目录
![]() |
提示 |
---|---|
關於GNU/Linux網絡的通用手冊,請查看Linux 網絡管理員手冊。 |
![]() |
提示 |
---|---|
關於Debian專屬的網絡手冊,請查看Debian管理員手冊—網絡配置。 |
![]() |
警告 |
---|---|
Instead of using the traditional interface naming scheme
(" |
![]() |
警告 |
---|---|
本章是基於 2013 年發佈的 Debian 7.0 ( |
![]() |
提示 |
---|---|
儘管本手冊仍用舊的
ifconfig(8)
命令和IPv4協議當作網絡配置的例子,Debian在 |
讓我們來回顧一下現代Debian操作系統中的基本網絡架構。
表 5.1. 網絡配置工具一覽表
軟件包 | 流行度 | 大小 | 類型 | 說明 |
---|---|---|---|---|
ifupdown
|
V:566, I:995 | 204 | 配置::ifupdown | 用來啓動/關閉網絡的標準工具(Debian特有) |
ifplugd
|
V:4, I:19 | 209 | 同上 | 自動管理有線網絡 |
ifupdown-extra
|
V:0, I:1 | 96 | 同上 |
網絡測試腳本,加強"ifupdown "軟件包的功能
|
ifmetric
|
V:0, I:1 | 36 | 同上 | 設置網絡接口的路由度量 |
guessnet
|
V:0, I:1 | 402 | 同上 |
腳本文件,利用"/etc/network/interfaces "文件來加強"ifupdown "的功能
|
ifscheme
|
V:0, I:0 | 58 | 同上 |
映射腳本文件,增強"ifupdown "軟件包的功能
|
ifupdown-scripts-zg2
|
V:0, I:0 | 147 | 同上 | Zugschlus寫的腳本,用於ifupdown手動管理 |
network-manager
|
V:367, I:472 | 11192 | 配置::NM | NetworkManager(守衛進程):自動管理網絡 |
network-manager-gnome
|
V:246, I:416 | 6132 | 同上 | NetworkManager(GNOME前端) |
wicd
|
I:34 | 34 | 配置::wicd | 有線和無線網絡管理器(元軟件包) |
wicd-cli
|
V:0, I:2 | 58 | 同上 | 有線和無線網絡管理器(命令行客戶端) |
wicd-curses
|
V:1, I:5 | 174 | 同上 | 有線和無線網絡管理器(文本界面客戶端) |
wicd-daemon
|
V:30, I:39 | 951 | 同上 | 有線和無線網絡管理器(守護進程) |
wicd-gtk
|
V:24, I:36 | 573 | 同上 | 有線和無線網絡管理器(GTK+客戶端) |
iptables
|
V:243, I:993 | 1525 | 配置::Netfilter | 封包過濾和網絡地址轉換管理工具(Netfilter) |
iproute
|
V:134, I:531 | 23 | 配置::iproute2 | iproute2, IPv6和其他高級網絡配置:ip(8),tc(8)等等 |
ifrename
|
V:0, I:2 | 121 | 同上 | 根據不同的靜態標準來重命名網絡接口:ifrename(8) |
ethtool
|
V:93, I:263 | 331 | 同上 | 顯示或更改以太網設備的設定 |
iputils-ping
|
V:262, I:996 | 111 | 測試::iproute2 | 測試能否連接遠程主機,通過主機名或IP 地址(iproute2) |
iputils-arping
|
V:67, I:390 | 58 | 同上 | 測試能否連接遠程主機,通過ARP地址 |
iputils-tracepath
|
V:17, I:288 | 75 | 同上 | 跟蹤訪問遠程主機的路徑 |
net-tools
|
V:421, I:998 | 934 | 配置::net-tools | NET-3網絡工具箱(net-tools,IPv4網絡配置):ifconfig(8)等等。 |
inetutils-ping
|
V:0, I:1 | 337 | 測試::net-tools | 測試能否連接遠程主機,通過hostname或IP 地址(傳統方式,GNU) |
arping
|
V:2, I:28 | 103 | 同上 | 測試能否連接遠程主機,通過ARP地址(傳統方法) |
traceroute
|
V:75, I:992 | 154 | 同上 | 跟蹤連接遠程主機的路徑(傳統方法,控制檯) |
isc-dhcp-client
|
V:421, I:960 | 651 | 配置::底層 | DHCP客戶端 |
wpasupplicant
|
V:292, I:547 | 2531 | 同上 | WPA和WPA2客戶端支持(IEEE 802.11i) |
wpagui
|
V:0, I:4 | 781 | 同上 | wpa_supplicant Qt 圖形界面客戶端 |
wireless-tools
|
V:86, I:276 | 265 | 同上 | 操控Linux無線擴展的工具 |
ppp
|
V:177, I:519 | 927 | 同上 |
使用chat 連接PPP/PPPoE
|
pppoeconf
|
V:0, I:12 | 290 | 配置::輔助 | 配置助手,以便於使用PPPoE連接 |
pppconfig
|
V:1, I:4 | 805 | 同上 |
配置助手,以便於使用chat 連接PPP
|
wvdial
|
V:0, I:8 | 276 | 同上 |
配置助手,以便於使用wvdial 和ppp 連接PPP
|
mtr-tiny
|
V:7, I:60 | 105 | 測試::底層 | 追蹤連接遠程主機的路徑(文本界面) |
mtr
|
V:6, I:40 | 150 | 同上 | 追蹤連接遠程主機的路徑(文本界面和GTK+界面) |
gnome-nettool
|
V:14, I:283 | 2111 | 同上 | 獲取常見網絡信息的工具(GNOME) |
nmap
|
V:50, I:452 | 22296 | 同上 | 網絡映射/端口掃描(Nmap,控制檯) |
zenmap
|
V:3, I:12 | 2824 | 同上 | 網絡映射/端口掃描(GTK+) |
tcpdump
|
V:22, I:198 | 1153 | 同上 | 網絡流量分析(Tcpdump,控制檯) |
wireshark
|
V:5, I:65 | 74 | 同上 | 網絡流量分析(Wireshark,GTK+) |
tshark
|
V:3, I:37 | 365 | 同上 | 網絡流量分析(控制檯) |
nagios3
|
I:8 | NOT_FOUND | 同上 | 主機、服務、網絡監控及管理系統(Nagios) |
tcptrace
|
V:0, I:1 | 392 | 同上 |
根據tcpdump 的輸出生成的連接數據統計
|
snort
|
V:1, I:1 | 1920 | 同上 | 靈活的網絡入侵偵測系統(Snort) |
ntopng
|
V:0, I:1 | 578 | 同上 | 在網頁瀏覽器中展示網絡流量 |
dnsutils
|
V:90, I:901 | 462 | 同上 | BIND軟件包提供的網絡客戶端程序:nslookup(8),nsupdate(8),dig(8) |
dlint
|
V:1, I:22 | 96 | 同上 | 利用域名服務器查詢來查看DNS域信息 |
dnstracer
|
V:0, I:2 | 56 | 同上 | 跟蹤DNS查詢直至源頭 |
The hostname resolution is currently supported by the NSS (Name Service Switch) mechanism too. The flow of this resolution is the following.
