Creating Oracle EBS R12 MultiNode Lab With iSCSI Shared Storage - Part I

I would be sharing the steps for creating your multinode Oracle Apps R12 Lab in 2 parts, Because of its length. Also, will stop the DB node with its default 10G database in this particular post. This post was drafted long back, but never published, which I am doing now. Hopefully, this helps you creating your dream machine.

I created my lab using these steps, the screenshots are values in some places may seem to be irrelavant, But you need to identify the corrections needed as you follow the steps, Because I gathered these informations from various blogs and documents in bits and pieces and tailored into one, So that, I could finish the job in one go!!

Note:- This "job in 1 go" means 2 weeks of continuous work, and for shared storage setup alone, I had to spent almost 48 Hrs continously, Since, I was never having knowledge beyond Oracle Apps/ Oracle Database software installation and managing it. The most challenging part for me in this whole episode was shared storage setup using Openfiler and this was about 2 years ago from now. After this excercise, I got the idea on how iSCSI storage is setup for large infrastructures. 

1) Hardware configuration

      

1.1 Desktops – (DELL Optiplex 755) – 5 No’s

2) Install Linux OS and required (For DB nodes)

2.1 Disk Partitioning Setup

2.2 Partitioning

2.3 Boot Loader Configuration

2.4 Network Configuration

2.5 Package Installation Defaults

2.6 Firewall

2.7 Create User

2.8 Perform the same installation on the second node

3) Install Linux RPM’s for Oracle RAC)

3.1 64-bit (x86_64) Installations

4) Network Configuration

4.1 Introduction to Network Settings

4.2 Configuring Public and Private Network

4.3 About Virtual IP

4.4 Confirm the RAC Node Name is Not Listed in Loopback Address

4.5 Confirm localhost is defined in the /etc/hosts file for the loopback address

4.6 Adjusting Network Settings

4.7 Check and turn off UDP ICMP rejections:

5) Openfiler – NAS/SAN Appliance Download/Install

5.1 Install Openfiler

5.2 Boot Screen

5.3 Media Test

5.4 Welcome to Openfiler NSA

5.5 Keyboard Configuration

5.6 Disk Partitioning Setup

5.7 Automatic Partitioning

5.8 Partitioning

5.9 Network Configuration

5.10 Modify /etc/hosts File on Openfiler Server

5.11 Configure iSCSI Volumes using Openfiler

5.12 Services

5.13 Network Access Configuration

5.14 Physical Storage

5.15 Partitioning the Physical Disk

5.16 Volume Group Management

5.17 Logical Volumes

5.18 iSCSI Targets

5.19 Create New Target IQN

5.20 LUN Mapping

5.21 Network ACL

5.22 Configure iSCSI Volumes on Oracle RAC Nodes

5.23 Installing the iSCSI (initiator) service

5.24 Configure the iSCSI (initiator) service

5.25 Manually Log In to iSCSI Targets

5.26 Configure Automatic Log In

5.27 Create Persistent Local SCSI Device Names

5.28 Create Partitions on iSCSI Volumes

5.29 Verify New Partitions

6) Shared Storage & Interfaces Setup done for DB RAC Conversion

7) R12 Installation paths

7.1 R12 Installation (Initially 2 mid-tier & 1 DB-tier node)

8) R12 DB-Tier RAC Conversion

8.1 Check the hardware setup done previously

8.2 CRS Installation

8.3 Install Oracle DB 10.2.0.1 Binaries

8.4 Install Oracle DB Components from Components CD

8.5 Upgrade CRS & Database software to 10.2.0.2

8.6 Upgrade the apps database to 10.2.0.2 (utlu102i.sql)

8.7 Listener Configuration

8.8 Create ASM Instance and ASM Diskgroups

8.9 Run DBCA to configure ASM instances

8.10 Prepare ConvertToRAC.xml using rconfig

8.11 Create a new spfile on ASM for target(RAC) DB_Home

8.12 RUN rconfig

8.13 Enable Autoconfig on database tier

8.14 Run Autoconfig on database tier node-1 & node-2

8.15 Check database & nodeapps status using srvctl

8.16 Establish application environment for RAC

1) Hardware configuration

1.1 Desktops – (DELL Optiplex 755) – 5 Nos

Node-1 & Node-2      For 2 Middle-tier nodes

Node-3 & Node-4      For 2 Database-tier Nodes (For RAC)

Node-5               For shared storage using iSCSI/Openfiler

Node-5 Two Physical disks (Internal or External)

·         1^st SATA disk for operating system and Openfiler application,

·         2^nd SATA disk for as a single "Volume Group" to be used for all shared disk storage requirements )

2) Install Linux OS and required (For DB nodes)

Only the disk partitioning, NIC configuration portions while installation are highlighted below

2.1 Disk Partitioning Setup

·         Select [Remove all partitions on selected drives and create default layout]

·         Check the option to [Review and modify partitioning layout].

