Network interface - Revision history

Pbug at 12:40, 13 October 2005

2005-10-13T12:40:02Z

← Older revision		Revision as of 05:40, 13 October 2005
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	If you want to be sure that traffic is being routed or bridged you can attach a [[bpf]] program like tcpdump to a network interface and watch a packet entering interface a and exiting on interface b.		If you want to be sure that traffic is being routed or bridged you can attach a [[bpf]] program like tcpdump to a network interface and watch a packet entering interface a and exiting on interface b.

			Network interfaces are distinguished by a type, ie. lo, xl, wi, pppoe, ppp, tun, and so on, and a network interface number in case there is more than one of it's type ie. lo0, lo1, lo2.

			The length of an interface name in [[OpenBSD]] is limited by IFNAMSIZ (16) which is found in ''/usr/include/net/if.h''.

Pbug at 12:35, 13 October 2005

2005-10-13T12:35:52Z

← Older revision		Revision as of 05:35, 13 October 2005
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	A network interface is the interface to a network node or a certain Network Interface Card (NIC) perhaps an ~~Ethernet~~ card. An interface can be virtual or physical. To see all network interfaces on a system use the [[ifconfig]] command.		A network interface is the interface to a network node or a certain Network Interface Card (NIC) perhaps an [[ethernet]] card. An interface can be virtual or physical. To see all network interfaces on a system use the [[ifconfig]] command.


	$ ifconfig -a		$ ifconfig -a
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	inet6 fe80::260:8ff:fe5a:8682%xl0 prefixlen 64 scopeid 0x2		inet6 fe80::260:8ff:fe5a:8682%xl0 prefixlen 64 scopeid 0x2

	When a computer has multiple network interfaces and passes [[IP]] traffic from one interface to another interface it is called a [[router]]. Similarely if a computer passes [[~~Ethernet~~]] frames from one NIC to another it is called a [[bridge]].

			When a computer has multiple network interfaces and passes [[IP]] traffic from one interface to another interface it is called a [[router]]. Similarely if a computer passes [[ethernet]] frames from one NIC to another it is called a [[bridge]].

	If you want to be sure that traffic is being routed or bridged you can attach a [[bpf]] program like tcpdump to a network interface and watch a packet entering interface a and exiting on interface b.		If you want to be sure that traffic is being routed or bridged you can attach a [[bpf]] program like tcpdump to a network interface and watch a packet entering interface a and exiting on interface b.

Pbug at 12:22, 13 October 2005

2005-10-13T12:22:56Z

New page

A network interface is the interface to a network node or a certain Network Interface Card (NIC) perhaps an Ethernet card. An interface can be virtual or physical. To see all network interfaces on a system use the [[ifconfig]] command.

$ ifconfig -a
lo0: flags=8049<UP,LOOPBACK,RUNNING,MULTICAST> mtu 33192
groups: lo
inet 127.0.0.1 netmask 0xff000000
inet6 ::1 prefixlen 128
inet6 fe80::1%lo0 prefixlen 64 scopeid 0x9
wi0: flags=8843<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST> mtu 1500
lladdr 00:02:2d:09:4b:44
media: IEEE802.11 autoselect (DS2)
status: active
ieee80211: nwid ATLAS -12dBm (auto)
inet 10.0.0.2 netmask 0xff000000 broadcast 10.255.255.255
inet6 fe80::202:2dff:fe09:4b44%wi0 prefixlen 64 scopeid 0x1
xl0: flags=8843<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST> mtu 1500
lladdr 00:60:08:5a:86:82
media: Ethernet 100baseTX full-duplex
status: no carrier
inet 172.16.2.2 netmask 0xfffffe00 broadcast 172.16.3.255
inet6 fe80::260:8ff:fe5a:8682%xl0 prefixlen 64 scopeid 0x2

When a computer has multiple network interfaces and passes [[IP]] traffic from one interface to another interface it is called a [[router]]. Similarely if a computer passes [[Ethernet]] frames from one NIC to another it is called a [[bridge]].

If you want to be sure that traffic is being routed or bridged you can attach a [[bpf]] program like tcpdump to a network interface and watch a packet entering interface a and exiting on interface b.