在 Ubuntu 上使用 ifupdown2
ifupdown2 改进了标准 Debian 和 Ubuntu 实例的网络配置，并且自 2.1 版本以来一直是 Cumulus Linux 的标准接口配置工具。本文介绍如何在 Ubuntu 主机上安装 ifupdown2。
验证 Ubuntu 版本
在开始安装之前，请验证实例上安装的 Ubuntu 版本
user@host:~$ cat /etc/lsb-release
DISTRIB_ID=Ubuntu
DISTRIB_RELEASE=14.04
DISTRIB_CODENAME=trusty
DISTRIB_DESCRIPTION="Ubuntu 14.04.3 LTS"
请按照以下适用于您安装的 Ubuntu 版本的说明进行操作。
在 Ubuntu 主机上安装 ifupdown2
Ubuntu 16.04 Xenial
Ubuntu 16.04 的默认软件包列表包含 ifupdown2。该软件包可在此处获得：ifupdown2。
在编辑器中打开
/etc/apt/sources.list。取消注释以下行，并保存文件
deb http://us.archive.ubuntu.com/ubuntu/ xenial universe更新 Ubuntu 实例
user@host:~$ sudo apt-get update安装
ifupdown2软件包user@host:~$ sudo apt-get install ifupdown2确保
systemd文件中存在以下配置[Unit] Description=ifupdown2 init script [Service] Type=oneshot ExecStart=/sbin/ifup -a ExecStop=/sbin/ifdown -a RemainAfterExit=yes [Install] WantedBy=multi-user.target
Ubuntu 14.04 Trusty
Ubuntu 14.04 的默认软件包列表不包含 ifupdown2。但是，由于 Ubuntu 16.04 包含它，您可以通过升级来解决此限制。
输入 root 帐户。以下说明中的其余命令假定使用 root 帐户。
将 Ubuntu Xenial 源添加到您的 Ubuntu Trusty 安装
root@host# echo "deb http://us.archive.ubuntu.com/ubuntu/ xenial universe" > /etc/apt/sources.list.d/xenial.list更新 Ubuntu 软件包缓存。您可能会在输出中看到警告，可以忽略这些警告
root@host# apt-get update <snip> Ign http://us.archive.ubuntu.com trusty/multiverse Translation-en_US Ign http://us.archive.ubuntu.com trusty/restricted Translation-en_US Ign http://us.archive.ubuntu.com trusty/universe Translation-en_US Reading package lists... Done W: Unknown Multi-Arch type 'no' for package 'libkf5akonadisearch-bin' W: Ignoring Provides line with DepCompareOp for package php-psr-http-message-implementation W: Ignoring Provides line with DepCompareOp for package php-psr-log-implementation W: Ignoring Provides line with DepCompareOp for package php-math-biginteger W: Unknown Multi-Arch type 'no' for package 'libkf5akonadisearch-bin' W: You may want to run apt-get update to correct these problems重要提示：在初始配置之后，存储库在安装软件包时具有相同的优先级，从而导致安装最新的 (Xenial) 软件包。由于本文的目标是仅安装
ifupdown2，因此此步骤确保您首先安装 Trusty 软件包。在继续之前，您必须提高 Trusty 存储库的优先级或降低 Xenial 存储库的优先级。以下示例步骤显示如何降低 Xenial 存储库的优先级，确保您首先安装 Trusty 软件包，并且仅在没有 Trusty 软件包时才安装 Xenial 软件包
创建一个名为
/etc/apt/preferences.d/xenial的文件，并将以下文本添加到该文件，然后保存该文件Explanation: give xenial a low priority number Package: * Pin: release a=xenial Pin-Priority: 100或者，运行此命令以执行相同的任务
root@host# echo -e "Explanation: give xenial a low priority number\nPackage: *\nPin: release a=xenial\nPin-Priority: 100\n" > /etc/apt/preferences.d/xenial验证 Xenial 软件包是否不覆盖所有其他软件包。以下示例使用 Ansible 软件包进行验证，因为 Trusty (Ansible 1.5.4) 和 Xenial (Ansible 1.9.4) 上提供了不同的版本
root@host# apt-cache policy ansible ansible: Installed: (none) Candidate: 1.5.4+dfsg-1 Version table: 1.9.4-1 0 100 http://us.archive.ubuntu.com/ubuntu/ xenial/universe amd64 Packages 1.7.2+dfsg-1~ubuntu14.04.1 0 100 http://us.archive.ubuntu.com/ubuntu/ trusty-backports/universe amd64 Packages 1.5.4+dfsg-1 0 500 http://us.archive.ubuntu.com/ubuntu/ trusty/universe amd64 Packages上面的
Candidate是 1.5.4，您将 Xenial 优先级从 500 降低到 100，这意味着 Xenial 软件包不覆盖 Trusty 存储库软件包。
安装
ifupdown2软件包依赖项root@host# apt-get install python-ipaddr python-argcomplete python-gvgen python-mako保持
ifupdown软件包root@host# echo ifupdown hold | dpkg --set-selections下载
ifupdown2 软件包：root@host# apt-get download ifupdown2手动安装
