NIC alias

• 一つの物理NICに複数のIPを割り当てる

CentOS

• ​Tips Collection - Red Hat Linux

設定

• /etc/sysconfig/network-scripts/
  • ifcfg-eth?:? を作る
  • 書式は通常の ifcfg-eth? と同じ
  • 例
    • dhcp (後述)

      DEVICE=eth0:0
      BOOTPROTO=dhcp
      ONBOOT=yes
      DHCP_HOSTNAME=centos5-test
      

    • static

      DEVICE=eth0:0
      BOOTPROTO=static
      IPADDR=192.168.40.250
      NETMASK=255.255.255.0
      GATEWAY=192.168.40.2
      ONBOOT=yes
      DHCP_HOSTNAME=centos5-test
      

• ifconfig (static)

  eth0      Link encap:Ethernet  HWaddr 00:0C:29:XX:XX:XX
            inet addr:192.168.40.141  Bcast:192.168.40.255  Mask:255.255.255.0
            UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
            RX packets:102642 errors:0 dropped:0 overruns:0 frame:0
            TX packets:1738 errors:0 dropped:0 overruns:0 carrier:0
            collisions:0 txqueuelen:1000
            RX bytes:11384683 (10.8 MiB)  TX bytes:234313 (228.8 KiB)
            Interrupt:59 Base address:0x2000
  
  eth0:0    Link encap:Ethernet  HWaddr 00:0C:29:XX:XX:XX
            inet addr:192.168.40.250  Bcast:192.168.40.255  Mask:255.255.255.0
            UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
            Interrupt:59 Base address:0x2000
  

dhcpについて

• 以下の問題は、BOOTPROTO=static の際には発生しない模様

• ifup eth0:0 でエラーが出る

  Determining IP information for eth0:0...SIOCSIFFLAGS: Cannot assign requested address
  SIOCSIFFLAGS: Cannot assign requested address
   done.
  

• IP自体は正常にassignされる
  • ifconfig

    eth0      Link encap:Ethernet  HWaddr 00:0C:29:XX:XX:XX
              inet addr:192.168.40.141  Bcast:192.168.40.255  Mask:255.255.255.0
              UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
              RX packets:102862 errors:0 dropped:0 overruns:0 frame:0
              TX packets:1939 errors:0 dropped:0 overruns:0 carrier:0
              collisions:0 txqueuelen:1000
              RX bytes:11403063 (10.8 MiB)  TX bytes:260163 (254.0 KiB)
              Interrupt:59 Base address:0x2000
    
    eth0:0    Link encap:Ethernet  HWaddr 00:0C:29:XX:XX:XX
              inet addr:192.168.40.142  Bcast:192.168.40.255  Mask:255.255.255.0
              UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
              Interrupt:59 Base address:0x2000
    

• boot時のエラー
  • attachment:centos-alias.png​
• IPもassignされず
  • fconfig eth0:0

    eth0:0    Link encap:Ethernet  HWaddr 00:0C:29:XX:XX:XX
              UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
              Interrupt:59 Base address:0x2000
    

• ifup eth0:0

  Determining IP information for eth0:0...SIOCSIFFLAGS: Cannot assign requested address
  SIOCSIFFLAGS: Cannot assign requested address
  SIOCGIFADDR: Cannot assign requested address
  SIOCSIFBROADCAST: Cannot assign requested address
  SIOCSIFBRDADDR: Cannot assign requested address
  SIOCSIFFLAGS: Cannot assign requested address
   done.
  

  • assignされず
• ifup eth0:0

  Determining IP information for eth0:0...SIOCSIFFLAGS: Cannot assign requested address
  SIOCSIFFLAGS: Cannot assign requested address
  SIOCSIFFLAGS: Cannot assign requested address
  SIOCSIFFLAGS: Cannot assign requested address
  SIOCSIFFLAGS: Cannot assign requested address
  SIOCSIFFLAGS: Cannot assign requested address
   done.
  

  • assignされた
    • ifconfig eth0:0

      eth0:0    Link encap:Ethernet  HWaddr 00:0C:29:XX:XX:XX
                inet addr:192.168.40.141  Bcast:192.168.40.255  Mask:255.255.255.0
                UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
                Interrupt:59 Base address:0x2000
      

• assignされたりされなかったりするため、不安定