Linux iproute2 命令家族（ip / ss）

胡高寒

2023-12-01

iproute 简介

iproute 与内核是密切相关的，所以两者版本是一致的。

[root@LeeMumu ~]# rpm -qi iproute
Name        : iproute
Version     : 4.11.0
Release     : 14.el7_6.2
Architecture: x86_64
Install Date: Sun 28 Jul 2019 09:28:29 AM EDT
Group       : Applications/System
Size        : 1793061
License     : GPLv2+ and Public Domain
Signature   : RSA/SHA256, Mon 29 Apr 2019 11:45:09 AM EDT, Key ID 24c6a8a7f4a80eb5
Source RPM  : iproute-4.11.0-14.el7_6.2.src.rpm
Build Date  : Wed 24 Apr 2019 10:03:34 AM EDT
Build Host  : x86-02.bsys.centos.org
Relocations : (not relocatable)
Packager    : CentOS BuildSystem <http://bugs.centos.org>
Vendor      : CentOS
URL         : http://kernel.org/pub/linux/utils/net/iproute2/
Summary     : Advanced IP routing and network device configuration tools
Description :
The iproute package contains networking utilities (ip and rtmon, for example)
which are designed to use the advanced networking capabilities of the Linux
kernel.
[root@LeeMumu ~]# uname -r
3.10.0-957.el7.x86_64
[root@LeeMumu ~]# cat /etc/redhat-release 
CentOS Linux release 7.6.1810 (Core)

ip 命令

用来显示或操纵Linux主机的路由、网络设备、策略路由和隧道，是Linux下较新的功能强大的网络配置工具。

show / manipulate routing, devices, policy routing and tunnels

语法格式：

# ip [ OPTIONS ] OBJECT { COMMAND | help }
				 OBJECT := { link | addr | route | netns  }

注意： OBJECT可简写，各OBJECT的子命令也可简写

1、ip link

ip link： network device configuration

1.1 up / down 和 multicast

ip  link  set - change device attributes
	dev NAME (default)            # 指明要管理的设备，dev 关键字可省略
	up 和 down                    # 对接口进行up或down
	multicast on 或 multicast off # 启用或禁用多播功能
	
# ip link set tangtang multicast on

1.2 name

# ip  link  set name NAME：重命名接口
	# 重命名接口时，需要对接口进行down，才能进行操作
	
# ip link set wlp2s0 name tangtang
RTNETLINK answers: Device or resource busy
# ip link set wlp2s0 down
# ip link set wlp2s0 name tangtang
# ip link show
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN mode DEFAULT 
	link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
2: enp1s0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP mode DEFAULT qlen 1000
	link/ether e4:3a:6e:0a:9b:88 brd ff:ff:ff:ff:ff:ff
3: tangtang: <BROADCAST,MULTICAST> mtu 1500 qdisc mq state DOWN mode DEFAULT qlen 1000
	link/ether d0:c5:d3:4e:25:71 brd ff:ff:ff:ff:ff:ff

1.3 mtu

# ip link set mtu NUMBER        # 设置 MTU 的大小，默认为1500

# ip link set tangtang mtu 1300

1.4 netns

netns PID           # ns为namespace，用于将接口移动到指定的网络名称空间

# ip netns add neo
# ip netns list
# ip link set tangtang netns neo

1.5 show

# ip  link  show  - display device attributes
	# 看二层设备的相关属性，和 IP 地址没关系

1.6 help

# ip  link  help -  显示简要使用帮助

2、ip netns

manage network namespaces

# ip netns list                # 列出所有的 netns
# ip netns add NAME            # 创建指定的 netns
# ip netns del NAME            # 删除指定的 netns
# ip netns exec NAME COMMAND   # 在指定的 netns 中运行命令

3、ip address

3.1 ip address add

ip address add - add new protocol address

# ip  addr  add  IFADDR  dev  IFACE
	[label NAME]：为额外添加的地址指明接口别名
		指定接口别名后，使用 ifconfig -a 可以查看到所有的接口名称和IP地址
		不指定接口别名后，使用 ip addr list IFACE 进行查看

	[broadcast ADDRESS]：广播地址；会根据IP和NETMASK自动计算得到
	
	[scope SCOPE_VALUE]：
		global：全局可用
		link：接口可用
		host：仅本机可用

# ip addr add 10.0.0.1/8 dev tangtang                                     
# ip addr add 10.0.0.2/8 dev tangtang                                     
# ip addr add 10.0.0.3/8 dev tangtang label tangtang:0                    
# ip addr add 192.168.0.2/24 dev tangtang label tangtang:1                
                                                                          