ifupdown2软件包root@host# dpkg --force-conflicts --force-depends --force-overwrite -i ./ifupdown2*.deb Selecting previously unselected package ifupdown2. dpkg: considering removing ifupdown in favour of ifupdown2 ... dpkg: warning: ignoring dependency problem with removal of ifupdown: upstart depends on ifupdown (>= 0.6.10ubuntu5) ifupdown is to be removed. Package ifupdown is on hold, not touching it. Use --force-hold to override. dpkg: regarding .../ifupdown2_1.0~git20151029-1_all.deb containing ifupdown2: ifupdown2 conflicts with ifupdown ifupdown (version 0.7.47.2ubuntu4.1) is present and installed. dpkg: warning: ignoring conflict, may proceed anyway! (Reading database ... 197912 files and directories currently installed.) Preparing to unpack .../ifupdown2_1.0~git20151029-1_all.deb ... Unpacking ifupdown2 (1.0~git20151029-1) ... Replacing files in old package ifupdown (0.7.47.2ubuntu4.1) ... dpkg: ifupdown2: dependency problems, but configuring anyway as you requested: ifupdown2 depends on init-system-helpers (>= 1.18~); however: Version of init-system-helpers on system is 1.14. Setting up ifupdown2 (1.0~git20151029-1) ... Installing new version of config file /etc/init.d/networking ... update-rc.d: warning: default start runlevel arguments (2 3 4 5) do not match networking Default-Start values (S) Processing triggers for man-db (2.6.7.1-1ubuntu1) ... Processing triggers for ureadahead (0.100.0-16) ... ureadahead will be reprofiled on next reboot检查已安装的
ifupdown2软件包中的“Depends”和“Conflicts”行。root@host# grep -A 34 "Package: ifupdown2" /var/lib/dpkg/status
Package: ifupdown2
Status: install ok installed
Priority: optional
Section: admin
Installed-Size: 595
Maintainer: Ubuntu Developers
Architecture: all
Version: 1.0~git20151029-1
Replaces: ifupdown
Provides: ifupdown
Depends: python:any (>= 2.7.5-5~), init-system-helpers (>= 1.18~), python-argcomplete, python-ipaddr
Suggests: python-gvgen, python-mako
Conflicts: ifupdown
Conffiles:
/etc/default/networking/networking.default 76a6935f125a8db5cbcddee1d422fc81
/etc/init.d/networking 703fab9e50c7c539efc6e1ce6b9c7633
/etc/network/ifupdown2/addons.conf c39be66aa58f59b4343c9dc6541043fe
/etc/network/ifupdown2/ifupdown2.conf 85fd2d75c77c6b68438a16888ae08510
Description: Network Interface Management tool similar to ifupdown
ifupdown2 is ifupdown re-written in Python. It replaces ifupdown and provides
the same user interface as ifupdown for network interface configuration.
Like ifupdown, ifupdown2 is a high level tool to configure (or, respectively
deconfigure) network interfaces based on interface definitions in
/etc/network/interfaces. It is capable of detecting network interface
dependencies and comes with several new features which are available as
new command options to ifup/ifdown/ifquery commands. It also comes with a new
command ifreload to reload interface configuration with minimum
disruption. Most commands are also capable of input and output in JSON format.
It is backward compatible with ifupdown /etc/network/interfaces format and
supports newer simplified format. It also supports interface templates with
python-mako for large scale interface deployments. See
/usr/share/doc/ifupdown2/README.rst for details about ifupdown2. Examples
are available under /usr/share/doc/ifupdown2/examples.
