DNS cache
DNS Cache on VAPP
Oplon ADC does not make DNS requests on its own, but configurations can be set up that indirectly generate many DNS requests. One such case is the use of machine names and not addresses such as endpoint. This configuration is absolutely legitimate and creates additional flexibility in configuration, but in the presence of consumer firewalls or low-quality equipment it can cause problems within the datacenters.
In case we're in this situation, no problem, you can run DNS caches within the Virtual Appliances in a few moments.
DNSMasq installation and setup
Installing dnsmasq on virtual appliances is very simple and depending on the CentOS or Debian derivation deployment (e.g. RedHAT or Ubuntu) the action is as follows:
CentOS derivation
yum --y install dnsmasq
Debian derivation
apt-get install dnsmasq
Once installed, perform the following root steps for configuration:
- Edit /etc/dnsmasq.conf
vi /etc/dnsmasq.conf
- In /etc/dnsmasw.conf Change the following parameter from
#bogus-priv
a
bogus-priv
- Allocate the following directory
mkdir -p /var/log/dnsmasq
- Upload the following configuration to a new /etc/dnsmasq.d/lbl.conf file with the following values
log-facility : /var/log/dnsmasq/dnsmasq.log
log-async - 15
clear-on-reload
- Name resolution change
Change the name resolution through the network manager (nmtui) or through the /etc/resolv.conf file where the network manager is not present by putting localhost in the first position:
nameserver 127.0.0.1
nameserver 8.8.8.8 <- This is an example, to give you your DNS name
- Enabling the service
systemctl enable dnsmasq
systemctl start dnsmasq
systemctl status dnsmasq
dnsmasq.service - DNS caching server.
Loaded: loaded (/usr/lib/systemd/system/dnsmasq.service; enabled; vendor preset: disabled)
Active: active (running) since Wed XXXXXXXXXXXX
Main PID: 39771 (dnsmasq)
CGroup: /system.slice/dnsmasq.service
|__ 39771 /usr/sbin/dnsmasq -k