·         Click [Next] to continue.

You will then be prompted with a dialog window asking if you really want to remove all Linux partitions.

·         Click [Yes] to acknowledge this warning.

2.2 Partitioning

The installer will choose 100MB for /boot,

Double the amount of RAM (systems with >= 2,048MB RAM) or an amount equal to RAM (systems with < 2,048MB RAM) for swap, and the rest going to the root (/) partition.

From RHEL 4, the installer will create the same disk configuration as just noted but will create them using the Logical Volume Manager (LVM).

For example, it will partition the first hard drive (/dev/hda for my configuration) into two partitions —

One for the /boot partition (/dev/hda1) and the remainder of the disk dedicate to a LVM named VolGroup00 (/dev/hda2).

The LVM Volume Group (VolGroup00) is then partitioned into two LVM partitions - one for the root file system (/) and another for swap.

The main concern during the partitioning phase is to ensure enough swap space is allocated as required by Oracle (which is a multiple of the available RAM). The following is Oracle's requirement for swap space:

Available RAM	Swap Space Required
Between 1,024MB and 2,048MB	1.5 times the size of RAM
Between 2,049MB and 8,192MB	Equal to the size of RAM
More than 8,192MB	.75 times the size of RAM

For the purpose of this install, we will accept all automatically preferred sizes. (Including 4,096MB for swap since we have 2,048MB of RAM installed.

Once you are satisfied with the disk layout, click

·         [Next] to continue.

2.3 Boot Loader Configuration

The installer will use the GRUB boot loader by default. To use the GRUB boot loader, accept all default values and click [Next] to continue.

2.4 Network Configuration

This screen should have successfully detected each of the network devices. Since we will be using this machine to host an Oracle instance, there will be several changes that need to be made to the network configuration. The settings you make here will, of course, depend on your network configuration. The key point to make is that the machine should never be configured with DHCP since it will be used to host an Oracle instance. You will need to configure the machine with static IP addresses. You will also need to configure the server with a real host name.

First, make sure that each of the network devices are checked to [Active on boot]. The installer may choose to not activate eth1 by default.

Second,[Edit] both eth0 and eth1 as follows. Verify that the option "Enable IPv4 support" is selected. Click off the option to use "Dynamic IP configuration (DHCP)" by selecting the "Manual configuration" radio button and configure a static IP address and Netmask for your environment. Click off the option to "Enable IPv6 support". You may choose to use different IP addresses for both eth0 and eth1 that we have documented in this guide and that is OK. Put eth1 (the interconnect) on a different subnet than eth0 (the public network):

eth0:
- Check ON the option to [Enable IPv4 support]
- Check OFF the option to use [Dynamic IP configuration (DHCP)] - (select Manual configuration)
   IPv4 Address: 192.168.1.100
   Prefix (Netmask): 255.255.255.0
- Check OFF the option to [Enable IPv6 support]

eth1:
- Check ON the option to [Enable IPv4 support]
- Check OFF the option to use [Dynamic IP configuration (DHCP)] - (select Manual configuration)
   IPv4 Address: 192.168.2.100
   Prefix (Netmask): 255.255.255.0
- Check OFF the option to [Enable IPv6 support]

Continue by manually setting your hostname. We will use "linux1" for the first node and "linux2" for the second. Finish this dialog off by supplying your gateway and DNS servers.

2.5 Package Installation Defaults

·         Desktop Environments

o    GNOME Desktop Environment

·         Applications

o    Editors

o    Graphical Internet

o    Text-based Internet

·         Development

o    Development Libraries

o    Development Tools

o    Legacy Software Development

·         Servers

o    Server Configuration Tools

·         Base System

o    Administration Tools

o    Base

o    Java

o    Legacy Software Support

o    System Tools

o    X Window System

In addition to the above packages, select any additional packages you wish to install for this node keeping in mind to NOT de-select any of the "default" RPM packages. After selecting the packages to install click [Next] to continue.

