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This object creates and configures a DNS group object, 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 5000/7000 series platforms support up to 2,048 DNS Groups system-wide. SBC SWe supports up to 128 DNS Groups. See SBC Provisioning Limits for additional provisioning limitations. 

To View DNS Group

On the SBC main screen, go to Configuration > System Provisioning > Category: Base Provisioning > DNS > DNS Group. The DNS Group window is displayed.

DNS Group

 

To Edit DNS Group

To edit any of the DNS Groups in the list, click the radio button next to the specific DNS Group name.

DNS - DNS Group Highlighted

 

 

The Edit Selected DNS Group window is displayed below.

DNS - DNS Group Edit

 

Make the required changes and click Save at the right hand bottom of the panel to save the changes made.

To Create DNS Group

To create a new DNS Group, click New DNS Group tab on the DNS Group List panel.

DNS - DNS Group Fields

 

The Create New DNS Group window is displayed.

DNS - DNS Group Create

 

The following fields are displayed:

DNS Group Parameters

 

Parameter

Description

Name

Name of the DNS Group. Must be 1-23 characters. This field is mandatory.

Type

Specifies the Interface type. Based on the type, the following Interface will be displayed:

  • IP—IP interface group name.

  • Mgmt— Management Interface group Name.

  • None (default)

Transport

The transport protocol to use to communicate with DNS servers.

  • UDP (default)

  • TCP 

Mgmt Interface

Specifies the management interface group name.

Note

This field appears only when Type field is selected as Mgmt.

IP Interface

Specifies the IP interface group name.

Note

This field appears only when Type field is selected as IP.

Use Configured DNS Server

With the option disabled, the SBC stores "Authoritative" NS records received in Domain Name System (DNS) query responses and uses them for locating a closer DNS server for subsequent DNS queries. There are cases where an “Authoritative” server may not be directly reachable from the SBC, or its query responses are blocked by IP ACL rules configured on the SBC. This causes DNS queries to fail and subsequent call failures. With the option enabled, the SBC supports using the configured DNS for external 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:

  • Disabled (default)

  • Enabled

EDNS Support

Enable flag to support Extension mechanisms for Domain Name Systems (EDNS) for statically configured and dynamically learned DNS servers. The options are:

  • Disabled (default) 

  • Enabled 

To Delete DNS Group

To delete any of the created DNS Groups, click the radio button next to the specific DNS Group which you want to delete.

DNS - DNS Group Highlighted

 

 

Click Delete at the end of the highlighted row. A delete confirmation message appears seeking your decision.

DNS Group Delete Confirmation

 

Click Yes to remove the specific DNS Group from the list.

Note

Before deleting a DNS group, first delete the DNS local record names and DNS server in that group.

DNS Group Commands

To view the DNS Group Commands for any specific DNS Group, click the radio button next to the specific DNS Group to highlight the row.

DNS - DNS Group Highlighted

 

 

The DNS Group Commands window is displayed at the bottom of the screen.

Dns Group Admin Commands

 

The option displayed is:

  • Clear Cache: Clears the cache of matching records.
  • DNS Server Reset: Resets all the DNS server statistics.
  • Query: Performs the DNS query to the server.
  • Update Ttl: Updates the Cache of the matching record with the new TTL value.

Clear Cache

Choose Clear Cache to clear the cache and click Select.

A dialogue box appears seeking your confirmation to execute.

Clear Cache

 

The following fields are displayed:

Clear Cache Parameters

 
ParameterDescription
Domain NameEnter domain to be cleared.
Record Type

Specifies whether to use the DNS server for just A-record lookups or for full NAPTR/SRV/A lookup as specified in RFC3263. The options are:

  • A
  • Aaaa
  • Ns
  • Srv
  • Naptr
  • Default (default)

Make the required changes and click clearCache button to confirm. The result of the action is displayed.

Click OK to complete.

DNS Server Reset

Choose DNS Server Reset to reset all the DNS servers and click Select.

A pop window appears seeking your confirmation to execute.

Dns Group Commands pop-up

 

Click DNS Server Reset button to confirm. The result of the action is displayed.

Click OK to complete.

Query

Choose Query to query a DNS server and click Select.

A pop window appears seeking your confirmation to execute.

Query Command

 

The following fields are displayed:

Query Parameters

 
ParameterDescription
DNS ServerEnter a DNS Server to be used to perform lookup.
FQDNEnter domain to be looked up.
Record Type

Specifies whether to use the DNS server for just A-record lookups, or for full NAPTR/SRV/A lookup as specified in RFC3263.

  • A (default)
  • Aaaa
  • Ns
  • Srv
  • Naptr

Make the required changes and click query button to confirm. The result of the action is displayed.

Click OK to complete.

Updated Ttl

Choose Updated Ttl to update the cache of the matching record with the new TTL value and click Select.

A pop window appears seeking your confirmation to execute.

Updated Ttl Command

 

The following fields are displayed:

Updated Ttl Parameters

 
ParameterDescription
FQDNEnter FQDN to be updated from the Cache..
Record Type

Specifies whether to use the DNS server for just A-record lookups, or for full NAPTR/SRV/A lookup as specified in RFC3263.

  • A (default)
  • Aaaa
  • Ns
  • Srv
  • Naptr
  • Default
TtlEnter new TTL value.

Make the required changes and click Updated Ttl button to confirm. The result of the action is displayed.

Click OK to complete.

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