Explore network interfaces for ODA X11-2

Thank you very much for your interest. In this article I will walk you through various network interfaces and their usage in ODA nodes. Hope you will learn some architectural background of ODA system.

Most linux system boots with run level 3 which is multi user mode without GUI.To check your current run level in linux system use who -r command from root user.

Use below command to find startup script under run level 3

ls -ltr /etc/rc.d/rc3.d | sort -k 9
lrwxrwxrwx. 1 root root  17 Jul 17 10:57 K85opensmd -> ../init.d/opensmd
lrwxrwxrwx. 1 root root  17 Jul 17 11:37 S10network -> ../init.d/network
-rwx------. 1 root root 519 Feb 14  2025 S90asr-start
lrwxrwxrwx  1 root root  15 Jul 17 13:09 S96afd -> /etc/init.d/afd
lrwxrwxrwx  1 root root  17 Jul 17 13:08 S96ohasd -> /etc/init.d/ohasd

Please pay attention to the softlink name here.Link which starts with K are kill scriptts it implies before it is rebooted kill scripts are executed but here we are interested to explore startup scripts which start with S.

1st script which starts during startup is network which helps to bring up all network interface.Now here is an important observation.All network scripts are placed under /etc/sysconfig/network-scripts directory and can be found like below

  ls -ltr /etc/sysconfig/network-scripts/ifcfg*

-rw-r--r--. 1 root root 264 Oct 10 07:08 /etc/sysconfig/network-scripts/ifcfg-lo

-rw-r--r--  1 root root 160 Oct 10 07:26 /etc/sysconfig/network-scripts/ifcfg-em1

-rw-r--r--  1 root root 195 Oct 10 07:26 /etc/sysconfig/network-scripts/ifcfg-p1p1

-rw-r--r--  1 root root 195 Oct 10 07:26 /etc/sysconfig/network-scripts/ifcfg-p1p2

-rw-r--r--  1 root root 186 Oct 10 07:26 /etc/sysconfig/network-scripts/ifcfg-p5p1

-rw-r--r--  1 root root 186 Oct 10 07:26 /etc/sysconfig/network-scripts/ifcfg-p4p1

-rw-r--r--  1 root root 270 Oct 10 07:26 /etc/sysconfig/network-scripts/ifcfg-icbond0

-rw-r--r--  1 root root 139 Oct 10 07:51 /etc/sysconfig/network-scripts/ifcfg-pubnet

-rw-r--r--  1 root root 471 Oct 10 07:52 /etc/sysconfig/network-scripts/ifcfg-icbond0.100

-rw-r--r--  1 root root 122 Oct 10 07:52 /etc/sysconfig/network-scripts/ifcfg-privasm

-rw-r--r--  1 root root 218 Oct 10 07:52 /etc/sysconfig/network-scripts/ifcfg-btbond1

-rw-r--r--  1 root root 323 Oct 10 09:02 /etc/sysconfig/network-scripts/ifcfg-btbond2

-rw-r--r--  1 root root 366 Oct 10 09:04 /etc/sysconfig/network-scripts/ifcfg-p5p2

-rw-r--r--  1 root root 366 Oct 10 09:04 /etc/sysconfig/network-scripts/ifcfg-p4p2

Same can be validated like below using command

ip a

Now if we use below command find the networks used by oda we only find below

odacli list-networks

ID                                     Name                 NIC          Interface Type  Subnet Mask        Gateway            VLAN ID  Node Networks                                        

-------------------------------------- -------------------- ------------ --------------- ------------------ ------------------ -------- ---------------------------------------------------------------------------

xxxxxx   Public-network       pubnet       BRIDGE          255.255.254.0      10.xx.xx.xx                 [IP Address on node0: 10.xx.xx.xx, IP Address on node1: 10.xx.xx.xx]

xxxxxx  Private-network      icbond0      INTERNAL        255.255.255.0                                  [IP Address on node0: 192.xx.xx.xx, IP Address on node1: 192.xx.xx.xx]

xxxxxx   storage              btbond2      BOND            255.255.254.0      10.xx.xx.xx        100      [IP Address on node0: 10.xx.xx.xx, IP Address on node1: 10.xx.xx.xx]

xxxxxxx  ASM-network          privasm      BRIDGE          255.255.255.128                                [IP Address on node0: 192.xx.xx.xx, IP Address on node1: 192.xx.xx.xx]

So we see there are only four interface.

pubnet:-

Lets explore interface pubnet whose property can be found in

/etc/sysconfig/network-scripts/ifcfg-pubnet which will have a static public address.