2.6 Firewall

On this screen, make sure to select the [Disabled] option and click [Forward] to continue.

You will be prompted with a warning dialog about not setting the firewall. When this occurs, click [Yes] to continue.

2.7 Create User

Create any additional (non-oracle) operating system user accounts if desired and click [Forward] to continue. For the purpose of this article, We will not be creating any additional operating system accounts. We will be creating the "oracle" user account during the Oracle database installation later in this guide.

If you chose not to define any additional operating system user accounts, click [Continue] to acknowledge the warning dialog.

2.8 Perform the same installation on the second node

After completing the Linux installation on the first node, repeat the above steps for the second node (linux2).

eth0:
- Check ON the option to [Enable IPv4 support]
- Check OFF the option to [Use dynamic IP configuration (DHCP)] - (select Manual configuration)
   IPv4 Address: 192.168.1.101
   Prefix (Netmask): 255.255.255.0
- Check OFF the option to [Enable IPv6 support]

eth1:
- Check ON the option to [Enable IPv4 support]
- Check OFF the option to [Use dynamic IP configuration (DHCP)] - (select Manual configuration)
   IPv4 Address: 192.168.2.101
   Prefix (Netmask): 255.255.255.0
- Check OFF the option to [Enable IPv6 support]

3) Install Linux RPM’s for Oracle RAC

3.1 64-bit (x86_64) Installations

·         binutils-2.17.50.0.6-2.el5

·         compat-libstdc++-296-2.96-138

·         compat-libstdc++-33-3.2.3-61

·         compat-libstdc++-33-3.2.3-61 (32 bit)

·         elfutils-libelf-0.125-3.el5

·         elfutils-libelf-0.125-3.el5 (32 bit)

·         elfutils-libelf-devel-0.125

·         gcc-4.1.1

·         gcc-c++-4.1.1

·         glibc-2.5-12

·         glibc-2.5-12 (32 bit)

·         glibc-common-2.5

·         glibc-devel-2.5-12

·         glibc-devel-2.5-12 (32 bit)

·         glibc-headers-2.5-12

·         libaio-0.3.106

·         libaio-0.3.106 (32 bit)

·         libaio-devel-0.3.106

·         libgcc-4.1.1

·         libgcc-4.1.1 (32 bit)

·         libstdc++-4.1.1

·         libstdc++-4.1.1 (32 bit)

·         libstdc++-devel-4.1.1-52.e15

·         libXp-1.0.0-8

·         libXp-1.0.0-8 (32 bit)

·         make-3.81-1.1

·         openmotif-2.2.3

·         sysstat-7.0.0

·         unixODBC-2.2.11

·         unixODBC-2.2.11 (32 bit)

·         unixODBC-devel-2.2.11

Each of the packages listed above can be found on CD #1, CD #2, CD #3, and CD #4 on the Linux (x86_64) CDs. While it is possible to query each individual package to determine which ones are missing and need to be installed, an easier method is to run the rpm -Uvh PackageName command from the five CDs as follows. For packages that already exist and are up to date, the RPM command will simply ignore the install and print a warning message to the console that the package is already installed. 

4) Network Configuration

Although we configured several of the network settings during the installation of OS, it is important to not skip this section as it contains critical steps that are required for a successful RAC environment.

4.1 Introduction to Network Settings

During the Linux O/S install we already configured the IP address and host name for both of the Oracle RAC nodes. We now need to configure the /etc/hosts file as well as adjusting several of the network settings for interconnect.

Both of the Oracle RAC nodes should have one static IP address for the public network and one static IP address for the private cluster interconnect. Do not use DHCP naming for the public IP address or interconnects; you need static IP addresses! The private interconnect should only be used by Oracle to transfer Cluster Manager and Cache Fusion related data along with data for the network storage server (Openfiler). Note that Oracle does not support using the public network interface for interconnect. You must have one network interface for the public network and another network interface for the private interconnect. For a production RAC implementation, interconnect should be at least gigabit (or more) and only be used by Oracle as well as having the network storage server (Openfiler) on a separate gigabit network.

4.2 Configuring Public and Private Network

In our two node example, we need to configure the network on both Oracle RAC nodes for access to the public network as well as their private interconnects. The easiest way to configure network settings in CentOS is with the program Network Configuration. This application can be started from the command-line as the "root" user account as follows:

# /usr/bin/system-config-network &

Do not use DHCP naming for the public IP address or interconnects - we need static IP addresses!

