Figure 2-61. Change Primary Dns Ip Address Screen - Siemens A53457 Installation & Maintenance

If either server provides an IP address, that IP address is used for the Domain One, Domain Two,
or Default Gateway as needed. If neither DNS knows the IP address for the symbolic names, the IP
addresses for Domain One, Domain Two, and/or the Default Gateway -- if they used symbolic
names -- will remain unresolved and the OSI system will not operate at all.
In the event an Active Route expires (gets moved to the Pending list and then expires), the WAG
will discard all of its resolved IP addresses and the symbolic names are once again sent through
the look-up process to resolve their IP addresses.
This is very important because disaster recovery factors into this behavior. In the event links to
office devices break and are expired, a user may configure a new IP address into one or both of
the DNS servers, pointing the office machines to another geographical location somewhere on the
Network.
Because of that disaster recovery process, the WAG is required to detect the loss of the office
links (by timing out the Active, then Pending routes) and then discarding the resolved IP addresses
which may or may not be valid any longer.
Then the WAG, after discarding the old resolved IP addresses, will again ask the DNS servers what
the IP addresses are for the symbolic names. In the event a user reconfigured the IP address for
the symbolic names in the DNS servers, the servers will inform the WAG of what the new IP
addresses are.
This means that if there are a hundred WAGs in the network and an office facility is destroyed or
loses power, the WAGs do not need to be reconfigured. Only the DNS server configuration needs
to be reconfigured and all WAGs will eventually ask the DNS server what the new IP address is for
the symbolic names.
These Primary and Secondary DNS values default to: Disabled
To change the Primary DNS IP Address:
1. On the Second Configuration Menu, select "Primary DNS" IP Address to be changed. The
Change Primary DNS IP Address screen appears.

Figure 2-61. Change Primary DNS IP Address Screen

2. From the screen in figure 2-61, do one of the following:
a. To disable the Primary DNS IP Address enter 0 (zero) in the first data field and then press
ENTER. The user will be returned to the Second Configuration Menu. Go to step 3.
Document No.: COM-00-05-16
Version: C.1
INSTALLATION AND CONFIGURATION
2-45
June 2006, Revised June 2014