# ifconfig -a                                                             
tangtang: flags=4098<BROADCAST,MULTICAST>  mtu 1500                       
        inet 10.0.0.1  netmask 255.0.0.0  broadcast 0.0.0.0               
        ether d0:c5:d3:4e:25:71  txqueuelen 1000  (Ethernet)              
        RX packets 0  bytes 0 (0.0 B)                                     
        RX errors 0  dropped 0  overruns 0  frame 0                       
        TX packets 0  bytes 0 (0.0 B)                                     
        TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0        
                                                                          
tangtang:0: flags=4098<BROADCAST,MULTICAST>  mtu 1500                     
        inet 10.0.0.3  netmask 255.0.0.0  broadcast 0.0.0.0               
        ether d0:c5:d3:4e:25:71  txqueuelen 1000  (Ethernet)              
                                                                          
tangtang:1: flags=4098<BROADCAST,MULTICAST>  mtu 1500                     
        inet 192.168.0.2  netmask 255.255.255.0  broadcast 0.0.0.0        
        ether d0:c5:d3:4e:25:71  txqueuelen 1000  (Ethernet)              
                                                                          
# ip addr list tangtang                                                   
3: tangtang: <BROADCAST,MULTICAST> mtu 1500 qdisc mq state DOWN qlen 1000 
    link/ether d0:c5:d3:4e:25:71 brd ff:ff:ff:ff:ff:ff                    
    inet 10.0.0.1/8 scope global tangtang                                 
       valid_lft forever preferred_lft forever                            
    inet 192.168.0.2/24 scope global tangtang:1                           
       valid_lft forever preferred_lft forever                            
    inet 10.0.0.2/8 scope global secondary tangtang                       
       valid_lft forever preferred_lft forever                            
    inet 10.0.0.3/8 scope global secondary tangtang:0                     
       valid_lft forever preferred_lft forever

3.2 ip address delete

delete protocol address
# ip addr  delete  IFADDR  dev  IFACE

# ip addr delete 10.0.0.3/8 dev tangtang

3.3 ip link show

look at protocol addresses

# ip  addr   list  [IFACE]：显示接口的地址

# ip addr list tangtang                                                   
3: tangtang: <BROADCAST,MULTICAST> mtu 1500 qdisc mq state DOWN qlen 1000 
    link/ether d0:c5:d3:4e:25:71 brd ff:ff:ff:ff:ff:ff                    
    inet 10.0.0.1/8 scope global tangtang                                 
       valid_lft forever preferred_lft forever                            
    inet 192.168.0.2/24 scope global tangtang:1                           
       valid_lft forever preferred_lft forever                            
    inet 10.0.0.2/8 scope global secondary tangtang                       
       valid_lft forever preferred_lft forever

3.4 ip link flush

flush protocol addresses
# ip  addr  flush  dev  IFACE  清楚接口所有地址

# ip addr flush dev tangtang

4、ip route

routing table management

# ip route add - add new route
# ip route change - change route
# ip route replace - change or add new one
	# ip  route   add  TYPE PREFIX  via GW  [dev  IFACE]  [src SOURCE_IP]
		IFACE 有多个地址，在配置路由时，可以指定 SOURCE_IP 
		GW 下一跳

# ip route delete - delete route
	ip  route  del  TYPE PRIFIX 

# ip route show - list routes
	TYPE PRIFIX  
# ip route flush - flush routing tables  # 清除路由/指定路由
	TYPE  PRIFIX

# ip route get - get a single route      # 获取到达特定目的地址的路由条目
	ip  route  get  TYPE PRIFIX

# ip route add 192.168.0.0/24 via 10.0.0.1 dev eth1 src 10.0.20.100
	## 配置带源地址的路由

# ip route add 192.168.10.0/24 via 192.168.5.100 dev eth0
	## 前往目的网络 192.168.10.0/24 的下一跳是 192.168.5.100 ，接口是 eth0
	
# ip route add default via GW
# ip route delete 192.168.1.0/24
# ip route get 192.168.0.0/24

# ip route get 192.168.1.0/24
broadcast 192.168.1.0 dev ens33 src 192.168.1.9 
    cache <local,brd> 

# ip route add default via 192.168.1.2 dev eth0
	## 默认路由指向 192.168.1.2 ，接口是 eth0
	## 只要一个默认路由就 OK

[root@Tang-1 ~]# ip route show
default via 172.16.141.1 dev enp1s0 proto static metric 100 
172.16.141.0/24 dev enp1s0 proto kernel scope link src 172.16.141.209 metric 100 
[root@Tang-1 ~]# ip route list
default via 172.16.141.1 dev enp1s0 proto static metric 100 
172.16.141.0/24 dev enp1s0 proto kernel scope link src 172.16.141.209 metric 100 
[root@Tang-1 ~]# route -n
Kernel IP routing table
Destination     Gateway         Genmask         Flags Metric Ref    Use Iface
0.0.0.0         172.16.141.1    0.0.0.0         UG    100    0        0 enp1s0
172.16.141.0    0.0.0.0         255.255.255.0   U     100    0        0 enp1s0