The "/etc/nsswitch.conf
" file with stanza like
"hosts: files dns
" dictates the hostname resolution
order. (This replaces the old functionality of the
"order
" stanza in "/etc/host.conf
".)
The files
method is invoked first. If the hostname is
found in the "/etc/hosts
" file, it returns all valid
addresses for it and exits. (The "/etc/host.conf
" file
contains "multi on
".)
The dns
method is invoked. If the hostname is found by
the query to the Internet Domain
Name System (DNS) identified by the
"/etc/resolv.conf
" file, it returns all valid addresses
for it and exits.
For example, "/etc/hosts
" looks like the following.
127.0.0.1 localhost 127.0.1.1 <host_name> # The following lines are desirable for IPv6 capable hosts ::1 ip6-localhost ip6-loopback fe00::0 ip6-localnet ff00::0 ip6-mcastprefix ff02::1 ip6-allnodes ff02::2 ip6-allrouters ff02::3 ip6-allhosts
Each line starts with a IP address and it is followed by the associated hostname.
The IP address 127.0.1.1
in the second line of this
example may not be found on some other Unix-like systems. The Debian Installer creates this entry for a
system without a permanent IP address as a workaround for some software
(e.g., GNOME) as documented in the bug
#719621.
The <host_name> matches the hostname defined in the
"/etc/hostname
".
For a system with a permanent IP address, that permanent IP address should
be used here instead of 127.0.1.1
.
For a system with a permanent IP address and a fully qualified domain name (FQDN) provided by the Domain Name System (DNS), that canonical <host_name>.<domain_name> should be used instead of just <host_name>.
The "/etc/resolv.conf
" is a static file if the
resolvconf
package is not installed. If installed, it is
a symbolic link. Either way, it contains information that initialize the
resolver routines. If the DNS is found at
IP="192.168.11.1
", it contains the following.
nameserver 192.168.11.1
The resolvconf
package makes this
"/etc/resolv.conf
" into a symbolic link and manages its
contents by the hook scripts automatically.
For the PC workstation on the typical adhoc LAN environment, the hostname
can be resolved via Multicast DNS (mDNS, Zeroconf) in addition to the basic
files
and dns
methods.
Avahi provides a framework for Multicast DNS Service Discovery on Debian.
It is equivalent of Apple Bonjour / Apple Rendezvous.
The libnss-mdns
plugin package provides host name
resolution via mDNS for the GNU Name Service Switch (NSS) functionality of
the GNU C Library (glibc).
The "/etc/nsswitch.conf
" file should have stanza like
"hosts: files mdns4_minimal [NOTFOUND=return] dns mdns4
".
Host names ending with the ".local" pseudo-top-level domain (TLD) are resolved.
The mDNS IPv4 link-local multicast address "224.0.0.251
"
or its IPv6 equivalent "FF02::FB
" are used to make DNS
query for a name ending with ".local
".
The hostname resolution via deprecated NETBios over TCP/IP used by the older
Windows system can be provided by installing the winbind
package. The "/etc/nsswitch.conf
" file should have
stanza like "hosts: files mdns4_minimal [NOTFOUND=return] dns mdns4
wins
" to enable this functionality. (Modern Windows system
usually use the dns
method for the hostname resolution.)
![]() |
注意 |
---|---|
The expansion of generic Top-Level Domains (gTLD) in the Domain Name System is underway. Watch out for the name collision when chosing a domain name used only within LAN. |
The network interface name, e.g. eth0
, is assigned to
each hardware in the Linux kernel through the user space configuration
mechanism, udev
(see 第 3.3 节 “The udev system”),
as it is found. The network interface name is referred as physical interface in
ifup(8)
and
interfaces(5).
In order to ensure each network interface to be named persistently for each
reboot using MAC address etc., there is a
rules file "/etc/udev/rules.d/70-persistent-net.rules
".
This file is automatically generated by the
"/lib/udev/write_net_rules
" program, probably run by the
"persistent-net-generator.rules
" rules file. You can
modify it to change naming rule.
![]() |
小心 |
---|---|
When editing the
" |
Let us be reminded of the IPv4 32 bit address ranges in each class reserved for use on the local area networks (LANs) by rfc1918. These addresses are guaranteed not to conflict with any addresses on the Internet proper.
表 5.2. List of network address ranges
Class | network addresses | net mask | net mask /bits | # of subnets |
---|---|---|---|---|
A | 10.x.x.x | 255.0.0.0 | /8 | 1 |
B | 172.16.x.x — 172.31.x.x | 255.255.0.0 | /16 | 16 |
C | 192.168.0.x — 192.168.255.x | 255.255.255.0 | /24 | 256 |
![]() |
注意 |
---|---|
If one of these addresses is assigned to a host, then that host must not access the Internet directly but must access it through a gateway that acts as a proxy for individual services or else does Network Address Translation (NAT). The broadband router usually performs NAT for the consumer LAN environment. |
Although most hardware devices are supported by the Debian system, there are some network devices which require DFSG non-free firmware to support them. Please see 第 9.9.6 节 “Hardware drivers and firmware”.
Debian squeeze
and newer can manage the network
connection via management daemon software such
as NetworkManager (NM)
(network-manager and associated packages) or Wicd (wicd and associated packages).
They come with their own GUI and command-line programs as their user interfaces.
They come with their own daemon as their backend system.
They allow easy connection of your system to the Internet.
They allow easy management of wired and wireless network configuration.
They allow us to configure network independent of the legacy
ifupdown
package.
![]() |
注意 |
---|---|
Do not use these automatic network configuration tools for servers. These are aimed primarily for mobile desktop users on laptops. |
These modern network configuration tools need to be configured properly to
avoid conflicting with the legacy ifupdown
package and
its configuration file "/etc/network/interfaces
".
![]() |
提示 |
---|---|
Under systemd, the network may be configured
in |
![]() |
注意 |
---|---|
Some features of these automatic network configuration tools may suffer
regressions. These are not as robust as the legacy
|
Official documentations for NM and Wicd on Debian are provided in
"/usr/share/doc/network-manager/README.Debian
" and
"/usr/share/doc/wicd/README.Debian
", respectively.
