Configure Virtualbox Network devices for RAC and Internet Access

 

VirtualBox configuration using RAC setup and Internet access


Network Device  Configuration : 
Virtual  Clients  : OEL 6.x Virtualbox  
  eth0  -> Bridged Network  : inet addr:192.168.1.XXX  Bcast:10.0.2.255     [ Internet Access ]
  eth1  -> Internal Network : inet addr:192.168.5.101  Bcast:192.168.5.255  [ Public RAC Interface ]
  eth2  -> Internal Network : inet addr:192.168.2.101  Bcast:192.168.5.255  [ Private RAC Interface ]
  eth3  -> Internal Network : inet addr:192.168.3.101  Bcast:192.168.5.255  [ Private RAC Interface ]

Virtualbox host : Windows 7 using LTE router connection 
  Ethernet-Adapter LAN-Verbindung:
   Verbindungsspezifisches DNS-Suffix: speedport.ip
   Beschreibung. . . . . . . . . . . : Realtek PCIe GBE Family Controller
   Physikalische Adresse . . . . . . : D4-3D-7E-99-B8-2D
   DHCP aktiviert. . . . . . . . . . : Ja
   Autokonfiguration aktiviert . . . : Ja
   Verbindungslokale IPv6-Adresse  . : fe80::c52f:f681:bb0b:c358%11(Bevorzugt)
   IPv4-Adresse  . . . . . . . . . . : 192.168.1.2(Bevorzugt)
   Subnetzmaske  . . . . . . . . . . : 255.255.255.0
   Lease erhalten. . . . . . . . . . : Samstag, 10. Januar 2015 01:48:03
   Lease läuft ab. . . . . . . . . . : Sonntag, 11. Januar 2015 01:48:02
   Standardgateway . . . . . . . . . : 192.168.1.1
   DHCP-Server . . . . . . . . . . . : 192.168.1.1
   DHCPv6-IAID . . . . . . . . . . . : 248790398
   DHCPv6-Client-DUID. . . . . . . . : 00-01-00-01-19-4F-39-F9-D4-3D-7E-99-B8-2D
   DNS-Server  . . . . . . . . . . . : 192.168.1.1
                                       192.168.1.1
   NetBIOS über TCP/IP . . . . . . . : Aktiviert

Requirements  for our planned DNS setup
 - All VirtualBox clients should be able to connect to the Internet ( simplifes yum updates , ... ) and RAC GNS
 - Our RAC DNS is running on 192.168.5.50 the RAC GNS is runnuing on 192.168.5.54 
 - eth0 should not modify /etc/resolv.conf by dhclient ( dhclient is used as eth0 in configured as a brigded device )
 - eth0 should pick up its DHCP address from the LTE router ( DNS 192.168.1.1 ) 
 - Double check that all Virtulbox devices has its cable connected - it will save a lot of time !
 - As we don't want that dhclient ( used for eth0 ) overwrites our /etc/resolv.conf we need to set 
   PEERDNS=no in ifcfg-eth0 in any configured node.
  
Required Linux Network Devices Configuration  
[root@grac41 network-scripts]# cat ifcfg-eth0
TYPE=Ethernet
BOOTPROTO=dhcp
DEFROUTE=yes
IPV4_FAILURE_FATAL=yes
IPV6INIT=no
NAME=eth0
ONBOOT=yes
DNS1=192.168.5.50
DOMAIN="example.com grid4.example.com de.oracle.com"
HWADDR=08:00:27:82:47:3F
PEERDNS=no
PEERROUTES=yes

 -   PEERDNS=<answer>, where <answer> is one of the following:
        yes — Modify /etc/resolv.conf with information from the server. If using DHCP, then yes is the default.
        no — Do not modify /etc/resolv.conf.
 -   Pitfall: Don't expect that adding DNS2=192.168.1.1 would help to get the LET router queried. I won't.
              At least as long DNS1 is up an running . So we need to setup BIND zone delegation !    

Network device: eth1 ( similar for eth2 and eht3 )  
TYPE=Ethernet
BOOTPROTO=none
DEFROUTE=yes
IPV4_FAILURE_FATAL=yes
IPV6INIT=no
NAME=eth1
UUID=4f9f8f33-825e-407c-b047-7f6670f7c24e
ONBOOT=yes
IPADDR=192.168.5.101
PREFIX=24
HWADDR=08:00:27:8D:8A:93
LAST_CONNECT=1380099042

Restart network and verify setup :
[root@ns1 named]# service network restart
[root@ns1 named]# ifconfig 
eth0      Link encap:Ethernet  HWaddr 08:00:27:E6:71:54  
          inet addr:192.168.1.6  Bcast:192.168.1.255  Mask:255.255.255.0

eth1      Link encap:Ethernet  HWaddr 08:00:27:8D:8A:93  
          inet addr:192.168.5.101  Bcast:192.168.5.255  Mask:255.255.255.0

eth2      Link encap:Ethernet  HWaddr 08:00:27:6B:E2:BD  
          inet addr:192.168.2.101  Bcast:192.168.2.255  Mask:255.255.255.0

eth3      Link encap:Ethernet  HWaddr 08:00:27:09:F0:99  
          inet addr:192.168.3.101  Bcast:192.168.3.255  Mask:255.255.255.0

--> Setup worked getting a DHCP address for eth0 [ 192.168.1.6 ] and fixed for eth1,eth2,eth3 [ 192.168.5.101 ]

Always verify   /etc/resolv.conf - should be configured by  NetworkManager with the Nameserver we have defined :  
[root@grac41 ~]# cat /etc/resolv.conf
# Generated by NetworkManager
search example.com grid4.example.com de.oracle.com
nameserver 192.168.5.50

Note - Double check configuration for eth0 :
If you get a different  /etc/resolv.conf file after a server reboot  with an add. line 
representing your Router address like : 
   nameserver 192.168.1.1  --> this is my  LTE router address !! 
verify your Network devices and change Methode for eth0  to: Automatic (DHCP) address  only  

System -> Preferences -> Network connections --> eth0 --> IPv4 Settings --> Methode
   Automatic (DHCP) addresses only

Use the GUI and double check that eth0 is configrure with Automatic (DHCP) address only: 
rac_net_dev

 

Potential Errors

Bringing up interface eth1:  
Error: Connection activation failed: Device not managed by NetworkManager or unavailable

Solution: 
1) Check whether you have connected the  cable in Virtualbox -> Devices -> Network -> Adapter  
2) Always check Virtual box NETWORK Adapters and Linux network devices are in SYNC ! 
   -> Adapter 1 MAC address [ 080027813C6E ]  is identical with HWADDR in ifcfg-eth0  [ 08:00:27:81:3C:6E ] 
      Adapter 2 MAC address [ 0800274425B9 ]  is identical with HWADDR in ifcfg-eth1  [ 08:00:27:44:25:B9 ]
      Adapter 3 MAC address [ 0800274C8E07 ]  is identical with HWADDR in ifcfg-eth2  [ 08:00:27:4C:8E:07 ] 
      ...   
Note you can easily end up that your network is not working if  you change HWADDR/MAC 
address in ifcfg-ethX manually.

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