There are 2 more virtual interface pubnet:1 which maps to VIP and pubnet:2 which maps to SCAN IP

Local listener uses this public-ip in one of the address list.

Now what is VIP then?

Scan listener forwards connection request to Local listener using this node level VIP.Basically this is kind of network abstraction where application can connect without using actual public ip.

Now here is an interesting thing to understand.pubnet and btbond1 refers to same mac address which means btbond1 is the name used by kernel and pubnet is user defined name.

use ifcconfig btbond1 command to find TX packets statistics which says amount of data transmitted and RX packets statistics which says about amount of data received

icbond0:-

Property of this interface can be found in /etc/sysconfig/network-scripts/ifcfg-icbond0.This is a bonded interface for supporting network traffic between rac nodes and connect two physical network interface

called p1p1 (active) and p1p2(passive).

you can see below line to find which one is active interface

BONDING_OPTS="mode=active-backup miimon=100 primary=p1p1"

This is a high speed network interface of 25 GB/sec and can be verified like below

ethtool icbond0

btbond2:-

Property of this interface can be found in /etc/sysconfig/network-scripts/ifcfg-btbond2 .This is also a bonded interface which has active interface p5p2.This is a high speed network interface of 25 GB/sec and can be verified like below

ethtool p5p2

privasm:-

Property of this interface can be found in /etc/sysconfig/network-scripts/ifcfg-privasm.This interface is solely used by ASM which you can  validate using below command

 ifconfig privasm
privasm: flags=4163<UP,BROADCAST,RUNNING,MULTICAST>  mtu 9000
        inet 192.xx.xx.xx  netmask 255.255.255.128  broadcast 192.xx.xx.xx
        ether xx:xx:xx  txqueuelen 1000  (Ethernet)
        RX packets 15502  bytes 2170494 (2.0 MiB)
        RX errors 0  dropped 0  overruns 0  frame 0
        TX packets 16361  bytes 2351497 (2.2 MiB)
        TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0

lsnrctl status ASMNET1LSNR_ASM

LSNRCTL for Linux: Version 19.0.0.0.0 - Production on 16-OCT-2025 23:22:07

Copyright (c) 1991, 2024, Oracle.  All rights reserved.

Connecting to (DESCRIPTION=(ADDRESS=(PROTOCOL=IPC)(KEY=ASMNET1LSNR_ASM)))

STATUS of the LISTENER

------------------------

Alias                     ASMNET1LSNR_ASM
Version                   TNSLSNR for Linux: Version 19.0.0.0.0 - Production
Start Date                10-OCT-2025 09:08:02
Uptime                    6 days 14 hr. 14 min. 4 sec
Trace Level               off
Security                  ON: Local OS Authentication
SNMP                      OFF
Listener Parameter File   /u01/app/19.26.0.0/grid/network/admin/listener.ora
Listener Log File         /u01/app/grid/diag/tnslsnr/tuslpmdmoda04a/asmnet1lsnr_asm/alert/log.xml
Listening Endpoints Summary...
  (DESCRIPTION=(ADDRESS=(PROTOCOL=ipc)(KEY=ASMNET1LSNR_ASM)))
  (DESCRIPTION=(ADDRESS=(PROTOCOL=tcp)(HOST=192.xx.xx.xx)(PORT=1525)))
Services Summary...
Service "+ASM" has 2 instance(s).
  Instance "+ASM1", status READY, has 2 handler(s) for this service...
  Instance "+ASM2", status READY, has 1 handler(s) for this service...
Service "+ASM_DATA" has 2 instance(s).
  Instance "+ASM1", status READY, has 2 handler(s) for this service...
  Instance "+ASM2", status READY, has 1 handler(s) for this service...
Service "+ASM_RECO" has 2 instance(s).
  Instance "+ASM1", status READY, has 2 handler(s) for this service...
  Instance "+ASM2", status READY, has 1 handler(s) for this service...
The command completed successfully

Hope you have learnt some useful topics about network interface...
Happy learning...