Essentially, the network configuration for desktop is done as follows.
Make desktop user, e.g. foo
, belong to group
"netdev
" by the following (Alternatively, do it
automatically via D-bus under modern desktop
environments such as GNOME and KDE).
$ sudo adduser foo netdev
Keep configuration of "/etc/network/interfaces
" as simple
as in the following.
auto lo iface lo inet loopback
Restart NM or Wicd by the following.
$ sudo /etc/init.d/network-manager restart
$ sudo /etc/init.d/wicd restart
Configure your network via GUI.
![]() |
注意 |
---|---|
Only interfaces which are not listed in
" |
![]() |
提示 |
---|---|
If you wish to extend network configuration capabilities of NM, please seek
appropriate plug-in modules and supplemental packages such as
|
![]() |
小心 |
---|---|
These automatic network configuration tools may not be compatible with
esoteric configurations of legacy |
When the method described in 第 5.2 节 “The modern network configuration for desktop” does not suffice your needs, you should use the legacy network connection and configuration method which combines many simpler tools.
The legacy network connection is specific for each method (see 第 5.4 节 “The network connection method (legacy)”).
There are 2 types of programs for the low level network configuration on Linux (see 第 5.7.1 节 “Iproute2 commands”).
Old net-tools programs (ifconfig(8), …) are from the Linux NET-3 networking system. Most of these are obsolete now.
New Linux iproute2 programs (ip(8), …) are the current Linux networking system.
Although these low level networking programs are powerful, they are cumbersome to use. So high level network configuration systems have been created.
The ifupdown
package is the de facto standard for such
high level network configuration system on Debian. It enables you to bring
up network simply by doing , e.g., "ifup eth0
". Its
configuration file is the "/etc/network/interfaces
" file
and its typical contents are the following.
auto lo iface lo inet loopback auto eth0 iface eth0 inet dhcp
The resolvconf
package was created to supplement
ifupdown
system to support smooth reconfiguration of
network address resolution by automating rewrite of resolver configuration
file "/etc/resolv.conf
". Now, most Debian network
configuration packages are modified to use resolvconf
package (see "/usr/share/doc/resolvconf/README.Debian
").
Helper scripts to the ifupdown
package such as
ifplugd
, guessnet
,
ifscheme
, etc. are created to automate dynamic
configuration of network environment such as one for mobile PC on wired
LAN. These are relatively difficult to use but play well with existing
ifupdown
system.
These are explained in detail with examples (see 第 5.5 节 “The basic network configuration with ifupdown (legacy)” and 第 5.6 节 “The advanced network configuration with ifupdown (legacy)”).
![]() |
小心 |
---|---|
The connection test methods described in this section are meant for testing
purposes. It is not meant to be used directly for the daily network
connection. You are advised to use NM, Wicd, or the
|
The typical network connection method and connection path for a PC can be summarized as the following.
表 5.3. List of network connection methods and connection paths
PC | connection method | connection path |
---|---|---|
Serial port (ppp0 )
|
PPP | ⇔ modem ⇔ POTS ⇔ dial-up access point ⇔ ISP |
Ethernet port (eth0 )
|
PPPoE/DHCP/Static | ⇔ BB-modem ⇔ BB service ⇔ BB access point ⇔ ISP |
Ethernet port (eth0 )
|
DHCP/Static | ⇔ LAN ⇔ BB-router with network address translation (NAT) (⇔ BB-modem …) |
Here is the summary of configuration scripts for each connection method.
表 5.4. List of network connection configurations
connection method | configuration | backend package(s) |
---|---|---|
PPP | pppconfig to create deterministic chat
|
pppconfig , ppp |
PPP (alternative) | wvdialconf to create heuristic chat
|
ppp , wvdial |
PPPoE | pppoeconf to create deterministic chat
|
pppoeconf , ppp |
DHCP |
described in "/etc/dhcp/dhclient.conf "
|
isc-dhcp-client
|
static IP (IPv4) |
described in "/etc/network/interfaces "
|
iproute or net-tools (obsolete)
|
static IP (IPv6) |
described in "/etc/network/interfaces "
|
iproute
|
The network connection acronyms mean the following.
表 5.5. List of network connection acronyms
acronym | 說明 |
---|---|
POTS | plain old telephone service |
BB | broadband |
BB-service | e.g., the digital subscriber line (DSL), the cable TV, or the fiber to the premises (FTTP) |
BB-modem | e.g., the DSL modem, the cable modem, or the optical network terminal (ONT) |
LAN | local area network |
WAN | wide area network |
DHCP | dynamic host configuration protocol |
PPP | point-to-point protocol |
PPPoE | point-to-point protocol over Ethernet |
ISP | Internet service provider |
![]() |
注意 |
---|---|
The WAN connection services via cable TV are generally served by DHCP or PPPoE. The ones by ADSL and FTTP are generally served by PPPoE. You have to consult your ISP for exact configuration requirements of the WAN connection. |
![]() |
注意 |
---|---|
When BB-router is used to create home LAN environment, PCs on LAN are connected to the WAN via BB-router with network address translation (NAT). For such case, PC's network interfaces on the LAN are served by static IP or DHCP from the BB-router. BB-router must be configured to connect the WAN following the instruction by your ISP. |
The typical modern home and small business network, i.e. LAN, are connected to the WAN (Internet) using some consumer grade broadband router. The LAN behind this router is usually served by the dynamic host configuration protocol (DHCP) server running on the router.
Just install the isc-dhcp-client
package for the Ethernet
served by the dynamic host
configuration protocol (DHCP).
See dhclient.conf(5).
No special action is needed for the Ethernet served by the static IP.
The configuration script pppconfig
configures the PPP connection interactively just by selecting the
following.
The telephone number
The ISP user name
The ISP password
The port speed
The modem communication port
The authentication method
表 5.6. List of configuration files for the PPP connection with pppconfig
file | function |
---|---|
/etc/ppp/peers/<isp_name>
|
The pppconfig generated configuration file for
pppd specific to <isp_name>
|
/etc/chatscripts/<isp_name>
|
The pppconfig generated configuration file for
chat specific to <isp_name>
|
/etc/ppp/options
|
The general execution parameter for pppd
|
/etc/ppp/pap-secret
|
Authentication data for the PAP (security risk) |
/etc/ppp/chap-secret
|
Authentication data for the CHAP (more secure) |
![]() |
小心 |
---|---|
The "<isp_name>" value of " |
You can test configuration using low level network configuration tools as the following.
