Información de red

Se me planteo la necesidad de saber si la tarjeta de red instalada en un servidor linux era de 10/100 o de 1Gb, pues aqui la respuesta

Listar interfaces de red

ifconfig -a | grep eth
eth0      Link encap:Ethernet  HWaddr 00:25:22:0e:27:f6

Ya sabemos que tenemos una tarjeta activa y su mac para saber de que clase es utilizaremos

sudo lshw -class network
-network       
description: Ethernet interface   
product: RTL8111/8168B PCI Express Gigabit Ethernet controller 
vendor: Realtek Semiconductor Co., Ltd.    
physical id: 0       
bus info: pci@0000:01:00.0
logical name: eth0        version: 03   
serial: 00:25:22:0e:27:f6    
size: 100MB/s 
capacity: 1GB/s     
width: 64 bits 
clock: 33MHz 
network 
description: Ethernet interface 
physical id: 1 
logical name: tap0 

Como podemos observar efectivamente la tarjeta es de 1GB/s ademas tiene asignado un nombre que es tap0

Si tenemos instalados las utilidades ethtool podemos visualizar mas información con:

ethtool eth0
Supported ports: [ TP MII ]
Supported link modes:   10baseT/Half 10baseT/Full  	                        
                        100baseT/Half 100baseT/Full
                        1000baseT/Half 1000baseT/Full  	
Supports auto-negotiation: Yes
Advertised link modes:  10baseT/Half 10baseT/Full  	                      
                        100baseT/Half 100baseT/Full
                        1000baseT/Half 1000baseT/Full  	
Advertised pause frame use: No 
Advertised auto-negotiation: Yes 
Link partner advertised link modes:  10baseT/Half 10baseT/Full                                                                           
                                     100baseT/Half 100baseT/Full 
Link partner advertised pause frame use: No 
Link partner advertised auto-negotiation: Yes 	
Speed: 100Mb/s 
Duplex: Full 
Port: MII 
PHYAD: 0 
Transceiver: internal 
Auto-negotiation: on 
Supports Wake-on: pumbg 
Wake-on: d 
Current message level: 0x00000033 (51) 
Link detected: yes