Use this window to create and configure a DNS (Domain Name System) group object. This object represents a DNS client on the SBC capable of communicating with external DNS servers to resolve domain names.
Note
Each signaling port within an Address Context must use a unique IP address and port number combination.
Note
The SBC 52x0 and SBC 7000 systems support creating IP Interface Groups containing sets of IP interfaces that are not "processor friendly" (i.e. carried on physical Ethernet ports served by separate processors). However, restrictions exist regarding the usage of such Interface Groups.
(This ability does not apply to the SBC 51x0 and SBC 5400 systems which have only two physical media ports. IP interfaces from the two physical ports may be configured within the same IP Interface Groups without restriction.)
For complete details, refer to Configuring IP Interface Groups and Interfaces.
Note
The SBC Core supports up to eight DNS servers per DNS group. The SBC 5xx0/5400/7000 platforms support up to 2,048 DNS Groups system-wide. The SBC SWe supports up to 128 DNS Groups. Refer to SBC Provisioning Limits for additional provisioning limitations.
To View DNS Groups
On the SBC main screen, go to Configuration > System Provisioning > Category: Base Provisioning > DNS > Servers > DNS > DNS Group or
All > Address Context > DNS Group
The DNS Group window is displayed. Select an Address Context to display only the DNS Groups configured within the selected Address Context.
DNS Group
To Create a DNS Group
To create a new DNS Group:
In the DNS Group window, select the Address Context within which you want to create the DNS Group.
Click New DNS Group. The Create New DNS Group window is displayed.
Create New DNS Group Window
- Use the following table to configure the options and then click Save.
DNS Group Parameters
Parameter | Description |
|---|---|
Name | Specify the name for the DNS Group of upto 23 characters. This field is mandatory. |
Type | Specify the interface type to use for DNS queries. The options are:
Based on the type chosen, the additional options open. |
Transport | Select the transport protocol to communicate with the DNS servers.
|
Mgmt Interface | Select the management interface group for the management interfaces. Note: This field displays only when the selected Type is Mgmt. |
IP Interface | Select the IP interface group for the packet interfaces. Note: This field displays when the selected Type is IP. |
Use Configured Dns Server | When this flag is disabled, the SBC stores "Authoritative" NS records received in Domain Name System (DNS) query responses and uses them to locate a closer DNS server for subsequent DNS queries. There are cases where an “Authoritative” server might not be directly reachable from the SBC, or IP ACL rules ( configured on the SBC) blocks its query responses. This block causes the DNS queries to fail and subsequent call failures. When this flag is enabled, the SBC supports using the configured DNS for external the DNS queries within that DNS group. It sends the DNS queries to the DNS server in the DNS group and ignores Authoritative servers.The options are:
|
Edns Support | Enable this flag to support Extension mechanisms for Domain Name Systems (EDNS) for statically configured and dynamically learned DNS servers. The options are:
|
| Rcode Error Monitor Timer | Configure the RCODE error monitor timer interval to allow the SBC to monitor RCODE errors. When the timer value is 0, this feature is disabled. Range: 0 - 60 minutes Default: 0 minutes |
To Edit a DNS Group
To edit a DNS Group object:
- Click the option button next to the DNS Group you want to edit. The Edit DNS Group window opens.
- Modify the options as needed and click Save.
To Delete a DNS Group
To delete a DNS Group:
- Click the option button next to the DNS Group that you want to delete.
- Click the Delete icon at the end of the highlighted row.
- Confirm the deletion when prompted.
Note
Before deleting a DNS group, first delete the DNS local records and DNS servers in that group.
DNS Group Commands
Use DNS Group commands to perform manual actions against a configured DNS Group.
To use DNS Group commands for any specific DNS Group, select the option next to the specific DNS Group. The DNS Group Commands window is displayed at the bottom of the window.
DNS Group Commands
Clear Cache
Use the Clear Cache command to clear the cache of a specified record.
Choose Clear Cache in the Commands list and click Select. A clearCache dialog box opens.
Clear Cache
- In Domain Name text box, enter the name of the domain record you want to clear from the cache.
- In Record Type drop-down, select the type of DNS record to clear. The options are:
- A
- Aaaa
- Ns
- Srv
- Naptr
- Default (default)
- Click clearCache.
DNS Server Reset
Use the DNS Server Reset command to reset all the DNS server statistics.
- Choose DNS Server Reset in the Commands list and click Select. A dnsServerReset dialog box opens.
- Click dnsServeReset.
- Confirm the action at the prompt.
Query
Use the Query command to send a DNS query to a specified server.
Choose Query in the Commands list and click Select. A query dialog box is displayed.
Query Command
- Use the following table to enter parameters for the query and click query.
Query Parameters
| Parameter | Description |
|---|---|
| DNS Server | Enter the name of the DNS Server to perform lookup. |
| FQDN | Enter the domain to perform look up. |
| Record Type | Specifies the type of DNS records.
|
Update Ttl
Use the Update Ttl command to to update the TTL (Time To LIve) value in the cache for a specified record.
Choose Update Ttl in the Commands list and click Select. An update Ttl dialog box is displayed.
Update Ttl Command
- Use the following table to select the record to update and click updateTtl.
Update Ttl Parameters
| Parameter | Description |
|---|---|
| FQDN | Enter the FQDN whose record to update in the cache. |
| Record Type | Specifies the type of DNS records.
|
| Ttl | Enter a new TTL value. |
Overview
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