28.1. DNS Resource

The Abilis CPX DNS resource may behave as a DNS Resolver, as a DNS Relay or as a DNS Server too.

28.1.1. Activating the DNS resource

Add the resource to the Abilis system with the following command.

[12:18:28] ABILIS_CPX:a res:dns

RES:DNS ALREADY EXISTS

The DNS resource may already exist in the system, but may not yet be active: set it active with the command:

[12:18:31] ABILIS_CPX:s act res:dns

COMMAND EXECUTED
[Caution]Caution

After adding or setting the DNS active, you must restart the Abilis to make the resource running (use the command warm start to reboot the Abilis).

[17:14:59] ABILIS_CPX:s p dns act:yes

COMMAND EXECUTED

[17:15:17] ABILIS_CPX:d p dns

RES:Dns -----------------------------------------------------------------------
Run    DESCR:Domain_Name_System
       LOG:NO           ACT:YES 
       udp-locport:53   SRCADD:OUT-IP                      TOS:0-N      
       wdir:C:\APP\DNS\
       - Resolver -------------------------------------------------------------
       SERVERS:AUTO
       PRIMARY:#                 SECONDARY:#
       DELAY:5                   RTY:1                    
       CACHE:YES                 cache-size:500
       - Relay/Server ---------------------------------------------------------
       RELAY:NO                  relay-size:500            RELAY-TOUT:10  
       RELAY-BLACKLIST:YES       RELAY-BLACKLIST-BYPASS:#
       SERVER:NO
       IPSRC:*                   IPSRCLIST:#

28.1.2. DNS resource parameters

Use the following command to display the parameters of the resource; the command d p dns ? displays the meaning of all parameters.

[12:18:35] ABILIS_CPX:d p dns

RES:Dns -----------------------------------------------------------------------
Run    DESCR:Domain_Name_System
       LOG:NO           ACT:YES 
       udp-locport:53   SRCADD:OUT-IP                      TOS:0-N      
       wdir:C:\APP\DNS\
       - Resolver -------------------------------------------------------------
       SERVERS:AUTO
       PRIMARY:#                 SECONDARY:#
       DELAY:5                   RTY:1                    
       CACHE:YES                 cache-size:500
       - Relay/Server ---------------------------------------------------------
       RELAY:NO                  relay-size:500            RELAY-TOUT:10  
       RELAY-BLACKLIST:YES       RELAY-BLACKLIST-BYPASS:#
       SERVER:NO
       IPSRC:*                   IPSRCLIST:#

Meaning of the most important parameters:

LOG

Logging functionalities activation/deactivation.

ACT

Runtime DNS activation/deactivation.

SRCADD

Sets the IP address to be set in every outgoing DNS request.

TOS

Sets the TOS value for DNS service;

SERVERS

Servers IP resource [AUTO, Ip-nnn, STATIC], where 'nnn' is an IP resource index [1..250]. [AUTO: DNS resolver uses the servers retrieved by an IP resources that negotiates them e.g. IP-PPP. DNS: parameter of IP resources must be set to RETRIEVE, Ip-nnn: DSN resolver uses the available servers through Ip-nnn resource, STATIC: DNS resolver uses PRIMARY and SECONDARY servers].

PRIMARY

Sets the IP address of the primary DNS server, which the Abilis CPX resource refers to for name resolution.

SECONDARY

Sets the IP address of the secondary DNS server, which the Abilis CPX port refers to for name resolution.

DELAY

Sets the maximum time (in seconds) to wait for a response from the DNS server.

RTY

Sets how many times a request has to be sent to the DNS server if the DNS Resolver doesn't get any response in the expected time interval fixed in the DELAY parameter.

CACHE

Activates/deactivates the DNS cache.

cache-size

Sets the maximum size of the cache (expressed in bytes).

RELAY

Activates/deactivates the DNS Relay feature for DNS resource. DNS relay allows the relay of external DNS requests of DNS clients from CPX to DNS server.

relay-size

Sets the maximum size of the relay table (expressed in bytes).

RELAY-TOUT

Sets the time of life (in seconds) for a record in DNS relay table.

RELAY-BLACKLIST

Enable/disable DNS Relay blacklist service [NO, YES]

RELAY-BLACKLIST-BYPASS

List of IP adresses that bypass Relay blacklist service [ListName, #]

SERVER

Activates/deactivates the DNS Server feature for DNS resource.

IPSRC

Selects the IP address of the client from which the requests will be accepted.

IPSRCLIST

Sets the list of DNS Client systems enabled to use the DNS Relay or Server services.

The following command allows the administrator to change the configuration of the resource:

s p dns parameter:value...

[Caution]Caution

To activate the changes made on the upper case parameters, execute the initialization command init res:dns; while to set act the changes made on the lowercase parameters a save conf and an Abilis restart are required (i.e. with warm start command).