Digi IX20 User Manual page 677

Services
d. Click  again to list additional IP addresses or networks.
n To limit access to specified IPv6 addresses and networks:
a. Click IPv6 Addresses.
b. For Add Address, click .
c. For Address, enter the IPv6 address or network that can access the device's DNS
d. Click  again to list additional IP addresses or networks.
n To limit access to hosts connected through a specified interface on the IX20 device:
a. Click Interfaces.
b. For Add Interface, click .
c. For Interface, select the appropriate interface from the dropdown.
d. Click  again to allow access through additional interfaces.
n To limit access based on firewall zones:
a. Click Zones.
b. For Add Zone, click .
c. For Zone, select the appropriate firewall zone from the dropdown.
d. Click  again to allow access through additional firewall zones.
5. (Optional) Cache negative responses is enabled by default. Disabling this option may improve
performance on networks with transient DNS results, when one or more DNS servers may have
positive results. To disable, click to toggle off Cache negative responses.
6. (Optional) Query all servers is enabled by default. This option is useful when only some DNS
servers will be able to resolve hostnames. To disable, click to toggle off Query all servers.
7. (Optional) Rebind protection, if enabled, prevents upstream DNS servers from returning
private IP addresses. To enable, click Rebind protection.
8. (Optional) Allow localhost rebinding is enabled by default if Rebind protection is enabled.
This is useful for Real-time Black List (RBL) servers.
9. (Optional) Type the IP address of the Fallback server. This is a DNS server to be used in the
absence of any other server. The default is 8.8.8.8.
10. (Optional) To add additional DNS servers:
a. Click DNS servers.
b. For Add Server, click .
c. (Optional) Enter a label for the DNS server.
d. For DNS server, enter the IP address of the DNS server.
IX20 User Guide
A single IP address or host name.
l
A network designation in CIDRnotation, for example, 192.168.1.0/24.
l
any: No limit to IPv4 addresses that can access the DNS service.
l
service. Allowed values are:
A single IP address or host name.
l
A network designation in CIDRnotation, for example, 2001:db8::/48.
l
any: No limit to IPv6 addresses that can access the DNS service.
l
See Firewall configuration for information about firewall zones.
Configure DNS
677