How to recreate SCAN listeners to align nslookup IP adresses and SCAN listeners

Overview

- A SCAN  name which can resolve upto maximum three IP address 
- For each of these IP addresses a  SCAN VIP or SCAN IP is available 
- Each Scan VIP has a SCAN Listener generated corresponding to it. 
  If there are three SCAN VIP's three SCAN Listeners will be generated.
- For a SCAN name returning 3 addresses 3 SCAN listeners should be created
- SCAN VIP and SCAN Listener works as a pair when SCAN VIP fails over to other node, the corresponding 
  SCAN listener will also be failed over to the same node
- If SCAN listeners are up and running you should be able to ping them

Problem: For a SCAN returning 3 IP addresess only 2 SCAN listeners are created –> ping fails

[root@grac43 ~]# nslookup grac4-scan
Server:        192.168.1.50
Address:    192.168.1.50#53

Non-authoritative answer:
Name:    grac4-scan.grid4.example.com
Address: 192.168.1.170
Name:    grac4-scan.grid4.example.com
Address: 192.168.1.165
Name:    grac4-scan.grid4.example.com
Address: 192.168.1.168
--> For SCAN name  grac4-scan 3 IP addresses were returned - Verify with ping 
[root@grac43 ~]# ping -c 2 192.168.1.170
PING 192.168.1.170 (192.168.1.170) 56(84) bytes of data.
64 bytes from 192.168.1.170: icmp_seq=1 ttl=64 time=0.015 ms
64 bytes from 192.168.1.170: icmp_seq=2 ttl=64 time=0.021 ms
--- 192.168.1.170 ping statistics ---
2 packets transmitted, 2 received, 0% packet loss, time 999ms
rtt min/avg/max/mdev = 0.015/0.018/0.021/0.003 ms

[root@grac43 ~]# ping -c  2 192.168.1.165
PING 192.168.1.165 (192.168.1.165) 56(84) bytes of data.
64 bytes from 192.168.1.165: icmp_seq=1 ttl=64 time=0.010 ms
64 bytes from 192.168.1.165: icmp_seq=2 ttl=64 time=0.231 ms
--- 192.168.1.165 ping statistics ---
2 packets transmitted, 2 received, 0% packet loss, time 999ms
rtt min/avg/max/mdev = 0.010/0.120/0.231/0.111 ms
[root@grac43 ~]#  ping -c  2 192.168.1.168
PING 192.168.1.168 (192.168.1.168) 56(84) bytes of data.
From 192.168.1.103 icmp_seq=1 Destination Host Unreachable
From 192.168.1.103 icmp_seq=2 Destination Host Unreachable
--> Ping is not working for for IP address 192.168.1.168
--- 192.168.1.168 ping statistics ---
2 packets transmitted, 0 received, +2 errors, 100% packet loss, time 3007ms
pipe 2
--> Ping fails for 1 of 3 IP addresses 

Verify SCAN listener Setup

[root@grac41 network-scripts]# srvctl config scan_listener
SCAN Listener LISTENER_SCAN1 exists. Port: TCP:1521
SCAN Listener LISTENER_SCAN2 exists. Port: TCP:1521
--> Only 2 SCAN Listerns  
[root@grac41 network-scripts]#   srvctl config scan
SCAN name: grac4-scan.grid4.example.com, Network: 1/192.168.1.0/255.255.255.0/eth1
SCAN VIP name: scan1, IP: /grac4-scan.grid4.example.com/192.168.1.165
SCAN VIP name: scan2, IP: /grac4-scan.grid4.example.com/192.168.1.170
--> Only 2 SCAN VIPs 

Recreate SCAN listener

[grid@grac41 ~/NET]$  srvctl stop scan_listener
[grid@grac41 ~/NET]$  srvctl stop scan

Verify OLD configuration: 
[grid@grac41 ~/NET]$ srvctl config scan_listener
SCAN Listener LISTENER_SCAN1 exists. Port: TCP:1521
SCAN Listener LISTENER_SCAN2 exists. Port: TCP:1521
[grid@grac41 ~/NET]$  srvctl config scan
SCAN name: grac4-scan.grid4.example.com, Network: 1/192.168.1.0/255.255.255.0/eth1
SCAN VIP name: scan1, IP: /grac4-scan.grid4.example.com/192.168.1.165
SCAN VIP name: scan2, IP: /grac4-scan.grid4.example.com/192.168.1.170