$ sudo pon <isp_name> ... $ sudo poff <isp_name>
See "/usr/share/doc/ppp/README.Debian.gz
".
A different approach to using
pppd(8)
is to run it from
wvdial(1)
which comes in the wvdial
package. Instead of
pppd
running
chat(8)
to dial in and negotiate the connection, wvdial
does the
dialing and initial negotiating and then starts pppd
to
do the rest.
The configuration script wvdialconf
configures the PPP
connection interactively just by selecting the following.
The telephone number
The ISP user name
The ISP password
wvdial
succeeds in making the connection in most cases
and maintains authentication data list automatically.
表 5.7. List of configuration files for the PPP connection with wvdialconf
file | function |
---|---|
/etc/ppp/peers/wvdial
|
The wvdialconf generated configuration file for
pppd specific to wvdial
|
/etc/wvdial.conf
|
The wvdialconf generated configuration file
|
/etc/ppp/options
|
The general execution parameter for pppd
|
/etc/ppp/pap-secret
|
Authentication data for the PAP (security risk) |
/etc/ppp/chap-secret
|
Authentication data for the CHAP (more secure) |
You can test configuration using low level network configuration tools as the following.
$ sudo wvdial ... $ sudo killall wvdial
See wvdial(1) and wvdial.conf(5).
When your ISP serves you with PPPoE connection and you decide to connect
your PC directly to the WAN, the network of your PC must be configured with
the PPPoE. The PPPoE stand for PPP over Ethernet. The configuration script
pppoeconf
configures the PPPoE connection interactively.
The configuration files are the following.
表 5.8. List of configuration files for the PPPoE connection with pppoeconf
file | function |
---|---|
/etc/ppp/peers/dsl-provider
|
The pppoeconf generated configuration file for
pppd specific to pppoe
|
/etc/ppp/options
|
The general execution parameter for pppd
|
/etc/ppp/pap-secret
|
Authentication data for the PAP (security risk) |
/etc/ppp/chap-secret
|
Authentication data for the CHAP (more secure) |
You can test configuration using low level network configuration tools as the following.
$ sudo /sbin/ifconfig eth0 up $ sudo pon dsl-provider ... $ sudo poff dsl-provider $ sudo /sbin/ifconfig eth0 down
See "/usr/share/doc/pppoeconf/README.Debian
".
The traditional TCP/IP network setup on
the Debian system uses ifupdown
package as a high level
tool. There are 2 typical cases.
For dynamic IP system such as mobile PCs,
you should setup TCP/IP network with the
resolvconf
package and enable you to switch your network
configuration easily (see 第 5.5.4 节 “The network interface served by the DHCP”).
For static IP system such as servers, you
should setup TCP/IP network without the
resolvconf
package and keep your system simple (see 第 5.5.5 节 “The network interface with the static IP”).
These traditional setup methods are quite useful if you wish to set up advanced configuration; find details in the following.
The ifupdown
package provides the standardized framework
for the high level network configuration in the Debian system. In this
section, we learn the basic network configuration with
ifupdown
with simplified introduction and many typical
examples.
The ifupdown
package contains 2 commands:
ifup(8)
and
ifdown(8).
They offer high level network configuration dictated by the configuration
file "/etc/network/interfaces".
表 5.9. List of basic network configuration commands with ifupdown
命令 | 操作 |
---|---|
ifup eth0
|
bring up a network interface eth0 with the configuration
eth0 if "iface eth0 " stanza exists
|
ifdown eth0
|
bring down a network interface eth0 with the
configuration eth0 if "iface eth0 "
stanza exists
|
![]() |
警告 |
---|---|
Do not use low level configuration tools such as ifconfig(8) and ip(8) commands to configure an interface in up state. |
![]() |
注意 |
---|---|
There is no command |
The key syntax of "/etc/network/interfaces
" as explained
in
interfaces(5)
can be summarized as the following.
表 5.10. List of stanzas in "/etc/network/interfaces
"
stanza | 說明 |
---|---|
"auto <interface_name> "
|
start interface <interface_name> upon start of the system |
"allow-auto <interface_name> "
|
同上 |
"allow-hotplug <interface_name> "
|
start interface <interface_name> when the kernel detects a hotplug event from the interface |
Lines started with "iface <config_name> … "
|
define the network configuration <config_name> |
Lines started with "mapping <interface_name_glob> "
|
define mapping value of <config_name> for the matching <interface_name> |
A line starting with a hash "# "
|
ignore as comments (end-of-line comments are not supported) |
A line ending with a backslash "\ "
|
extend the configuration to the next line |
Lines started with iface
stanza has the following
syntax.
iface <config_name> <address_family> <method_name> <option1> <value1> <option2> <value2> ...
For the basic configuration, the mapping
stanza is not used and
you use the network interface name as the network configuration name (See
第 5.6.5 节 “The mapping stanza”).
![]() |
警告 |
---|---|
Do not define duplicates of the " |
The following configuration entry in the
"/etc/network/interfaces
" file brings up the loopback
network interface lo
upon booting the system (via
auto
stanza).
auto lo iface lo inet loopback
This one always exists in the "/etc/network/interfaces
"
file.
After preparing the system by 第 5.4.1 节 “The DHCP connection with the Ethernet”, the network interface
served by the DHCP is configured by creating the configuration entry in the
"/etc/network/interfaces
" file as the following.
allow-hotplug eth0 iface eth0 inet dhcp
When the Linux kernel detects the physical interface
eth0
, the allow-hotplug
stanza causes
ifup
to bring up the interface and the iface
stanza causes
ifup
to use DHCP to configure the interface.
The network interface served by the static IP is configured by creating the
configuration entry in the "/etc/network/interfaces
" file
as the following.
allow-hotplug eth0 iface eth0 inet static address 192.168.11.100 netmask 255.255.255.0 gateway 192.168.11.1 dns-domain example.com dns-nameservers 192.168.11.1
When the Linux kernel detects the physical interface
eth0
, the allow-hotplug
stanza causes
ifup
to bring up the interface and the iface
stanza causes
ifup
to use the static IP to configure the interface.
Here, I assumed the following.
IP address range of the LAN network: 192.168.11.0
-
192.168.11.255
IP address of the gateway: 192.168.11.1
IP address of the PC: 192.168.11.100
The resolvconf
package: installed
The domain name: "example.com
"
IP address of the DNS server: 192.168.11.1
When the resolvconf
package is not installed, DNS related
configuration needs to be done manually by editing the
"/etc/resolv.conf
" as the following.
nameserver 192.168.11.1 domain example.com
![]() |
小心 |
---|---|
The IP addresses used in the above example are not meant to be copied literally. You have to adjust IP numbers to your actual network configuration. |
The wireless LAN (WLAN for short) provides the fast wireless connectivity through the spread-spectrum communication of unlicensed radio bands based on the set of standards called IEEE 802.11.
