 4gbit teamed nic fileserver that hosts smb shares.
The files it accesses are from an ISCI NAS drive which is 10gbit.
Will transfer speeds be limited by the file server? Or does the ISCI "...
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1
answer
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Gigabit modem to switch gigabit uplink?
Times change, and we are adapting to now having gigabit internet service at a local charity. Since there is a gigabit uplink on the switch already in place (Netgear FSM726) I was wondering if the ...
2
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1
answer
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Uninstall TCP/IPv4 (Server 2016)
In Microsoft Windows Server 2016 Datacenter there is a properties window for network interfaces, inside that properties window there are several checkboxes that control protocols. (Internet Protocol ...
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2
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How to specify a NIC number in virsh/kvm?
Hoping I can get some help here. I am using the virt-clone command to get an image of VyOS (open source linux router). The clone works fine but when I copy the image to another KVM host and install ...
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1
answer
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bonded ethernet NFS use both NIC's possible?
I have a box with two 1Gb NIC's in it, bonded. The type of bonding is "per connection" so each connection goes "to 1 nic" but if a process has multiple connections, it will share the bonded NIC's and ...
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1
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Dual Interface Network Card Issue on 2nd NIC
I'm working on reconfiguring an existing production server and having trouble with a dual port Intel PCIe card. It's running CentOS 6.4 [2.6.32-358.23.2.el6.x86_64] and it seems like it's a driver ...
3
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1
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What does rx_csum_offload_errors mean?
I see too many rx_csum_offload_errors on ethtool output and it constantly increases. What is the reason of these errors and how can I fix it?
# ethtool -S enp12s0f0 | grep error
rx_errors: 0
...
1
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1
answer
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Interface Masters Niagara 32264 Bypass Mode issues
We have several deployments of ClearOS 7 servers (hardware: Dell PowerEdge T30) on our clients' networks functioning as gateways. Recently I've been having a problem getting the Interface Masters ...
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2
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Multi-NIC Linux VM (ubuntu 16.04 LTS) in Azure and default gateway route
Can some one please share steps on how to add default gateway address route permanently to the route table on Ubuntu 16.04 LTS on Azure for the secondary nic?
As you know Azure DHCP only populate ...
0
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1
answer
2k
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iptables Source NAT with Multiple NIC & Public IP Addresses Not Working
I just have a problem on the multiple NIC & IP addresses server. I've configured my Cent OS 7 server with an additional public IP address which belongs to eth1. When iptables source NAT enabled, ...
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1
answer
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linux port forwarding between two nics [closed]
I have a vicidial server running on suse. I have installed two nic cards. One nic connects to my local network and the other connects to the firewall. The config is as below:
Nic 1 : 192.168.2.21 (...
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0
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How to change default gateway nic?
My /etc/network/interfaces looks like this:
# The primary network interface
allow-hotplug enp3s0
iface enp3s0 inet dhcp
# iface enp3s0 inet6 dhcp
# USB 3.0 Gigabit Ethernet
allow-hotplug ...
0
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0
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How to connect two different networks hosted on 2 different NICs
I have a Windows 2012 R2 server which has 4 NICs. Two of these NICs are connected to seperate private networks(not connected to internet). NIC3 is connected to 192.168.137.1 (Subnet mask: 255.255.255....
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1
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ESXi VMs randomly lose network on reboot; only resolution to pull NICs and reassign new NIC driver with static MAC
We have one ESXi server (HP-ESXi-6.0.0 build-2492585) that has multiple VMs on it that have exhibited the following behavior:
When the VM is rebooted it will occasionally just lose all network ...
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1
answer
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How to rotate IPs using iptables having 2 NICs
I have 2 network interfaces in an ec2 linux server (eth0 eth1). After configuring the second NI (eth1), I'm able to ping both public IPs from eth0 and eth1 as to connect through SSH.
Now, my idea is ...
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1
answer
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How can I configure a storage server to provide data delivery on two separate networks?
I have a storage server with two NICs - each with two ports. The one NIC is 1 GbE, the other is 10 GbE.
I have a 10 GbE switch and have Cat6a running from the two 10 GbE ports into the 10 GbE switch.
...
3
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1
answer
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What is the term for assigning multiple IP addresses to single NIC within the same network?