Using the Network Configuration application, you need to configure both NIC devices as well as the /etc/hosts file. Both of these tasks can be completed using the Network Configuration GUI. Notice that the /etc/hosts settings are the same for both nodes and that We removed any entry that has to do with IPv6 (for example, ::1 localhost6.localdomain6 localhost6).

Our example configuration will use the following settings: Oracle RAC Node 1 - (linux1)
Device	IP Address	Subnet	Gateway	Purpose
eth0	192.168.1.100	255.255.255.0	192.168.1.1	Connects linux1 to the public network
eth1	192.168.2.100	255.255.255.0		Connects linux1 (interconnect) to linux2 (linux2-priv)
/etc/hosts
127.0.0.1        localhost.localdomain localhost # Public Network - (eth0) 192.168.1.100    linux1 192.168.1.101    linux2 # Private Interconnect - (eth1) 192.168.2.100    linux1-priv 192.168.2.101    linux2-priv # Public Virtual IP (VIP) addresses - (eth0:1) 192.168.1.200    linux1-vip 192.168.1.201    linux2-vip # Private Storage Network for Openfiler - (eth1) 192.168.1.195    openfiler1 192.168.2.195    openfiler1-priv

Oracle RAC Node 2 - (linux2)
Device	IP Address	Subnet	Gateway	Purpose
eth0	192.168.1.101	255.255.255.0	192.168.1.1	Connects linux2 to the public network
eth1	192.168.2.101	255.255.255.0		Connects linux2 (interconnect) to linux1 (linux1-priv)
/etc/hosts
127.0.0.1        localhost.localdomain localhost # Public Network - (eth0) 192.168.1.100    linux1 192.168.1.101    linux2 # Private Interconnect - (eth1) 192.168.2.100    linux1-priv 192.168.2.101    linux2-priv # Public Virtual IP (VIP) addresses - (eth0:1) 192.168.1.200    linux1-vip 192.168.1.201    linux2-vip # Private Storage Network for Openfiler - (eth1) 192.168.1.195    openfiler1 192.168.2.195    openfiler1-priv

Note that the virtual IP addresses only need to be defined in the /etc/hosts file (or your DNS) for both Oracle RAC nodes. The public virtual IP addresses will be configured automatically by Oracle Clusterware when you run the Oracle Universal Installer, which starts Oracle's Virtual Internet Protocol Configuration Assistant (VIPCA). All virtual IP addresses will be activated when the srvctl start nodeapps -n command is run. This is the Host Name/IP Address that will be configured in the client(s) tnsnames.ora file (more details later).

In the screen shots below, only Oracle RAC Node 1 (linux1) is shown. Be sure to make all the proper network settings to both Oracle RAC nodes.

Network Configuration Screen - Node 1 (linux1)

Ethernet Device Screen - eth0 (linux1)

Ethernet Device Screen - eth1 (linux1)

Network Configuration Screen - /etc/hosts (linux1)

Once the network is configured, you can use the ifconfig command to verify everything is working. The following example is from linux1:

# /sbin/ifconfig -a

eth0      Link encap:Ethernet  HWaddr 00:14:6C:76:5C:71

          inet addr:192.168.1.100  Bcast:192.168.1.255  Mask:255.255.255.0

          inet6 addr: fe80::214:6cff:fe76:5c71/64 Scope:Link

          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1

          RX packets:3059 errors:0 dropped:0 overruns:0 frame:0

          TX packets:1539 errors:0 dropped:0 overruns:0 carrier:0

          collisions:0 txqueuelen:1000

          RX bytes:3460697 (3.3 MiB)  TX bytes:145612 (142.1 KiB)

          Interrupt:169 Base address:0xef00

eth1      Link encap:Ethernet  HWaddr 00:0E:0C:64:D1:E5

          inet addr:192.168.2.100  Bcast:192.168.2.255  Mask:255.255.255.0

          inet6 addr: fe80::20e:cff:fe64:d1e5/64 Scope:Link

          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1

          RX packets:0 errors:0 dropped:0 overruns:0 frame:0

          TX packets:11 errors:0 dropped:0 overruns:0 carrier:0

          collisions:0 txqueuelen:1000

          RX bytes:0 (0.0 b)  TX bytes:782 (782.0 b)

