Nomenclatura estranha, essa das portas (p255pX). Foi você que escolheu assim? Esse servidor é físico ou virtual?
Execute mais dois comandos por favor.
sudo lshw -C network
ethtool p255p1
O servidor é físico e o nome foi atribuído pelo Ubuntu (14.04.2). Como sou novato por as bandas do Unbuntu server, procurei por todo o lado, reinstalei-o por duas vezes e não encontrava a placa de rede, até que andei a fuçar mais um pouco e num dos comandos descobri os nomes das placas (p255p1 e p255p2).
sudo lshw -C network
*- Network:0
description: Ethernet interface
product: I350 Gigabit Network Connection
vendor: Intel Corporation
physical id: 0
bus info: pci@0000:04:00.0
logical name: p255p1
version: 01
serial: 00:25:90:a5:91:7a
capacity: 1Gbit/s
width: 32 bits
clock: 33MHz
capabilities: pm msi msix pciexpress bus_master cap_list ethernet physical tp 10bt 10bt-fd 100bt 100bt-fd 1000bt-fd autonegociation
configuration: autonegotiation=on broadcast=yes driver= igb driverversion=5.0.5-k firmware=1.61, 0x8000090e ip=10.113.164.1 latency=0 link=no multicast=yes port=twisted pair
resoureces: irq:27 memory:fb920000-fb93ffff ioport:d020(size=32) memory:fb944000-fb947fff memory:faa40000-faa5ffff
*- Network:1 DISABLE
description: Ethernet interface
product: I350 Gigabit Network Connection
vendor: Intel Corporation
physical id: 0.1
bus info: pci@0000:04:00.0.1
logical name: p255p2
version: 01
serial: 00:25:90:a5:91:7b
capacity: 1Gbit/s
width: 32 bits
clock: 33MHz
capabilities: pm msi msix pciexpress bus_master cap_list ethernet physical tp 10bt 10bt-fd 100bt 100bt-fd 1000bt-fd autonegociation
configuration: autonegotiation=on broadcast=yes driver= igb driverversion=5.0.5-k firmware=1.61, 0x8000090e latency=0 link=no multicast=yes port=twisted pair
resoureces: irq:30 memory:fb900000-fb91ffff ioport:d000(size=32) memory:fb940000-fb943fff memory:faa20000-faa1ffff
ethtool p255p1
Supported ports: [ TP ]
Supportes link modes: 10baseT/Half 10baseT/Full
100baseT/Half 100baseT/Full
1000baseT/Full
Supported pause frame use: Symmetric
Supports auto-negotiation: Yes
Advertised link modes: 10baseT/Half 10baseT/Full
100baseT/Half 100baseT/Full
1000baseT/Full
Supported pause frame use: Symmetric
Supports auto-negotiation: Yes
Speed: Unknown!
Duplex: Unknown! (255)
Port: Twisted Pair
PHYAD: 1
Transceiver: internal
Auto-negotiation: on
MDI-X:off (auto)
Cannot get wave-on-lan settings: Operation no permitted
Current mwessage level: 0x00000007 (7)
drv prove link
Link detected:no
Agradeço desde já a atenção dispensada.