ip addr和ifconfig在keepalived中Virtual IP address中的坑

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ip addr和ifconfig在keepalived中Virtual IP address中的坑

1、概述

今天遇到一个奇葩问题，给一个客户搭建haproxy+keepalived时，使用ifconfig看不到keepalived中配置的Virtual IP address，但是却可以ping通，日志也没有任何异常报错。尝试了多种方法之后已然无法解决。搭建实验环境测试，已然如此。

2、问题复现

[root@mydb ~]# ifconfig
ens160: flags=4163<UP,BROADCAST,RUNNING,MULTICAST>  mtu 1500
        inet 192.168.194.130  netmask 255.255.255.0  broadcast 192.168.194.255
        inet6 fe80::6413:8eda:1c3a:6da2  prefixlen 64  scopeid 0x20<link>
        ether 00:0c:29:e9:58:55  txqueuelen 1000  (Ethernet)
        RX packets 10561  bytes 8575255 (8.1 MiB)
        RX errors 0  dropped 0  overruns 0  frame 0
        TX packets 15344  bytes 978103 (955.1 KiB)
        TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0

lo: flags=73<UP,LOOPBACK,RUNNING>  mtu 65536
        inet 127.0.0.1  netmask 255.0.0.0
        inet6 ::1  prefixlen 128  scopeid 0x10<host>
        loop  txqueuelen 1000  (Local Loopback)
        RX packets 10239  bytes 908876 (887.5 KiB)
        RX errors 0  dropped 0  overruns 0  frame 0
        TX packets 10239  bytes 908876 (887.5 KiB)
        TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0

[root@mydb ~]# ping 192.168.194.50
PING 192.168.194.50 (192.168.194.50) 56(84) bytes of data.
64 bytes from 192.168.194.50: icmp_seq=1 ttl=64 time=0.033 ms
64 bytes from 192.168.194.50: icmp_seq=2 ttl=64 time=0.049 ms
64 bytes from 192.168.194.50: icmp_seq=3 ttl=64 time=0.071 ms
^C
--- 192.168.194.50 ping statistics ---
3 packets transmitted, 3 received, 0% packet loss, time 2043ms
rtt min/avg/max/mdev = 0.033/0.051/0.071/0.015 ms

3、无意找到VIP地址

我是比较喜欢使用ip a的，无意敲了一下，发现居然可以看到Virtual IP address，这也就解释了为啥可以ping通，实际已经生成了Virtual IP address。

[root@mydb ~]# ip a
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: ens160: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc mq state UP group default qlen 1000
    link/ether 00:0c:29:e9:58:55 brd ff:ff:ff:ff:ff:ff
    altname enp3s0
    inet 192.168.194.130/24 brd 192.168.194.255 scope global noprefixroute ens160
       valid_lft forever preferred_lft forever
    inet 192.168.194.50/24 scope global secondary ens160
       valid_lft forever preferred_lft forever
    inet6 fe80::6413:8eda:1c3a:6da2/64 scope link noprefixroute
       valid_lft forever preferred_lft forever

4、网络找原因

看了下这篇文章，写的也不是很清楚。仅查看

https://blog.csdn.net/kittygilr/article/details/79967000

5、查看命令帮助

[root@mydb ~]# ip address help
Usage: ip address {add|change|replace} IFADDR dev IFNAME [ LIFETIME ]
                                                      [ CONFFLAG-LIST ]
       ip address del IFADDR dev IFNAME [mngtmpaddr]
       ip address {save|flush} [ dev IFNAME ] [ scope SCOPE-ID ]
                            [ to PREFIX ] [ FLAG-LIST ] [ label LABEL ] [up]
       ip address [ show [ dev IFNAME ] [ scope SCOPE-ID ] [ master DEVICE ]
                         [ nomaster ]
                         [ type TYPE ] [ to PREFIX ] [ FLAG-LIST ]
                         [ label LABEL ] [up] [ vrf NAME ] ]
       ip address {showdump|restore}
IFADDR := PREFIX | ADDR peer PREFIX
          [ broadcast ADDR ] [ anycast ADDR ]
          [ label IFNAME ] [ scope SCOPE-ID ] [ metric METRIC ]
SCOPE-ID := [ host | link | global | NUMBER ]
FLAG-LIST := [ FLAG-LIST ] FLAG
FLAG  := [ permanent | dynamic | secondary | primary |
           [-]tentative | [-]deprecated | [-]dadfailed | temporary |
           CONFFLAG-LIST ]
CONFFLAG-LIST := [ CONFFLAG-LIST ] CONFFLAG
CONFFLAG  := [ home | nodad | mngtmpaddr | noprefixroute | autojoin ]
LIFETIME := [ valid_lft LFT ] [ preferred_lft LFT ]
LFT := forever | SECONDS
TYPE := { amt | bareudp | bond | bond_slave | bridge | bridge_slave |
          dsa | dummy | erspan | geneve | gre | gretap | gtp | ifb |
          ip6erspan | ip6gre | ip6gretap | ip6tnl |
          ipip | ipoib | ipvlan | ipvtap |
          macsec | macvlan | macvtap |
          netdevsim | nlmon | rmnet | sit | team | team_slave |
          vcan | veth | vlan | vrf | vti | vxcan | vxlan | wwan |
          xfrm | virt_wifi }

[root@mydb ~]# ifconfig --help
Usage:
  ifconfig [-a] [-v] [-s] <interface> [[<AF>] <address>]
  [add <address>[/<prefixlen>]]
  [del <address>[/<prefixlen>]]
  [[-]broadcast [<address>]]  [[-]pointopoint [<address>]]
  [netmask <address>]  [dstaddr <address>]  [tunnel <address>]
  [outfill <NN>] [keepalive <NN>]
  [hw <HW> <address>]  [mtu <NN>]
  [[-]trailers]  [[-]arp]  [[-]allmulti]
  [multicast]  [[-]promisc]
  [mem_start <NN>]  [io_addr <NN>]  [irq <NN>]  [media <type>]
  [txqueuelen <NN>]
  [[-]dynamic]
  [up|down] ...

  <HW>=Hardware Type.
  List of possible hardware types:
    loop (Local Loopback) slip (Serial Line IP) cslip (VJ Serial Line IP)
    slip6 (6-bit Serial Line IP) cslip6 (VJ 6-bit Serial Line IP) adaptive (Adaptive Serial Line IP)
    ash (Ash) ether (Ethernet) ax25 (AMPR AX.25)
    netrom (AMPR NET/ROM) rose (AMPR ROSE) tunnel (IPIP Tunnel)
    ppp (Point-to-Point Protocol) hdlc ((Cisco)-HDLC) lapb (LAPB)
    arcnet (ARCnet) dlci (Frame Relay DLCI) frad (Frame Relay Access Device)
    sit (IPv6-in-IPv4) fddi (Fiber Distributed Data Interface) hippi (HIPPI)
    irda (IrLAP) x25 (generic X.25) infiniband (InfiniBand)
    eui64 (Generic EUI-64)
  <AF>=Address family. Default: inet
  List of possible address families:
    unix (UNIX Domain) inet (DARPA Internet) inet6 (IPv6)
    ax25 (AMPR AX.25) netrom (AMPR NET/ROM) rose (AMPR ROSE)
    ipx (Novell IPX) ddp (Appletalk DDP) ash (Ash)
    x25 (CCITT X.25)
[root@mydb ~]#

这里主要的区别就是Type，ip a中有v，还是细节。

6、关键字

keepalvied安装成功，可以ping通vip（Virtual IP address），但无法找到vip（Virtual IP address）