5.3.8. Networking

FreeBSD, as with Unix in general, places a big emphasis on networking. Therefore, even if you do not have an Ethernet card, pay attention to the mandatory options and the dial-up networking support.

options INET

Networking support. Leave it in even if you do not plan to be connected to a network. Most programs require at least loopback networking (i.e. making network connections within your PC) so this is essentially mandatory.

Ethernet cards

The next lines enable support for various Ethernet cards. If you do not have a network card, you can comment out all of these lines. Otherwise, you will want to leave in support for your particular Ethernet card(s):

device de0

Ethernet adapters based on Digital Equipment DC21040, DC21041 or DC21140 chips

device fxp0

Intel EtherExpress Pro/100B

device vx0

3Com 3C590 and 3C595 (buggy)

device cx0 at isa? port 0x240 net irq 15 drq 7 vector cxintr

Cronyx/Sigma multiport sync/async (with Cisco or PPP framing)

device ed0 at isa? port 0x280 net irq 5 iomem 0xd8000 vector edintr

Western Digital and SMC 80xx and 8216; Novell NE1000 and NE2000; 3Com 3C503; HP PC Lan Plus (HP27247B and HP27252A)

device el0 at isa? port 0x300 net irq 9 vector elintr

3Com 3C501 (slow!)

device eg0 at isa? port 0x310 net irq 5 vector egintr

3Com 3C505

device ep0 at isa? port 0x300 net irq 10 vector epintr

3Com 3C509 (buggy)

device fe0 at isa? port 0x240 net irq ? vector feintr

Fujitsu MB86960A/MB86965A Ethernet

device fea0 at isa? net irq ? vector feaintr

DEC DEFEA EISA FDDI adapter

device ie0 at isa? port 0x360 net irq 7 iomem 0xd0000 vector ieintr

AT&T StarLAN 10 and EN100; 3Com 3C507; unknown NI5210; Intel EtherExpress 16

device le0 at isa? port 0x300 net irq 5 iomem 0xd0000 vector le_intr

Digital Equipment EtherWorks 2 and EtherWorks 3 (DEPCA, DE100, DE101, DE200, DE201, DE202, DE203, DE204, DE205, DE422)

device lnc0 at isa? port 0x300 net irq 10 drq 0 vector lncintr

Lance/PCnet cards (Isolan, Novell NE2100, NE32-VL)

device ze0 at isa? port 0x300 net irq 5 iomem 0xd8000 vector zeintr

IBM/National Semiconductor PCMCIA ethernet controller.

device zp0 at isa? port 0x300 net irq 10 iomem 0xd8000 vector zpintr

3Com PCMCIA Etherlink III

Note: With certain cards (notably the NE2000) you will have to change the port and/or IRQ since there is no ``standard'' location for these cards.

pseudo-device loop

loop is the generic loopback device for TCP/IP. If you telnet or FTP to localhost (a.k.a. 127.0.0.1) it will come back at you through this pseudo-device. Mandatory.

pseudo-device ether

ether is only needed if you have an Ethernet card and includes generic Ethernet protocol code.

pseudo-device sl number

sl is for SLIP (Serial Line Internet Protocol) support. This has been almost entirely supplanted by PPP, which is easier to set up, better suited for modem-to-modem connections, as well as more powerful. The number after sl specifies how many simultaneous SLIP sessions to support. This handbook has more information on setting up a SLIP client or server.

pseudo-device ppp number

ppp is for kernel-mode PPP (Point-to-Point Protocol) support for dial-up Internet connections. There is also version of PPP implemented as a user application that uses the tun and offers more flexibility and features such as demand dialing. If you still want to use this PPP driver, read the kernel-mode PPP section of the handbook. As with the sl device, number specifies how many simultaneous PPP connections to support.

pseudo-device tun number

tun is used by the user-mode PPP software. This program is easy to set up and very fast. It also has special features such as automatic dial-on-demand. The number after tun specifies the number of simultaneous PPP sessions to support. See the user-mode PPP section of the handbook for more information.

pseudo-device bpfilter number

Berkeley packet filter. This pseudo-device allows network interfaces to be placed in promiscuous mode, capturing every packet on a broadcast network (e.g. an ethernet). These packets can be captured to disk and/or examined with the tcpdump(1) program. Note that implementation of this capability can seriously compromise your overall network security. The number after bpfilter is the number of interfaces that can be examined simultaneously. Optional, not recommended except for those who are fully aware of the potential pitfalls. Not all network cards support this capability.