Kerio Tech KERIO WINROUTE FIREWALL 6 User Manual download pdf (Page 107)

8.1 DNS module

107

Figure 8.2 Editor of the Hosts system ﬁle

Local DNS domain

In the When resolving name from the ’hosts’ ﬁle or lease table combine it with DNS domain

below entry, specify name of the local DNS domain.

If a host or a network device sends a request for an IP address, it uses the name only (it

has not found out the domain yet). Therefore, only host names without domain are saved

in the table of addresses leased by DHCP server . The DNS module needs to know the

name of the local domain to answer queries on fully qualiﬁed local DNS names (names

including the domain).

Note: If the local domain is speciﬁed in the DNS module, local names with or without the

domain can be recorded in the hosts system ﬁle.

The problem can be better understood through the following example.

Example

The local domain’s name is company.com. The host called john is conﬁgured so as to

obtain an IP address from the DHCP server. After the operating system is started the

host sends to the DHCP server a query with the information about its name (john). The

DHCP server assigns the host IP address 192.168.1.56. The DHCP server then keeps the

information that the IP address is assigned to the john host.

Another host that wants to start communication with the host will send a query on the

john.company.com name (the john host in the company.com domain). If the local do-

main name would not have been known by the DNS module, the forwarder would pass the

query to another DNS server as it would not recognize that it is a local host. However, as

DNS Forwarder knows the local domain name, the company.com name will be separated

and the john host with the appropriate IP address will be easily looked up in the DHCP

table.

1 2 ... 102 103 104 105 106 107 108 109 110 111 112 ... 367 368

No comments

Kerio Tech KERIO WINROUTE FIREWALL 6 User Manual Page 107