Kerio Tech KERIO WINROUTE FIREWALL 6 User Manual
Page 120
Chapter 8
Configuration of network services
120
•
free — user can choose from several second level domains (e.g.
no-ip.org
,
ddns.info
,
etc.)
and
select
a
free
host
name
for
the
domain
(e.g.
company.ddns.info
).
•
paid service — user registers their own domain (e.g. company.com) and the service
provider then provides DNS server for this domain with the option of automatic up-
date of records.
User of the service gets an account which is used for access authentication (this will guarantee
that only authorized users can update DNS records. Update is performed via secured connec-
tion (typically HTTPS) to make sure that the traffic cannot be tapped. Dynamic DNS records
can be updated either manually by the user or (mostly) by a specialized software — WinRoute
in this case.
If WinRoute enables cooperation with dynamic DNS, a request for update of the IP address
in dynamic DNS is sent upon any change of the Internet interface’s IP address (including
switching between primary and secondary Internet connection — see chapter
). This keeps
DNS record for the particular IP address up-to-date and mapped services may be accessed by
the corresponding host name.
Note:
1.
Usage of DDNS follows conditions of the particular provider.
2.
Dynamic DNS records use very short time-to-live (TTL) and, therefore, they are kept in
cache of other DNS servers or forwarders for a very short time. Probability that the client
receives DNS response with an invalid (old) IP address is, therefore, very low.
3.
Some DDNS servers also allow concurrent update of more records. Wildcards are used for
this purpose.
Example: In DDNS there exist two host names, both linked to the public IP address of
the firewall: fw.company.com and server.company.com. If the IP address is changed,
it is therefore possible to send a single request for update of DNS records with name
*.company.com. This requests starts update of DNS records of both names.
DDNS configuration in WinRoute
To set cooperation with the dynamic DNS server, go to the Dynamic DNS folder in Configura-
tion → Advanced Options.
As already mentioned, the first step is to make an account (i.e. required dynamic DNS record
with appropriate access rights) at a DDNS provider. WinRoute now supports these DDNS
providers:
•
ChangeIP
),
•
DynDNS
•
No-IP
).