I've been looking for the term used to define the process of assigning multiple IP addresses to single IP address. A similar term that I found so far is Multihoming but, this isn't quite what I'm ...
0
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0
answers
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Multiple NIC on same subnet with one port disconnected
I have a Linux system with 3 dedicated NICs & all 3 are on the same subnet with the following IPs
ETH0: 192.168.1.10
ETH1: 192.168.1.11
ETH2: 192.168.1.12
I've setup three routing tables & ...
0
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1
answer
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Ghost ping on a multi-NIC Linux system
I have a Linux system with 3 NICs & all 3 are on the same subnet. I've setup policy routing on the system with ip rules & ip routes using 3 tables. These are the IPs of the 3 NICs.
ETH0: 192....
1
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1
answer
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Port forwarding by MAC address problems
I have a server sitting behind a Huawei HG569 router. Port forwarding has been set up through the router and, when it works, it works as one would expect.
Now, the problem is that the HG569 router ...
3
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2
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Hyper-V 2016 Server and NIC Teaming
I am setting up a new Hyper-V 2016 server. The physical machine has 6 network ports. I read that it is best practice to have one network port dedicated to remote management of the Hyper-V Host, so ...
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1
answer
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Change External NIC to Public on Windows Server 2016
I've got a cloud network: 192.168.100.0/24 with:
Pfsense GW (IPSec site-to-site)
NIC1 = WAN-IP1 (fully blocked except IPSec)
NIC2 = 192.168.100.1
DC (WinServer2016)
NIC1 = WAN-IP2 (external)
NIC2 = ...
2
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0
answers
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Why does my Realtek gigabit NIC not advertise 1000Mbit mode?
I currently have a NAS (openmediavault based on debian) with a Realtek gigabit NIC (ASRock Q1900-ITX on-board LAN), but it won't advertise that it is gigabit-capable. ethtool eth0 gives the following ...
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1
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NIC suddenly doesn't recognize cable
I have a server lab with an ASROCK motherboard. Built this server about 6 months ago.
Today, while working on it, the NIC Local Area Connection (Ethernet) suddenly showed that the cable is unplugged....
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1
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Connect to sshd over direct link to second NIC
This is how things are by default. I did not set anything up.
My debian server has a network connection on eno2 with ip 192.168.1.40. Internet, sshd, Everything works fine.
Now I've added a second ...
7
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3
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Multiport Server NIC ports?
I need to buy multiport NIC, because I need to replace 4 NIC with one. For example they are:
https://www.amazon.com/HP-NC364T-Gigabit-Server-Adptr/dp/B000P0NX3G
https://www.amazon.com/Intel-1000-...
3
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0
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What do the numbers in square brackets of ethtool output mean?
I'm looking at NIC statistics and can't find any info about these numbers: [0],[1]..[7] like here:
[root@machine-1 ~]# ethtool -S enp21s0f0
NIC statistics:
[0]: rx_bytes: 23048043995115
[0]:...
1
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1
answer
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Does it make sense to use dynamic mode with switch depentent mode?
According to the NIC teaming tutorial of itfreetraining on youtube, in the NIC teaming mode "dynamic", outbound traffic is distributed among the team members using the address hash method and inbound ...
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1
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Right network interface autodetect and get dhcp while boot
While preparing the mini forensic system I hung on a problem:
Let us imagine, we prepare a usb-flash booted linux for lot of diferent workstations. While setting up the network (ipv4 dhcp) we can find ...
0
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0
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Centos 7 with two NIC cards getting random availability after reboot
I have a Centos 7 installed on vSphere with two Nic (eth0 and eth1)
eth0 - 10.10.1.1
eth2 - 192.168.1.1
both IP assigned by DHCP.
When reboot server first time - eth0 (10.10.1.1) is responding for ...
2
votes
1
answer
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when should I raise an alarm if I see dropped packets ( packet_in or packet_out)
I am trying to create a simple anomaly alarm detection by looking at the KPI of my Linux servers. I was wondering when should I flag an alarm if see dropped packets ( both packet_in and/or packet_out)....
0
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1
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Intel Network Card on Linux server - limited performance despite bonding ports
I took over a Debian 7 server with an Intel NIC where the ports are bonded together for load balancing. This is the hardware:
lspci -vvv | egrep -i 'network|ethernet'
04:00.0 Ethernet controller: ...