The WLAN interfaces are almost like normal Ethernet interfaces but require
some network ID and encryption key data to be provided when they are
initialized. Their high level network tools are exactly the same as that of
Ethernet interfaces except interface names are a bit different like
eth1
, wlan0
, ath0
,
wifi0
, … depending on the kernel drivers used.
![]() |
提示 |
---|---|
The |
Here are some keywords to remember for the WLAN.
表 5.11. List of acronyms for WLAN
acronym | full word | 說明 |
---|---|---|
NWID | Network ID | 16 bit network ID used by pre-802.11 WaveLAN network (very deprecated) |
(E)SSID | (Extended) Service Set Identifier | network name of the Wireless Access Points (APs) interconnected to form an integrated 802.11 wireless LAN, Domain ID |
WEP, (WEP2) | Wired Equivalent Privacy | 1st generation 64-bit (128-bit) wireless encryption standard with 40-bit key (deprecated) |
WPA | Wi-Fi Protected Access | 2nd generation wireless encryption standard (most of 802.11i), compatible with WEP |
WPA2 | Wi-Fi Protected Access 2 | 3rd generation wireless encryption standard (full 802.11i), non-compatible with WEP |
The actual choice of protocol is usually limited by the wireless router you deploy.
You need to install the wpasupplicant
package to support
the WLAN with the new WPA/WPA2.
In case of the DHCP served IP on WLAN
connection, the "/etc/network/interfaces
" file entry
should be as the following.
allow-hotplug ath0 iface ath0 inet dhcp wpa-ssid homezone # hexadecimal psk is encoded from a plaintext passphrase wpa-psk 000102030405060708090a0b0c0d0e0f101112131415161718191a1b1c1d1e1f
See "/usr/share/doc/wpasupplicant/README.modes.gz
".
You need to install the wireless-tools
package to support
the WLAN with the old WEP. (Your consumer grade router may still be using
this insecure infrastructure but this is better than nothing.)
![]() |
小心 |
---|---|
Please note that your network traffic on WLAN with WEP may be sniffed by others. |
In case of the DHCP served IP on WLAN
connection, the "/etc/network/interfaces
" file entry
should be as the following.
allow-hotplug eth0 iface eth0 inet dhcp wireless-essid Home wireless-key1 0123-4567-89ab-cdef wireless-key2 12345678 wireless-key3 s:password wireless-defaultkey 2 wireless-keymode open
See "/usr/share/doc/wireless-tools/README.Debian
".
You need to configure the PPP connection first as described before (see
第 5.4.3 节 “The PPP connection with pppconfig”). Then, add the
"/etc/network/interfaces
" file entry for the primary PPP
device ppp0
as the following.
iface ppp0 inet ppp provider <isp_name>
You need to configure the alternative PPP connection with
wvdial
first as described before (see 第 5.4.4 节 “The alternative PPP connection with wvdialconf”). Then, add the
"/etc/network/interfaces
" file entry for the primary PPP
device ppp0
as the following.
iface ppp0 inet wvdial
For PC connected directly to the WAN served by the PPPoE, you need to
configure system with the PPPoE connection as described before (see 第 5.4.5 节 “The PPPoE connection with pppoeconf”). Then, add the
"/etc/network/interfaces
" file entry for the primary
PPPoE device eth0
as the following.
allow-hotplug eth0 iface eth0 inet manual pre-up /sbin/ifconfig eth0 up up ifup ppp0=dsl down ifdown ppp0=dsl post-down /sbin/ifconfig eth0 down # The following is used internally only iface dsl inet ppp provider dsl-provider
The "/etc/network/run/ifstate
" file stores the intended network configuration states for all the
currently active network interfaces managed by the
ifupdown
package. Unfortunately, even if the
ifupdown
system fails to bring up the interface as
intended, the "/etc/network/run/ifstate
" file lists it
active.
Unless the output of the ifconfig(8) command for an interface does not have a line like following example, it can not be used as a part of IPV4 network.
inet addr:192.168.11.2 Bcast:192.168.11.255 Mask:255.255.255.0
![]() |
注意 |
---|---|
For the Ethernet device connected to the PPPoE, the output of the ifconfig(8) command lacks a line which looks like above example. |
When you try to reconfigure the interface, e.g. eth0
, you
must disable it first with the "sudo ifdown
eth0
" command. This removes the entry of
eth0
from the
"/etc/network/run/ifstate
" file. (This may result in some
error message if eth0
is not active or it is configured
improperly previously. So far, it seems to be safe to do this for the
simple single user work station at any time.)
You are now free to rewrite the "/etc/network/interfaces
"
contents as needed to reconfigure the network interface,
eth0
.
Then, you can reactivate eth0
with the "sudo ifup eth0
" command.
![]() |
提示 |
---|---|
You can (re)initialize the network interface simply by " |
The ifupdown-extra
package provides easy network
connection tests for use with the ifupdown
package.
The network-test(1) command can be used from the shell.
The automatic scripts are run for each ifup
command
execution.
The network-test
command frees you from the execution of
cumbersome low level commands to analyze the network problem.
The automatic scripts are installed in "/etc/network/*/
"
and perform the following.
Check the network cable connection
Check duplicate use of IP address
Setup system's static routes based on the
"/etc/network/routes
" definition
Check if network gateway is reachable
Record results in the "/var/log/syslog
" file
This syslog record is quite useful for administration of the network problem on the remote system.
![]() |
提示 |
---|---|
The automatic behavior of the |
The functionality of the ifupdown
package can be improved
beyond what was described in 第 5.5 节 “The basic network configuration with ifupdown (legacy)” with the
advanced knowledge.
The functionalities described here are completely optional. I, being lazy and minimalist, rarely bother to use these.
![]() |
小心 |
---|---|
If you could not set up network connection by information in 第 5.5 节 “The basic network configuration with ifupdown (legacy)”, you make situation worse by using information below. |
The ifplugd
package is an older automatic network
configuration tool which can manage only Ethernet connections. This solves
unplugged/replugged Ethernet cable issues for mobile PC etc. If you have
NetworkManager or Wicd (see 第 5.2 节 “The modern network configuration for desktop”) installed, you do
not need this package.
This package runs a daemon and replaces
auto or allow-hotplug functionalities (see 表 5.10 “List of stanzas in "/etc/network/interfaces
"”) and starts interfaces upon their
connection to the network.
