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EP(4) Device Drivers Manual (i386) EP(4)


epEthernet driver for 3Com Etherlink III (3c5x9) interfaces


To compile this driver into the kernel, place the following line in your kernel configuration file:

device ep

Alternatively, to load the driver as a module at boot time, place the following line in loader.conf(5):



The ep driver is not present in FreeBSD 13.0 and later. See for more information.


The ep device driver supports network adapters based on the 3Com 3C5x9 Etherlink III Parallel Tasking chipset.

Various models of these cards come with a different assortment of connectors:

Standard 15 pin connector, also known as 10base5 (thick-net)
BNC, also known as thin-net
UTP, also known as twisted pair

The default port to use is the port that has been selected with the setup utility. To override this, use the following media options with ifconfig(8) or in your /etc/rc.conf file.

Use the AUI port.
Use the BNC port.
Use the UTP port.


The ep driver supports Ethernet adapters based on the 3Com 3C5x9 Etherlink III Parallel Tasking chipset, including:

  • 3Com 3C1 CF
  • 3Com 3C509-TP, 3C509-BNC, 3C509-Combo, 3C509-TPO, 3C509-TPC ISA
  • 3Com 3C509B-TP, 3C509B-BNC, 3C509B-Combo, 3C509B-TPO, 3C509B-TPC ISA
  • 3Com 3C562/3C563 PCMCIA
  • 3Com 3C574, 3C574TX, 3C574-TX, 3CCFE574BT, 3CXFE574BT, 3C3FE574BT PCMCIA
  • 3Com 3C589, 3C589B, 3C589C, 3C589D, 3CXE589DT PCMCIA
  • 3Com 3CXE589EC, 3CCE589EC, 3CXE589ET, 3CCE589ET PCMCIA
  • 3Com Megahertz 3CCEM556, 3CXEM556, 3CCEM556B, 3CXEM556B, 3C3FEM556C PCMCIA
  • 3Com OfficeConnect 3CXSH572BT, 3CCSH572BT PCMCIA
  • Farallon EtherWave and EtherMac PC Card (P/n 595/895 with BLUE arrow)


The 3c509 card has no jumpers to set the address. 3Com supplies software to set the address of the card in software. To find the card on the ISA bus, the kernel performs a complex scan operation at IO address 0x110. Beware! Avoid placing other cards at that address!

Furthermore, the 3c509 should not be configured in EISA mode.

Cards in PnP mode may conflict with other resources in the system. Ensure your BIOS is configured correctly to exclude resources used by the 3c509, especially IRQs, to avoid unpredictable behavior.

Many different companies sold the 3Com PC Cards under their own private label. These cards also work.

The Farallon EtherWave and EtherMac card came in two varieties. The ep driver supports the 595 and 895 cards. These cards have the blue arrow on the front along with a 3Com logo. The Farallon 595a cards, which have a red arrow on the front, are also called EtherWave and EtherMac. They are supported by the sn(4) driver.


ep0: reset (status: %x)
The driver has encountered a FIFO underrun or overrun. The driver will reset the card and the packet will be lost. This is not fatal.
ep0: eeprom failed to come ready
The eeprom failed to come ready. This probably means the card is wedged.
ep0: 3c509 in test mode. Erase pencil mark!
This means that someone has scribbled with pencil in the test area on the card. Erase the pencil mark and reboot. (This is not a joke).
ep0: No I/O space?!
The driver was unable to allocate the I/O space that it thinks should be there. Look for conflicts with other devices.
ep0: No irq?!
The driver could not allocate the interrupt it wanted. Look for conflicts, although sharing interrupts for PC Card is normal.
ep0: No connectors!
The driver queried the hardware for what ethernet attachment were present, but the hardware reported none that the driver recognized.
ep0: Unable to get Ethernet address!
The driver was unable to read the ethernet address from the EEPROM. This is likely the result of the card being wedged.
ep0: if_alloc() failed
The driver was unable to allocate a ifnet structure. This may happen in extremely low memory conditions.
ep0: strange connector type in EEPROM: assuming AUI
The driver does not know what to do with the information the EEPROM has about connectors, so it is assuming the worst.
ep0: unknown ID 0xXXXXXXXX
The driver has found an ID that it believes it supports, but does not have a specific identification string to present to the user.
ep0: <%s> at port 0x%03x in EISA mode, ignored.
The 3C509 ISA card is in EISA mode. The card will be ignored until it is taken out of EISA mode.
ep0: <%s> at x0%03x in PnP mode
This card appears to be in Plug and Play mode. It should be probed as part of the plug and play phase of the ISA probes.
ep0: Invalid EEPROM checksum!
The EEPROM has a bad checksum, so the driver is ignoring the card.
ep0: bus_setup_intr() failed!
The driver was unable to setup the interrupt handler. This should never happen.


altq(4), ed(4), intro(4), ng_ether(4), sn(4), vx(4), ifconfig(8)


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October 24, 2018 Debian