5、ip link set

# ip link set eth0 up
	## 启动 eth0 

# ip link set eth0 down
	## 关闭 eth0

# ip link set eth0 mtu 1000
	## 更改 MTU 的值为 1000 bytes.使用 ifconfig 也能更新网卡的 MTU

# ip link set eth0 name vbird
    SIOCSIFNAME: Device or resource busy
	## 该设备目前是启动，应该先

# ip link set eth0 down     mtu 900 qdisc pfifo_fast qlen 1000
    link/ehter 00:40:d0:13:c3:46 brd ff:ff:ff:ff:ff:ff
	## 网卡名称也可以进行改变，ifcfg-eth0 建议使用默认的接口名称

# ip link set vbird name eth0 
	## 设备的硬件相关信息，包括MTU、MAC及传输的模式等，都能在这里设置
	## address的项目后接的可是 MAC 而不是IP

ss 命令

iproute2 包附带的一个工具，用来显示处于活动状态的套接字信息。ss命令可以用来获取socket统计信息，它可以显示和netstat类似的内容。但ss的优势在于它能够显示更多更详细的有关TCP和连接状态的信息，而且比netstat更快速更高效。

1、ss 语法格式

another utility to investigate sockets

ss  [options]  [ FILTER ]     
	OPTIONS：                        
		-t：TCP协议的相关连接       
		-u：UDP相关的连接           
		-w：raw socket相关的连接    
		-l：监听状态的连接          
		-a：所有状态的连接          
		-n：数字格式                
		-p：相关的程序及其PID       
		-e：扩展格式信息            
		-m：内存用量                
		-o：计时器信息              
	
	FILTER := [ state TCP-STATE ]  [ EXPRESSION ]
		实现状态过滤的功能

	EXPRESSION：
		dport = 
		sport = 
			示例：'( dport = :22 or sport = :22)'

# ss  -tan  '(  dport = :22  or sport = :22  )'   注意空格
# ss  -tan  state  ESTABLISHED  只显示已连接状态的连接

[root@LeeMumu ~]# ss -tanp                                                                              
State      Recv-Q Send-Q   Local Address:Port   Peer Address:Port                                       
LISTEN     0      128                  *:22                *:*        users:(("sshd",pid=7017,fd=3))    
LISTEN     0      100          127.0.0.1:25                *:*        users:(("master",pid=7148,fd=13)) 
ESTAB      0      52         192.168.1.9:22    192.168.1.199:64402    users:(("sshd",pid=7282,fd=3))    
LISTEN     0      128                 :::22               :::*        users:(("sshd",pid=7017,fd=4))    
LISTEN     0      100                ::1:25               :::*        users:(("master",pid=7148,fd=14)) 
[root@LeeMumu ~]# ss -tan                                                                               
State      Recv-Q Send-Q   Local Address:Port   Peer Address:Port                                       
LISTEN     0      128                  *:22                *:*                                          
LISTEN     0      100          127.0.0.1:25                *:*                                          
ESTAB      0      52         192.168.1.9:22    192.168.1.199:64402                                      
LISTEN     0      128                 :::22               :::*                                          
LISTEN     0      100                ::1:25               :::*

2、TCP 常见状态

TCP FSM：
	LISTEN         # 监听
	ESTABLISEHD    # 建立的连接
	FIN_WAIT_1     # 等待断开连接
	FIN_WAIT_2     # 确认断开连接
	SYN_SENT       # 发送
	SYN_RECV       # 接收
	CLOSED         # 关闭

[root@LeeMumu ~]# ss  -tan  '(  dport = :22  or sport = :22  )'
State      Recv-Q Send-Q        Local Address:Port             Peer Address:Port        
LISTEN     0      128                       *:22                          *:*               
ESTAB      0      52              192.168.1.9:22              192.168.1.199:64402           
LISTEN     0      128                      :::22                         :::*