DNSMASQ not able to nslookup-> ;; connection timed out; no servers could be reached

[abhi123]

I want to create Oracle 2 Node RAC on my Virtual Box 6.1, which hosts OEL 7.9 server.
I have given the below entries in /etc/hosts :
127.0.0.1 localhost localhost.localdomain localhost4 localhost4.localdomain4
::1 localhost localhost.localdomain localhost6 localhost6.localdomain6
#127.0.0.1 localhost.localdomain localhost
# Public
192.168.56.101 node1.localdomain node1
192.168.56.102 node2.localdomain node2
# Private
192.168.1.101 node1-priv.localdomain node1-priv
192.168.1.102 node2-priv.localdomain node2-priv
# Virtual
192.168.56.111 node1-vip.localdomain node1-vip
192.168.56.112 node2-vip.localdomain node2-vip
# SCAN
192.168.56.121 node-scan.localdomain node-scan
192.168.56.122 node-scan.localdomain node-scan
192.168.56.123 node-scan.localdomain node-scan


/etc/resolv.conf holding the below entries :
search localdomain
nameserver 192.168.56.1


DNSMASQ service is active and running :
[root@node2 network-scripts]# systemctl status dnsmasq
● dnsmasq.service - DNS caching server.
Loaded: loaded (/usr/lib/systemd/system/dnsmasq.service; enabled; vendor preset: disabled)
Active: active (running) since Sun 2021-01-24 13:17:51 IST; 12min ago
Main PID: 27061 (dnsmasq)
CGroup: /system.slice/dnsmasq.service
└─27061 /usr/sbin/dnsmasq -k

Jan 24 13:17:51 node2.localdomain systemd[1]: Stopped DNS caching server..
Jan 24 13:17:51 node2.localdomain systemd[1]: Started DNS caching server..
Jan 24 13:17:51 node2.localdomain dnsmasq[27061]: started, version 2.76 cachesize 150
Jan 24 13:17:51 node2.localdomain dnsmasq[27061]: compile time options: IPv6 GNU-getopt DBus no-i18n IDN DHCP DHCPv6 no-Lua TF...notify
Jan 24 13:17:51 node2.localdomain dnsmasq[27061]: using local addresses only for domain localdomain
Jan 24 13:17:51 node2.localdomain dnsmasq[27061]: reading /etc/resolv.conf
Jan 24 13:17:51 node2.localdomain dnsmasq[27061]: using local addresses only for domain localdomain
Jan 24 13:17:51 node2.localdomain dnsmasq[27061]: using nameserver 192.168.56.1#53
Jan 24 13:17:51 node2.localdomain dnsmasq[27061]: read /etc/hosts - 11 addresses
Hint: Some lines were ellipsized, use -l to show in full.

Below is the configuration of my IPs :
[root@node2 network-scripts]# ifconfig
enp0s3: flags=4163<UP,BROADCAST,RUNNING,MULTICAST> mtu 1500
ether 08:00:27:55:df:5d txqueuelen 1000 (Ethernet)
RX packets 1517959 bytes 1746410780 (1.6 GiB)
RX errors 0 dropped 0 overruns 0 frame 0
TX packets 314566 bytes 19078121 (18.1 MiB)
TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0

enp0s8: flags=4163<UP,BROADCAST,RUNNING,MULTICAST> mtu 1500
inet 192.168.56.102 netmask 255.255.255.0 broadcast 192.168.56.255
inet6 fe80::af50:c617:57b:b9b9 prefixlen 64 scopeid 0x20<link>
ether 08:00:27:86:62:18 txqueuelen 1000 (Ethernet)
RX packets 191 bytes 18075 (17.6 KiB)
RX errors 0 dropped 0 overruns 0 frame 0
TX packets 607 bytes 60723 (59.2 KiB)
TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0

enp0s9: flags=4163<UP,BROADCAST,RUNNING,MULTICAST> mtu 1500
inet 192.168.1.102 netmask 255.255.255.0 broadcast 192.168.1.255
inet6 fe80:e53:a89:1fe0 prefixlen 64 scopeid 0x20<link>
ether 08:00:27:47:49:50 txqueuelen 1000 (Ethernet)
RX packets 0 bytes 0 (0.0 B)
RX errors 0 dropped 0 overruns 0 frame 0
TX packets 321 bytes 42936 (41.9 KiB)
TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0

lo: flags=73<UP,LOOPBACK,RUNNING> mtu 65536
inet 127.0.0.1 netmask 255.0.0.0
inet6 ::1 prefixlen 128 scopeid 0x10<host>
loop txqueuelen 0 (Local Loopback)
RX packets 190 bytes 16195 (15.8 KiB)
RX errors 0 dropped 0 overruns 0 frame 0
TX packets 190 bytes 16195 (15.8 KiB)
TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0

virbr0: flags=4099<UP,BROADCAST,MULTICAST> mtu 1500
inet 192.168.122.1 netmask 255.255.255.0 broadcast 192.168.122.255
ether 52:54:00:56:2d:c6 txqueuelen 0 (Ethernet)
RX packets 0 bytes 0 (0.0 B)
RX errors 0 dropped 0 overruns 0 frame 0
TX packets 0 bytes 0 (0.0 B)
TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0


Still I am unable to nslookup my host and scan entries :

[root@node2 network-scripts]# nslookup node2
;; connection timed out; no servers could be reached

[root@node2 network-scripts]# nslookup node-scan
;; connection timed out; no servers could be reached


I am still stuck in here. Request your help to proceed further

[scottgus1]

The first thing to check is if you can ping one VM's IP address from the other VM. (Confirm that all firewalls etc are configured to allow Ping or ICMP Echo Request.) If you can ping, then the Virtualbox network is working and the connection troubles are in the other settings.

Each VM connected to the 192.168.56.### range should be able to ping all the .56 IP addresses in the listing above. Likewise the two 192.168.1.###'s should be able to ping each other.

If these pings go through, the other configurations are at fault.

If you have trouble pinging, find each VM's .box file and post it:
Right-click the VM in the main Virtualbox window's VM list, choose Show in Explorer. Zip the VM's .vbox file (not the .vbox-prev file), and post the zip file, using the forum's Upload Attachment tab. (Configure your host OS to show all extensions if the folder that opens does not show a .vbox file.)