DNS Server Attributes

To configure attributes for the DNS servers that you want to use in the DNS ALG profile:

In Superuser mode, type configure terminal and press Enter.
```
ORACLE# configure terminal
```
Type media-manager and press Enter.
```
ORACLE(configure)# media-manager
```
Type dns-config and press Enter. The system prompt changes to let you know that you can begin configuring individual parameters.
```
ORACLE(media-manager)# dns-config
```
Type server-dns-attributes and then press Enter.
```
ORACLE(dns-config)# server-dns-attributes
```
From this point, you can configure DNS server parameters. To see all parameters for the DNS server, enter a ? at the system prompt.
server-realm—Enter the name of the realm in which the DNS server is located. This value is the name of a configured realm.
domain-suffix—Enter a list of one or more domain suffixes to indicate the domains you want to serve. These values are matched when a request is sent to a specific DNS server. If you leave this list empty (default), then your configuration will not work.
Note:
If you want to use a wildcard value, you can start your entry to an asterisk ( * ) (e.g. *.com). You can also start this value with a dot (e.g., .com).

To enter one address in this list, type client-address-list at the system prompt, a Space, the domain suffix, and then press Enter
```
ORACLE(server-dns-attributes)# domain-suffix acmepacket.com
```
To enter more than one address in this list, type domain-suffix at the system prompt, and a Space. Then type an open parenthesis ( ( ), each IPv4 address you want to use separated by a Space, and closed parenthesis ( ) ), and then press Enter.
```
ORACLE(server-dns-attributes)# domain-suffix (acmepacket.com acmepacket1.com acmepacket2.com)
```
server-address-list—Enter a list of one or more DNS IPv4 addresses for DNS servers. These DNS servers can be used for the domains you specified in the domain suffix parameter. Each domain can have several DNS servers associated with it, and so you can populate this list with multiple IPv4 addresses. If you leave this list empty (default), your configuration will not work.
source-address—Enter the IPv4 address for the DNS client interface on the Oracle® Enterprise Session Border Controller. If you leave this parameter empty (default), your configuration will not work.
source-port—Enter the number of the port for the DNS client interface on the Oracle® Enterprise Session Border Controller. The default value is 53. The valid range is:
- Minimum—1025
- Maximum—65535
transaction-timeout—Enter the time in seconds that the ALG should keep information to map a DNS server response back to the appropriate client request. After the transaction times out, further response to the original request will be discarded. The default value is 10. The valid range is:
- Minimum—0
- Maximum—999999999
address-translation—Enter a list of address translations that define the NAT function for the DNS servers.
You can access the NAT parameters for the DNS servers by typing address-translation and pressing enter within the DNS server attributes configuration.
```
ORACLE(dns-config)# server-dns-attributes
ORACLE(server-dns-attributes)# address-translation
```
To configure the NAT, enter two values:
- server-prefix: address/prefix that will be returned by the DNS server
- client-prefix: address/prefix that to which a response is returned
  
  Each of these is a two-part value:
- IPv4 address
- Number of bits indicating how much of the IPv4 address to match
  
  If you do not specify the number of bits, then all 32 bits of the IPv4 address will be used for matching. If you set the number of bits to 0, then the address will simply be copied.
  
  For example, if you set the server prefix to 10.3.17.2/16 and the client prefix to 192.168.0.0/16, then the Oracle® Enterprise Session Border Controller will return an address of 192.168.17.2 to the DNS client.
```
ORACLE(server-dns-attributes)# address-translation
ORACLE(address-translation)# server-prefix 10.3.17.2/16
ORACLE(address-translation)# client-prefix 192.168.0.0/16
```