Original-Maintainer: Roopa Prabhu
Homepage: https://github.com/CumulusNetworks/ifupdown2可选：此时，您需要修改软件包管理器对
ifupdown2软件包的依赖项和冲突的理解。这需要在/var/lib/dpkg/status文件中进行两个非常精确的编辑。为了确保这些编辑产生期望的更改，首先确认您在步骤 11 中执行的两个查找和替换操作都只有一个实例要替换。root@host# grep -c "Conflicts: ifupdown" /var/lib/dpkg/status 1 root@host# grep -c "Depends: python:any (>= 2.7.5-5~), init-system-helpers (>= 1.18~), python-argcomplete, python-ipaddr" /var/lib/dpkg/status 1通过使用
sed命令查找和替换两行（在步骤 9 中以红色显示），使用新的依赖项和冲突信息更新软件包管理器以获取ifupdown2软件包root@host# sed -i "s/Depends: python:any (>= 2.7.5-5~), init-system-helpers (>= 1.18~), python-argcomplete, python-ipaddr/Depends: python:any (>= 2.7.5-5~), init-system-helpers (>= 1.14~), python-argcomplete, python-ipaddr/g" /var/lib/dpkg/status root@host# sed -i "/Conflicts: ifupdown/d" /var/lib/dpkg/status确认您已成功编辑文件。请注意，与步骤 9 相比，您已将最低要求的
init-system-helpers版本从 1.18 更改为 1.14，并且您删除了Conflicts行root@host# grep -A 34 "Package: ifupdown2" /var/lib/dpkg/status Package: ifupdown2 Status: install ok installed Priority: optional Section: admin Installed-Size: 595 Maintainer: Ubuntu Developers <ubuntu-devel-discuss@lists.ubuntu.com> Architecture: all Version: 1.0~git20151029-1 Replaces: ifupdown Provides: ifupdown Depends: python:any (>= 2.7.5-5~), init-system-helpers (>= 1.14~), python-argcomplete, python-ipaddr Suggests: python-gvgen, python-mako Conffiles: /etc/default/networking/networking.default 76a6935f125a8db5cbcddee1d422fc81 /etc/init.d/networking 703fab9e50c7c539efc6e1ce6b9c7633 /etc/network/ifupdown2/addons.conf c39be66aa58f59b4343c9dc6541043fe /etc/network/ifupdown2/ifupdown2.conf 85fd2d75c77c6b68438a16888ae08510 Description: Network Interface Management tool similar to ifupdown ifupdown2 is ifupdown re-written in Python. It replaces ifupdown and provides the same user interface as ifupdown for network interface configuration. Like ifupdown, ifupdown2 is a high level tool to configure (or, respectively deconfigure) network interfaces based on interface definitions in /etc/network/interfaces. It is capable of detecting network interface dependencies and comes with several new features which are available as new command options to ifup/ifdown/ifquery commands. It also comes with a new command ifreload to reload interface configuration with minimum disruption. Most commands are also capable of input and output in JSON format. It is backward compatible with ifupdown /etc/network/interfaces format and supports newer simplified format. It also supports interface templates with python-mako for large scale interface deployments. See /usr/share/doc/ifupdown2/README.rst for details about ifupdown2. Examples are available under /usr/share/doc/ifupdown2/examples. Original-Maintainer: Roopa Prabhu <roopa@cumulusnetworks.com> Homepage: https://github.com/CumulusNetworks/ifupdown2禁用 Xenial 软件包存储库，直到您再次需要它
root@host# sed -i "s/deb/#deb/g" /etc/apt/sources.list.d/xenial.list再次更新 Ubuntu 软件包缓存，以从软件包缓存中删除 Xenial 源。
root@host# apt-get update
验证 ifupdown2
ifupdown2 安装完成后，您可以使用 ifupdown2 特定的命令进行测试和验证
user@host:~$ sudo ifquery -ra
auto lo
iface lo inet loopback
mtu 65536
auto eth0
iface eth0
address 10.50.10.160/24
link-speed 1000
link-duplex full
link-autoneg on
安装其他工具
此外，您可以安装 brctl 和 bridge 命令，以便主机更像 Cumulus Linux。这些命令使您可以获取信息并配置您的网桥
user@host:~$ sudo apt-get install bridge-utils
您现在可以像在 Cumulus Linux 中一样查看主机上的网桥
user@host:~$ ifquery -a
auto lo
iface lo inet loopback
auto eth0
iface eth0 inet dhcp
auto bridge
iface bridge
bridge-ports eth1
bridge-stp on
使用 brctl 命令查看网桥 STP 状态
user@host:~$ brctl show
bridge name bridge id STP enabled interfaces
bridge 8000.080027d73d5d yes eth1
移除 ifupdown2
以正常的 Debian/Ubuntu 方式移除软件包
sudo apt-get remove ifupdown2仅在 Ubuntu 14.04 上:
sudo apt-get install ifupdown --reinstall