Modify and recreate SCAN listeners
[root@grac41 NET]#  srvctl modify scan -n  grac4-scan.grid4.example.com
[root@grac41 NET]#  srvctl config scan
SCAN name: grac4-scan.grid4.example.com, Network: 1/192.168.1.0/255.255.255.0/eth1
SCAN VIP name: scan1, IP: <not assigned>
SCAN VIP name: scan2, IP: <not assigned>
SCAN VIP name: scan3, IP: <not assigned>

[root@grac41 NET]# srvctl modify scan_listener -u
[root@grac41 NET]# srvctl config scan
SCAN name: grac4-scan.grid4.example.com, Network: 1/192.168.1.0/255.255.255.0/eth1
SCAN VIP name: scan1, IP: <not assigned>
SCAN VIP name: scan2, IP: <not assigned>
SCAN VIP name: scan3, IP: <not assigned>
[root@grac41 NET]#  srvctl config scan_listener
SCAN Listener LISTENER_SCAN1 exists. Port: TCP:1521
SCAN Listener LISTENER_SCAN2 exists. Port: TCP:1521
SCAN Listener LISTENER_SCAN3 exists. Port: TCP:1521
[root@grac41 NET]# srvctl start scan_listener
[root@grac41 NET]# srvctl config scan
SCAN name: grac4-scan.grid4.example.com, Network: 1/192.168.1.0/255.255.255.0/eth1
SCAN VIP name: scan1, IP: /grac4-scan.grid4.example.com/192.168.1.171
SCAN VIP name: scan2, IP: /grac4-scan.grid4.example.com/192.168.1.251
SCAN VIP name: scan3, IP: /grac4-scan.grid4.example.com/192.168.1.173

Verify that SCAN listeners are responding 
[root@grac41 NET]# ping 192.168.1.171
PING 192.168.1.171 (192.168.1.171) 56(84) bytes of data.
64 bytes from 192.168.1.171: icmp_seq=1 ttl=64 time=0.021 ms
64 bytes from 192.168.1.171: icmp_seq=2 ttl=64 time=0.024 ms
--- 192.168.1.171 ping statistics ---
2 packets transmitted, 2 received, 0% packet loss, time 1411ms
rtt min/avg/max/mdev = 0.021/0.022/0.024/0.005 ms

[root@grac41 NET]#  ping  192.168.1.251
PING 192.168.1.251 (192.168.1.251) 56(84) bytes of data.
64 bytes from 192.168.1.251: icmp_seq=1 ttl=64 time=2.02 ms
64 bytes from 192.168.1.251: icmp_seq=2 ttl=64 time=1.47 ms
--- 192.168.1.251 ping statistics ---
2 packets transmitted, 2 received, 0% packet loss, time 1121ms
rtt min/avg/max/mdev = 1.477/1.750/2.023/0.273 ms

[root@grac41 NET]# ping 192.168.1.173
PING 192.168.1.173 (192.168.1.173) 56(84) bytes of data.
64 bytes from 192.168.1.173: icmp_seq=1 ttl=64 time=2.62 ms
64 bytes from 192.168.1.173: icmp_seq=2 ttl=64 time=0.368 ms
^C
--- 192.168.1.173 ping statistics ---
2 packets transmitted, 2 received, 0% packet loss, time 1378ms
rtt min/avg/max/mdev = 0.368/1.498/2.629/1.131 ms

--> Prolbem fixed !

Verify  GNS scan-vip addresses

[root@grac41 NET]# srvctl config gns -a -l
GNS is enabled.
GNS is listening for DNS server requests on port 53
GNS is using port 5353 to connect to mDNS
GNS status: OK
Domain served by GNS: grid4.example.com
GNS version: 11.2.0.4.0
GNS VIP network: ora.net1.network
Name            Type Value
grac4-scan      A    192.168.1.171
grac4-scan      A    192.168.1.173
grac4-scan      A    192.168.1.251
grac4-scan1-vip A    192.168.1.171
grac4-scan2-vip A    192.168.1.251
grac4-scan3-vip A    192.168.1.173
grac41-vip      A    192.168.1.167
grac42-vip      A    192.168.1.178
grac43-vip      A    192.168.1.177

Reference

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