Here is how to use the ifplugd
package for the internal
Ethernet port, e.g. eth0
.
Remove stanza in "/etc/network/interfaces
":
"auto eth0
" or "allow-hotplug eth0
".
Keep stanza in "/etc/network/interfaces
": "iface
eth0 inet …
" and "mapping …
".
Install the ifplugd
package.
Run "sudo dpkg-reconfigure ifplugd
".
Put eth0
as the "static interfaces to be watched by
ifplugd".
Now, the network reconfiguration works as you desire.
Upon power-on or upon hardware discovery, the interface is not brought up by itself.
Quick boot process without the long DHCP timeout.
No funny activated interface without proper IPv4 address (see 第 5.5.12 节 “The network configuration state of ifupdown”).
Upon finding the Ethernet cable, the interface is brought up.
Upon some time after unplugging the Ethernet cable, the interface is brought down automatically.
Upon plugging in another Ethernet cable, the interface is brought up under the new network environment.
![]() |
提示 |
---|---|
The arguments for the ifplugd(8) command can set its behaviors such as the delay for reconfiguring interfaces. |
The ifmetric
package enables us to manipulate metrics of
routes a posteriori even for DHCP.
The following sets the eth0
interface to be preferred
over the wlan0
interface.
Install the ifmetric
package.
Add an option line with "metric 0
" just below the
"iface eth0 inet dhcp
" line in
"/etc/network/interfaces
".
Add an option line with "metric 1
" just below the
"iface wlan0 inet dhcp
" line in
"/etc/network/interfaces
".
The metric 0 means the highest priority route and is the default one. The larger metric value means lower priority routes. The IP address of the active interface with the lowest metric value becomes the originating one. See ifmetric(8).
A single physical Ethernet interface can be configured as multiple virtual interfaces with different IP addresses. Usually the purpose is to connect an interface to several IP subnetworks. For example, IP address based virtual web hosting by a single network interface is one such application.
For example, let's suppose the following.
A single Ethernet interface on your host is connected to a Ethernet hub (not to the broadband router).
The Ethernet hub is connected to both the Internet and LAN network.
The LAN network uses subnet 192.168.0.x/24
.
Your host uses DHCP served IP address with the physical interface
eth0
for the Internet.
Your host uses 192.168.0.1
with the virtual interface
eth0:0
for the LAN.
The following stanzas in "/etc/network/interfaces
"
configure your network.
iface eth0 inet dhcp metric 0 iface eth0:0 inet static address 192.168.0.1 netmask 255.255.255.0 network 192.168.0.0 metric 1
![]() |
小心 |
---|---|
Although this configuration example with network address translation (NAT) using netfilter/iptables (see 第 5.9 节 “Netfilter infrastructure”) can provide cheap router for the LAN with only single interface, there is no real firewall capability with such set up. You should use 2 physical interfaces with NAT to secure the local network from the Internet. |
The ifupdown
package offers advanced network
configuration using the network
configuration name and the network
interface name. I use a terminology being slightly different
from the one used in
ifup(8)
and
interfaces(5).
表 5.12. List of terminology for network devices
manpage terminology | my terminology | examples in the following text | 說明 |
---|---|---|---|
physical interface name | network interface name | lo , eth0 ,
<interface_name> |
name given by the Linux kernel (using udev mechanism)
|
logical interface name | network configuration name | config1 , config2 ,
<config_name> |
name token following iface in the
"/etc/network/interfaces "
|
Basic network configuration commands in 第 5.5.1 节 “The command syntax simplified” require the network configuration name token of the iface
stanza to match the
network interface name in the
"/etc/network/interfaces
".
Advanced network configuration commands enables separation of the network configuration name and the network interface name in the
"/etc/network/interfaces
" as the following.
表 5.13. List of advanced network configuration commands with ifupdown
命令 | 操作 |
---|---|
ifup eth0=config1
|
bring up a network interface eth0 with the configuration
config1
|
ifdown eth0=config1
|
bring down a network interface eth0 with the
configuration config1
|
ifup eth0
|
bring up a network interface eth0 with the configuration
selected by mapping
stanza
|
ifdown eth0
|
bring down a network interface eth0 with the
configuration selected by mapping stanza
|
We skipped explaining the mapping
stanza in the
"/etc/network/interfaces
" in 第 5.5.2 节 “The basic syntax of "/etc/network/interfaces"” to avoid
complication. This stanza has the following syntax.
mapping <interface_name_glob> script <script_name> map <script_input1> map <script_input2> map ...
This provides advanced features to the
"/etc/network/interfaces
" file by automating the choice
of the configuration with the mapping script specified by
<script_name>
.
Let's follow the execution of the following.
$ sudo ifup eth0
When the "<interface_name_glob>
" matches
"eth0
", this execution produces the execution of the
following command to configure eth0
automatically.
$ sudo ifup eth0=$(echo -e '<script_input1> \n <script_input2> \n ...' | <script_name> eth0)
Here, script input lines with "map
" are optional and can
be repeated.
![]() |
注意 |
---|---|
The glob for |
Here is how to switch manually among several network configurations without
rewriting the "/etc/network/interfaces
" file as in 第 5.5.13 节 “The basic network reconfiguration” .
For all the network configuration you need to access, you create a separate
stanza in "/etc/network/interfaces
" file as the
following.
auto lo iface lo inet loopback iface config1 inet dhcp iface config2 inet static address 192.168.11.100 netmask 255.255.255.0 gateway 192.168.11.1 dns-domain example.com dns-nameservers 192.168.11.1 iface pppoe inet manual pre-up /sbin/ifconfig eth0 up up ifup ppp0=dsl down ifdown ppp0=dsl post-down /sbin/ifconfig eth0 down # The following is used internally only iface dsl inet ppp provider dsl-provider iface pots inet ppp provider provider
Please note the network configuration
name which is the token after iface
does not use the token for
the network interface name. Also, there
are no auto
stanza nor
allow-hotplug
stanza
to start the network interface eth0
automatically upon
events.
Now you are ready to switch the network configuration.
Let's move your PC to a LAN served by the DHCP. You bring up the network interface (the physical interface)
eth0
by assigning the network
configuration name (the logical interface name)
config1
to it by the following.
$ sudo ifup eth0=config1 Password: ...
The interface eth0
is up, configured by DHCP and
connected to LAN.
$ sudo ifdown eth0=config1 ...
The interface eth0
is down and disconnected from LAN.
Let's move your PC to a LAN served by the static IP. You bring up the
network interface eth0
by assigning the network configuration
name config2
to it by the following.