          Base address:0xddc0 Memory:fe9c0000-fe9e0000

lo        Link encap:Local Loopback

          inet addr:127.0.0.1  Mask:255.0.0.0

          inet6 addr: ::1/128 Scope:Host

          UP LOOPBACK RUNNING  MTU:16436  Metric:1

          RX packets:1764 errors:0 dropped:0 overruns:0 frame:0

          TX packets:1764 errors:0 dropped:0 overruns:0 carrier:0

          collisions:0 txqueuelen:0

          RX bytes:1991946 (1.8 MiB)  TX bytes:1991946 (1.8 MiB)

sit0      Link encap:IPv6-in-IPv4

          NOARP  MTU:1480  Metric:1

          RX packets:0 errors:0 dropped:0 overruns:0 frame:0

          TX packets:0 errors:0 dropped:0 overruns:0 carrier:0

          collisions:0 txqueuelen:0

          RX bytes:0 (0.0 b)  TX bytes:0 (0.0 b)

4.3 About Virtual IP

Why do we have a Virtual IP (VIP) in 10g? Why does it just return a dead connection when its primary node fails?

It's all about availability of the application. When a node fails, the VIP associated with it is supposed to be automatically failed over to some other node. When this occurs, two things happen.

·         The new node re-arps the world indicating a new MAC address for the address. For directly connected clients, this usually causes them to see errors on their connections to the old address.

·         Subsequent packets sent to the VIP go to the new node, which will send error RST packets back to the clients. This results in the clients getting errors immediately.

This means that when the client issues SQL to the node that is now down, or traverses the address list while connecting, rather than waiting on a very long TCP/IP time-out (~10 minutes), the client receives a TCP reset. In the case of SQL, this is ORA-3113. In the case of connect, the next address in tnsnames is used.

Without using VIPs, clients connected to a node that died will often wait a 10 minute TCP timeout period before getting an error. As a result, you don't really have a good HA solution without using VIPs.

Source - Metalink: "RAC Frequently Asked Questions" (Note:220970.1)

4.4 Confirm the RAC Node Name is Not Listed in Loopback Address

Ensure that the node names (linux1 or linux2) are not included for the loopback address in the /etc/hosts file. If the machine name is listed in the in the loopback address entry as below:

    127.0.0.1        linux1 localhost.localdomain localhost

it will need to be removed as shown below:

    127.0.0.1        localhost.localdomain localhost

If the RAC node name is listed for the loopback address, you will receive the following error during the RAC installation: ORA-00603: ORACLE server session terminated by fatal error or ORA-29702: error occurred in Cluster Group Service operation

4.5 Confirm localhost is defined in the /etc/hosts file for the loopback address

Ensure that the entry for localhost.localdomain and localhost are included for the loopback address in the /etc/hosts file for each of the Oracle RAC nodes:

    127.0.0.1        localhost.localdomain localhost

If an entry does not exist for localhost in the /etc/hosts file, Oracle Clusterware will be unable to start the application resources — notably the ONS process. The error would indicate "Failed to get IP for localhost" and will be written to the log file for ONS. For example: CRS-0215 could not start resource 'ora.linux1.ons'. Check log file "/u01/app/crs/log/linux1/racg/ora.linux1.ons.log" for more details. The ONS log file will contain lines similar to the following: Oracle Database 10g CRS Release 10.2.0.1.0 Production Copyright 1996, 2005 Oracle. All rights reserved. 2007-04-14 13:10:02.729: [ RACG][3086871296][13316][3086871296][ora.linux1.ons]: Failed to get IP for localhost (1) Failed to get IP for localhost (1) Failed to get IP for localhost (1) onsctl: ons failed to start ...

4.6 Adjusting Network Settings

With Oracle 9.2.0.1 and later, Oracle makes use of UDP as the default protocol on Linux for inter-process communication (IPC), such as Cache Fusion and Cluster Manager buffer transfers between instances within the RAC cluster.

Oracle strongly suggests to adjust the default and maximum receive buffer size (SO_RCVBUF socket option) to 1024KB and the default and maximum send buffer size (SO_SNDBUF socket option) to 256KB.

The receive buffers are used by TCP and UDP to hold received data until it is read by the application. The receive buffer cannot overflow because the peer is not allowed to send data beyond the buffer size window. This means that datagrams will be discarded if they don't fit in the socket receive buffer, potentially causing the sender to overwhelm the receiver.

