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epsilones
Asked: 2015-07-23 02:23:27 +0800 CST

how many ethernet cards ?

  • 772

I want to use my computer as a router. So I checked how many ethernet card I have running : lspci | grep -i net. I got a single line ? Does it mean that I have only one "eth0" ethernet card ?

14.04

2 Answers

  1. Best Answer

    Yes, but more than 1 line does not mean more than 1 NIC. Example

    $ lspci | grep -i net
01:00.0 Ethernet controller: Broadcom Corporation NetXtreme II BCM5716 
01:00.1 Ethernet controller: Broadcom Corporation NetXtreme II BCM5716

    This is 1 NIC connected to eth0:0 and eth0:1 (so 2 IP adresses) that is a PCI device(!).

    There is a better command:

    $ifconfig | grep Ethernet
eth0      Link encap:Ethernet  HWaddr d4:ae:52:67:58:bd
eth0:0    Link encap:Ethernet  HWaddr d4:ae:52:67:58:bd
eth0:1    Link encap:Ethernet  HWaddr d4:ae:52:67:58:bd
eth1      Link encap:Ethernet  HWaddr d4:ae:52:67:58:be
eth1:0    Link encap:Ethernet  HWaddr d4:ae:52:67:58:be

    2 NICs both with more than 1 connection. "eth1" is a USB device though so not shown in the 1st command.

    --- from comments ip link is even better: 

    $ ip link
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 16436 qdisc noqueue state UNKNOWN
    link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
2: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc mq state UP qlen 1000
    link/ether {mac} brd ff:ff:ff:ff:ff:ff
3: eth1: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc mq state UP qlen 1000
    link/ether {mac} brd ff:ff:ff:ff:ff:f
    • 4

  2. lspci list alll PCI devices so if you have some old built in network card, or some usb cards it will not shown in the result, so to get more precise result try this:

    ifconfig -a | grep Ethernet

    Thanks for @gertvdijk note add the -a option to ifconfig to list all interfaces even if they are down

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