Network Service down

Issue

• We got service down alert. After we restarted network service was o.k.

• the following alert message was informed at 22:16 by DBA-side.

  ORA-03114: not connected to ORACLE
  

• This server uses only eth0 and i could not confirm the any trouble of network interface. before restart network service, i checked the following.

  # netstat -r
  
  Kernel IP routing table
  
  Destination     Gateway         Genmask         Flags   MSS Window  irtt Iface
  172.19.112.0    *               255.255.255.0   U         0 0          0 eth0
  169.254.0.0     *               255.255.0.0     U         0 0          0 eth0
  

• To resolve this issue(not getting the default gateway), i restarted the network service.

  # netstat -r
  Kernel IP routing table
  Destination     Gateway         Genmask         Flags   MSS Window  irtt Iface
  172.19.112.0    *               255.255.255.0   U         0 0          0 eth0
  169.254.0.0     *               255.255.0.0     U         0 0          0 eth0
  default         172.19.112.1    0.0.0.0         UG        0 0          0 eth0