$ sudo ifup eth0=config2 ...
The interface eth0
is up, configured with static IP and
connected to LAN. The additional parameters given as
dns-*
configures "/etc/resolv.conf
"
contents. This "/etc/resolv.conf
" is better manged if
the resolvconf
package is installed.
$ sudo ifdown eth0=config2 ...
The interface eth0
is down and disconnected from LAN,
again.
Let's move your PC to a port on BB-modem connected to the PPPoE served
service. You bring up the network
interface eth0
by assigning the network configuration name pppoe
to it by the following.
$ sudo ifup eth0=pppoe ...
The interface eth0
is up, configured with PPPoE
connection directly to the ISP.
$ sudo ifdown eth0=pppoe ...
The interface eth0
is down and disconnected, again.
Let's move your PC to a location without LAN or BB-modem but with POTS and
modem. You bring up the network
interface ppp0
by assigning the network configuration name pots
to it by the following.
$ sudo ifup ppp0=pots ...
The interface ppp0
is up and connected to the Internet
with PPP.
$ sudo ifdown ppp0=pots ...
The interface ppp0
is down and disconnected from the
Internet.
You should check the "/etc/network/run/ifstate
" file for
the current network configuration state of the ifupdown
system.
![]() |
警告 |
---|---|
You may need to adjust numbers at the end of |
The ifupdown
system automatically runs scripts installed
in "/etc/network/*/
" while exporting environment
variables to scripts.
表 5.14. List of environment variables passed by the ifupdown system
environment variable | value passed |
---|---|
"$IFACE "
|
physical name (interface name) of the interface being processed |
"$LOGICAL "
|
logical name (configuration name) of the interface being processed |
"$ADDRFAM "
|
<address_family> of the interface |
"$METHOD "
|
<method_name> of the interface (e.g., "static") |
"$MODE "
|
"start" if run from ifup , "stop" if run from
ifdown
|
"$PHASE "
|
as per "$MODE ", but with finer granularity,
distinguishing the pre-up , post-up ,
pre-down and post-down phases
|
"$VERBOSITY "
|
indicates whether "--verbose " was used; set to 1 if so, 0
if not
|
"$PATH "
|
command search path:
"/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin "
|
"$IF_<OPTION> "
|
value for the corresponding option under the iface stanza
|
Here, each environment variable, "$IF_<OPTION>
", is
created from the name for the corresponding option such as <option1>
and <option2> by prepending "$IF_
", converting the
case to the upper case, replacing hyphens to underscores, and discarding
non-alphanumeric characters.
![]() |
提示 |
---|---|
See 第 5.5.2 节 “The basic syntax of "/etc/network/interfaces"” for <address_family>, <method_name>, <option1> and <option2>. |
The ifupdown-extra
package (see 第 5.5.14 节 “The ifupdown-extra package”) uses these environment variables to
extend the functionality of the ifupdown
package. The
ifmetric
package (see 第 5.6.2 节 “The ifmetric package”) installs the
"/etc/network/if-up.d/ifmetric
" script which sets the
metric via the "$IF_METRIC
" variable. The
guessnet
package (see 第 5.6.8 节 “Mapping with guessnet”), which provides simple and powerful
framework for the auto-selection of the network configuration via the
mapping mechanism, also uses these.
![]() |
注意 |
---|---|
For more specific examples of custom network configuration scripts using
these environment variables, you should check example scripts in
" |
Instead of manually choosing configuration as described in 第 5.6.6 节 “The manually switchable network configuration”, you can use the mapping mechanism described in 第 5.6.5 节 “The mapping stanza” to select network configuration automatically with custom scripts.
The
guessnet-ifupdown(8)
command provided by the guessnet
package is designed to
be used as a mapping script and provides powerful framework to enhance the
ifupdown
system.
You list test condition as the value for guessnet
options for each
network configuration under iface
stanza.
Mapping choses the iface
with first non-ERROR
result as the network configuration.
This dual usage of the "/etc/network/interfaces
" file by
the mapping script, guessnet-ifupdown
, and the original
network configuration infrastructure, ifupdown
, does not
cause negative impacts since guessnet
options only export
extra environment variables to scripts run by the
ifupdown
system. See details in
guessnet-ifupdown(8).
![]() |
注意 |
---|---|
When multiple |
Iproute2 commands offer complete low-level network configuration capabilities. Here is a translation table from obsolete net-tools commands to new iproute2 etc. commands.
表 5.15. Translation table from obsolete net-tools
commands to new
iproute2
commands
obsolete net-tools | new iproute2 etc. | manipulation |
---|---|---|
ifconfig(8) |
ip addr
|
protocol (IP or IPv6) address on a device |
route(8) |
ip route
|
routing table entry |
arp(8) |
ip neigh
|
ARP or NDISC cache entry |
ipmaddr
|
ip maddr
|
multicast address |
iptunnel
|
ip tunnel
|
tunnel over IP |
nameif(8) | ifrename(8) | name network interfaces based on MAC addresses |
mii-tool(8) | ethtool(8) | Ethernet device settings |
See ip(8) and IPROUTE2 Utility Suite Howto.
You may use low level network commands as follows safely since they do not change network configuration.
表 5.16. List of low level network commands
命令 | 說明 |
---|---|
ifconfig
|
display the link and address status of active interfaces |
ip addr show
|
display the link and address status of active interfaces |
route -n
|
display all the routing table in numerical addresses |
ip route show
|
display all the routing table in numerical addresses |
arp
|
display the current content of the ARP cache tables |
ip neigh
|
display the current content of the ARP cache tables |
plog
|
display ppp daemon log |
ping yahoo.com
|
check the Internet connection to "yahoo.com "
|
whois yahoo.com
|
check who registered "yahoo.com " in the domains database
|
traceroute yahoo.com
|
trace the Internet connection to "yahoo.com "
|
tracepath yahoo.com
|
trace the Internet connection to "yahoo.com "
|
mtr yahoo.com
|
trace the Internet connection to "yahoo.com " (repeatedly)
|
dig [@dns-server.com] example.com [{a|mx|any}]
|
check DNS records of
"example.com " by "dns-server.com " for
a "a ", "mx ", or
"any " record
|
iptables -L -n
|
check packet filter |
netstat -a
|
find all open ports |
netstat -l --inet
|
find listening ports |
netstat -ln --tcp
|
find listening TCP ports (numeric) |
dlint example.com
|
check DNS zone information of "example.com "
|
![]() |
提示 |
---|---|
Some of these low level network configuration tools reside in
" |
Generic network optimization is beyond the scope of this documentation. I touch only subjects pertinent to the consumer grade connection.
