网络问题排查-整体思路

网络问题排查思路

网络模型

• 这是我们的网络知识框架
  

数据传输路径

• 这是知识框架中串联的线
  

排查问题路径-自下而上

链路层

1. 网线是否正常

]# ethtool ens33
Settings for ens33:
	Supported ports: [ TP ]
	Supported link modes:   10baseT/Half 10baseT/Full 
	                        100baseT/Half 100baseT/Full 
	                        1000baseT/Full 
	Supported pause frame use: No
	Supports auto-negotiation: Yes
	Supported FEC modes: Not reported
	Advertised link modes:  10baseT/Half 10baseT/Full 
	                        100baseT/Half 100baseT/Full 
	                        1000baseT/Full 
	Advertised pause frame use: No
	Advertised auto-negotiation: Yes
	Advertised FEC modes: Not reported
	Speed: 1000Mb/s
	Duplex: Full
	Port: Twisted Pair
	PHYAD: 0
	Transceiver: internal
	Auto-negotiation: on
	MDI-X: off (auto)
	Supports Wake-on: d
	Wake-on: d
	Current message level: 0x00000007 (7)
			       drv probe link
	Link detected: yes

2. 网卡状态

]# ip a s
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN group default qlen 1000
    link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
    inet 127.0.0.1/8 scope host lo
       valid_lft forever preferred_lft forever
    inet6 ::1/128 scope host 
       valid_lft forever preferred_lft forever
2: ens33: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP group default qlen 1000
    link/ether 00:0c:29:23:a7:0a brd ff:ff:ff:ff:ff:ff
    inet 192.168.74.130/24 brd 192.168.74.255 scope global secondary noprefixroute ens33
       valid_lft forever preferred_lft forever
    inet6 fe80::ae29:4ab5:ecb8:118d/64 scope link noprefixroute 
       valid_lft forever preferred_lft forever

网络层

1. IP|NETMASK|GATEWAY

]# vim /etc/sysconfig/network-scripts/ifcfg-ens33
TYPE=Ethernet
BOOTPROTO=static
NAME=ens33
UUID=bd385c8f-3c98-4afd-acc9-bc78f744bf16
DEVICE=ens33
ONBOOT=yes
IPADDR=192.168.74.130
NETMASK=255.255.255.0
GATEWAY=192.168.74.2

2. DNS
   1. /etc/resolve.conf
   2. nsloop
   3. dig
3. 路由
   1. ip route
   2. route

传输层

1. 服务端口
   1. ss
   2. netstat
   3. nmap
   4. telnet

应用层

1. 应用状态
   1. ps
   2. systemctl
   3. log日志

防火墙

1. iptables
2. firewall

本文只是简单介绍了下网络的排查思路和涉及到的命令，命令详细的解决请点击各自链接查看
有些链接尚未可用，因为还没整理处理....