The default and maximum window size can be changed in the /proc file system without reboot: # sysctl -w net.core.rmem_default=1048576 net.core.rmem_default = 1048576 # sysctl -w net.core.rmem_max=1048576 net.core.rmem_max = 1048576 # sysctl -w net.core.wmem_default=262144 net.core.wmem_default = 262144 # sysctl -w net.core.wmem_max=262144 net.core.wmem_max = 262144

The above commands made the changes to the already running OS. You should now make the above changes permanent (for each reboot) by adding the following lines to the /etc/sysctl.conf file for both nodes in your RAC cluster:

# +---------------------------------------------------------+

# | ADJUSTING NETWORK SETTINGS                              |

# +---------------------------------------------------------+

# | With Oracle 9.2.0.1 and onwards, Oracle now makes use   |

# | of UDP as the default protocol on Linux for             |

# | inter-process communication (IPC), such as Cache Fusion |

# | and Cluster Manager buffer transfers between instances  |

# | within the RAC cluster. Oracle strongly suggests to     |

# | adjust the default and maximum receive buffer size      |

# | (SO_RCVBUF socket option) to 1024KB, and the default    |

# | and maximum send buffer size (SO_SNDBUF socket option)  |

# | to 256KB. The receive buffers are used by TCP and UDP   |

# | to hold received data until it is read by the           |

# | application. The receive buffer cannot overflow because |

# | the peer is not allowed to send data beyond the buffer  |

# | size window. This means that datagrams will be          |

# | discarded if they don't fit in the socket receive       |

# | buffer. This could cause the sender to overwhelm the    |

# | receiver.                                               |

# +---------------------------------------------------------+

# +---------------------------------------------------------+

# | Default setting in bytes of the socket "receive" buffer |

# | which may be set by using the SO_RCVBUF socket option.  |

# +---------------------------------------------------------+

net.core.rmem_default=1048576

# +---------------------------------------------------------+

# | Maximum setting in bytes of the socket "receive" buffer |

# | which may be set by using the SO_RCVBUF socket option.  |

# +---------------------------------------------------------+

net.core.rmem_max=1048576

# +---------------------------------------------------------+

# | Default setting in bytes of the socket "send" buffer    |

# | which may be set by using the SO_SNDBUF socket option.  |

# +---------------------------------------------------------+

net.core.wmem_default=262144

# +---------------------------------------------------------+

# | Maximum setting in bytes of the socket "send" buffer    |

# | which may be set by using the SO_SNDBUF socket option.  |

# +---------------------------------------------------------+

net.core.wmem_max=262144

4.7 Check and turn off UDP ICMP rejections:

During the Linux installation process, We indicated to not configure the firewall option. By default the option to configure a firewall is selected by the installer. This has burned me several times so We like to do a double check that the firewall option is not configured and to ensure udp ICMP filtering is turned off.

If UDP ICMP is blocked or rejected by the firewall, the Oracle Clusterware software will crash after several minutes of running. When the Oracle Clusterware process fails, you will have something similar to the following in the _evmocr.log file:

08/29/2005 22:17:19

oac_init:2: Could not connect to server, clsc retcode = 9

08/29/2005 22:17:19

a_init:12!: Client init unsuccessful : [32]

ibctx:1:ERROR: INVALID FORMAT

proprinit:problem reading the bootblock or superbloc 22

When experiencing this type of error, the solution is to remove the udp ICMP (iptables) rejection rule - or to simply have the firewall option turned off. The Oracle Clusterware software will then start to operate normally and not crash. The following commands should be executed as the root user account:

1.  Check to ensure that the firewall option is turned off. If the firewall option is stopped (like it is in my example below) you do not have to proceed with the following steps.

2.  # /etc/rc.d/init.d/iptables status

Firewall is stopped.

3.  If the firewall option is operating you will need to first manually disable UDP ICMP rejections:

4.  # /etc/rc.d/init.d/iptables stop

5.   

6.  Flushing firewall rules: [  OK  ]

7.  Setting chains to policy ACCEPT: filter [  OK  ]

Unloading iptables modules: [  OK  ]

8.  Then, to turn UDP ICMP rejections off for next server reboot (which should always be turned off):

# chkconfig iptables off

To be continued ....... Read Part II

HAPPY LEARNING!