表 5.17. List of network optimization tools
軟件包 | 流行度 | 大小 | 說明 |
---|---|---|---|
iftop
|
V:10, I:109 | 93 | display bandwidth usage information on an network interface |
iperf
|
V:4, I:54 | 160 | Internet Protocol bandwidth measuring tool |
apt-spy
|
V:0, I:3 | 105 |
write a "/etc/apt/sources.list " file based on bandwidth
tests
|
ifstat
|
V:1, I:10 | 55 | InterFace STATistics Monitoring |
bmon
|
V:1, I:12 | 143 | portable bandwidth monitor and rate estimator |
ethstatus
|
V:0, I:3 | 39 | script that quickly measures network device throughput |
bing
|
V:0, I:2 | 62 | empirical stochastic bandwidth tester |
bwm-ng
|
V:2, I:17 | 88 | small and simple console-based bandwidth monitor |
ethstats
|
V:0, I:1 | 20 | console-based Ethernet statistics monitor |
ipfm
|
V:0, I:0 | 78 | bandwidth analysis tool |
The Maximum Transmission Unit
(MTU) value can be determined experimentally with
ping(8)
with "-M do
" option which sends ICMP packets with data
size starting from 1500 (with offset of 28 bytes for the IP+ICMP header) and
finding the largest size without IP fragmentation.
嘗試下列例子
$ ping -c 1 -s $((1500-28)) -M do www.debian.org PING www.debian.org (194.109.137.218) 1472(1500) bytes of data. From 192.168.11.2 icmp_seq=1 Frag needed and DF set (mtu = 1454) --- www.debian.org ping statistics --- 0 packets transmitted, 0 received, +1 errors
Try 1454 instead of 1500
You see ping(8) succeed with 1454.
This process is Path MTU (PMTU) discovery (RFC1191) and the tracepath(8) command can automate this.
![]() |
提示 |
---|---|
The above example with PMTU value of 1454 is for my previous FTTP provider which used Asynchronous Transfer Mode (ATM) as its backbone network and served its clients with the PPPoE. The actual PMTU value depends on your environment, e.g., 1500 for the my new FTTP provider. |
表 5.18. Basic guide lines of the optimal MTU value
network environment | MTU | rationale |
---|---|---|
Dial-up link (IP: PPP) | 576 | standard |
Ethernet link (IP: DHCP or fixed) | 1500 | standard and default |
Ethernet link (IP: PPPoE) | 1492 (=1500-8) | 2 bytes for PPP header and 6 bytes for PPPoE header |
Ethernet link (ISP's backbone: ATM, IP: DHCP or fixed) | 1462 (=48*31-18-8) | author's speculation: 18 bytes for Ethernet header, 8 bytes for SAR trailer |
Ethernet link (ISP's backbone: ATM, IP: PPPoE) | 1454 (=48*31-8-18-8) | see "Optimal MTU configuration for PPPoE ADSL Connections" for rationale |
In addtion to these basic guide lines, you should know the following.
Any use of tunneling methods (VPN etc.) may reduce optimal MTU further by their overheads.
The MTU value should not exceed the experimentally determined PMTU value.
The bigger MTU value is generally better when other limitations are met.
Here are examples for setting the MTU value from its default 1500 to 1454.
For the DHCP (see 第 5.5.4 节 “The network interface served by the DHCP”), you can replace
pertinent iface
stanza
lines in the "/etc/network/interfaces
" with the
following.
iface eth0 inet dhcp pre-up /sbin/ifconfig $IFACE mtu 1454
For the static IP (see 第 5.5.5 节 “The network interface with the static IP”), you can replace
pertinent iface
stanza
lines in the "/etc/network/interfaces
" with the
following.
iface eth0 inet static address 192.168.11.100 netmask 255.255.255.0 gateway 192.168.11.1 mtu 1454 dns-domain example.com dns-nameservers 192.168.11.1
For the direct PPPoE (see 第 5.4.5 节 “The PPPoE connection with pppoeconf”), you can replace pertinent
"mtu
" line in the
"/etc/ppp/peers/dsl-provider
" with the following.
mtu 1454
The maximum segment size (MSS) is used as an alternative measure of packet size. The relationship between MSS and MTU are the following.
MSS = MTU - 40 for IPv4
MSS = MTU - 60 for IPv6
![]() |
注意 |
---|---|
The iptables(8) (see 第 5.9 节 “Netfilter infrastructure”) based optimization can clamp packet size by the MSS and is useful for the router. See "TCPMSS" in iptables(8). |
The TCP throughput can be maximized by adjusting TCP buffer size parameters as described in "TCP Tuning Guide" and "TCP tuning" for the modern high-bandwidth and high-latency WAN. So far, the current Debian default settings serve well even for my LAN connected by the fast 1G bps FTTP service.
Netfilter provides infrastructure for stateful firewall and network address translation (NAT) with Linux kernel modules (see 第 3.3.1 节 “The kernel module initialization”).
表 5.19. List of firewall tools
軟件包 | 流行度 | 大小 | 說明 |
---|---|---|---|
iptables
|
V:243, I:993 | 1525 | administration tools for netfilter (iptables(8) for IPv4, ip6tables(8) for IPv6) |
arptables
|
V:0, I:2 | 124 | administration tools for netfilter (arptables(8) for ARP) |
ebtables
|
V:30, I:56 | 358 | administration tools for netfilter (ebtables(8) for Ethernet bridging) |
iptstate
|
V:0, I:4 | 115 | continuously monitor netfilter state (similar to top(1)) |
shorewall-init
|
V:0, I:0 | 78 | Shoreline Firewall initialization |
shorewall
|
V:6, I:16 | 2334 | Shoreline Firewall, netfilter configuration file generator |
shorewall-lite
|
V:0, I:0 | 84 | Shoreline Firewall, netfilter configuration file generator (light version) |
shorewall6
|
V:0, I:2 | 892 | Shoreline Firewall, netfilter configuration file generator (IPv6 version) |
shorewall6-lite
|
V:0, I:0 | 82 | Shoreline Firewall, netfilter configuration file generator (IPv6, light version) |
Main user space program of netfilter is iptables(8). You can manually configure netfilter interactively from shell, save its state with iptables-save(8), and restore it via init script with iptables-restore(8) upon system reboot.
Configuration helper scripts such as shorewall ease this process.
See documentations at http://www.netfilter.org/documentation/
(or in "/usr/share/doc/iptables/html/
").
![]() |
提示 |
---|---|
Although these were written for Linux 2.4, both iptables(8) command and netfilter kernel function apply for Linux 2.6 and 3.x kernel series. |