31.6. DNS diagnostics, statistics and debug

31.6. DNS diagnostics, statistics and debug
	Chapter 31. DNS - Domain Name System

31.6.1. DNS diagnostics

This command reports the current situation of the DNS resource:

[17:49:20] ABILIS_CPX:d d dns

RES:Dns -----------------------------------------------------------------------
       Domain_Name_System                                                      
       STATE:READY     PRI-SERVER:008.008.008.008  SEC-SERVER:008.008.004.004
       ----------------|-- STATE --|--- CUR ---|-- PEAK ---|--- MAX ---|
       CACHE           |READY      |        140|        888|       5000|
       RELAY           |READY      |          0|        500|        500|
       RELAY-BLACKLIST |READY      |         33|          -|       2000|
       SERVER          |READY      |           |           |           |
       -----------------------------------------------------------------

The meaning:

STATE

The DNS driver state:

INACTIVE - State set when the configuration parameter ACT:NO and loaded by DNS driver.
ACTIVE - The driver is fully ready to work.

PRI-SERVER

Current DNS primary server IP address.

SEC-SERVER

Current DNS secondary server IP address.

CACHE-STATE

The DNS cache state:

INACTIVE - The parameter CACHE:NO and loaded by DNS driver, or when the parameter ACT:NO.
DOWN - Some internal errors which force CACHE service to be not operation are occurred.
READY - The DNS cache is activated and ready to work: (parameter CACHE:YES) and no errors with UDP service and ACT:YES.

RELAY-STATE

The DNS relay state:

INACTIVE - The parameter RELAY:NO and loaded by DNS driver, or when the parameter ACT:NO.
DOWN - Registration to lower UDP ports fail, better said when the "use" of UDP service is not possible.
READY - The DNS relay is fully ready to work: no errors with UDP service and ACT:YES.

RELAY-BLACKLIST

The DNS relay blacklist state:

INACTIVE - The parameter RELAY-BLACKLIST:NO and loaded by DNS driver, or when the parameter ACT:NO.
DOWN - Registration to lower UDP ports fail, better said when the "use" of UDP service is not possible.
READY - The DNS relay blacklist is fully ready to work: no errors with UDP service and ACT:YES.

SERVER-STATE

The DNS local server state:

INACTIVE - The parameter SERVER:NO and loaded by DNS driver, or when the parameter ACT:NO.
DOWN - Registration to lower UDP ports fail, better said when the "use" of UDP service is not possible.
READY - The DNS server is activated and ready to work: (parameter SERVER:YES) and no errors with UDP service and ACT:YES.

CACHE-CUR

Current number of used DNS cache entries.

CACHE-PEAK

The peak of used DNS cache entries.

CACHE-SIZE

Actual number of DNS cache entries available.

RELAY-CUR

RELAY records currently occupied with pending requests.

RELAY-PEAK

The peak of DNS relay requests.

RELAY-SIZE

Actual size of the requests' table.

RELAY-BLACKLIST-CUR

Currently banned domains.

RELAY-BLACKLIST-SIZE

Actual size of the relay-blacklist table.

31.6.2. DNS statistics

This command can help to understand what is happening, in case of troubles:

[11:42:10] ABILIS_CPX:d s dns

RES:Dns -----------------------------------------------------------------------
       Domain_Name_System                                                      
       --- Cleared 4 days 09:37:13 ago, on 28/09/2017 at 01:15:37 -------------
       - Resolver -------------------------------------------------------------
       -----------|---INPUT---|--OUTPUT---|-----------|---INPUT---|--OUTPUT---|
       PRI-QUERIES|           |         22|SEC-QUERIES|           |          6|
       PRI-RES    |         14|           |SEC-RES    |          0|           |
       PRI-UNK    |          0|           |SEC-UNK    |          0|           |
       PRI-RTY-OVR|          0|           |SEC-RTY-OVR|          0|           |
       PRI-TOUT   |          8|           |SEC-TOUT   |          6|           |
       PRI-ERRORS |          0|           |SEC-ERRORS |          0|           |
       ------------------------------------------------------------------------
       - Relay/Server ---------------------------------------------------------
       -----------|---INPUT---|--OUTPUT---|-----------|---INPUT---|--OUTPUT---|
       REQ-TOTAL  |       2571|           |PRI-REQ-RSP|       1940|       2475|
       REQ-SUCC   |       2013|           |SEC-REQ-RSP|          0|        558|
       REQ-BAD    |          0|           |PRI-NOMATCH|        535|           |
       OVERFLOW   |         23|           |SEC-NOMATCH|        535|           |
       DENIED-IP  |          0|           |RSP-BAD    |         13|           |
       ------------------------------------------------------------------------

With reference to the shown interval of time («Cleared 4 days 09:37:13 ago») these counters show the number of:

`PRI/SEC-QUERIES`	Queries for primary/secondary DNS server.
`PRI/SEC-RES`	Primary/Secondary resolved hostnames.
`PRI/SEC-UNK`	Primary/Secondary unknown host (answer received from server).
`PRI/SEC-RTY-OVR`	Primary/Secondary retransmission request without any answer from DNS server.
`PRI/SEC-TOUT`	Primary/Secondary timed-out server (answer was not received from server).
`PRI/SEC-ERRORS`	Primary/Secondary errors (e.g. Wrong datagram format).
`REQ-TOTAL`	All the clients' requests that arrived to DNS relay.
`REQ-SUCC`	Client's requests that were successfully processed.
`REQ-BAD`	Requests that was malformed or contained formal errors.
`OVERFLOW`	Client's requests that was discarded because the table was full.
`DENIED-IP`	DNS requests received from the clients but not processed because requester (the author of this DNS request) is not allowed. The not-allowed requester is a client whose IP address is not present in `IPSRC` and `IPSRCLIST` parameters configuration.
`PRI/SEC-REQ-RSP`	IN - responses from primary/secondary DNS that could be sent back to the client. OUT - requests sent to primary/secondary DNS server.
`PRI/SEC-NOMATCH`	Responses from primary/secondary DNS for which a matching request was not found in the table. A record in the table for a response could not found when: - DNS relay has not received a matching request for this response. - A record for this response was in the table but it became out of date and was used for other request.
`RSP-BAD`	Responses that had to be discarded because they had formal errors that prevents further processing.

31.6.3. DNS debug

Type the following command to view the commands allowed:

[15:03:49] ABILIS_CPX:debug res:dns

RES:Dns -----------------------------------------------------------------------
       Domain_Name_System                                                      
       BufferLength:64512  Date/Time:02/08/2016 15:03:53 TraceTime:99775682

Usage:
   LSN:0                = This help
   LSN:1                = Local statistics
   LSN:2 CMD:<name>     = Query: A (direct name lookup)
   LSN:3 CMD:<ipadd>    = Query: PTR (reverse ip lookup)
   LSN:4 CMD:<name>     = Query: MX (mail exchange)
   LSN:5 CMD:<ipadd>    = Query: MX (mail exchange)
   LSN:9                = Show DNS server's addresses

   LSN:20               = Load the blacklist from the file
   LSN:21               = Save the blacklist into the file
   LSN:22 CMD:<PAGE>    = Show the DNS blacklist table PAGE (1...9)
   LSN:23 CMD:<domain>  = Add the <domain> to the blacklist
   LSN:24 CMD:<domain>  = Remove the <domain> from the blacklist
   LSN:25 CMD:<FQDN>    = Test the FQDN against the blacklist
   LSN:29               = Print blacklist status

   LSN:40 CMD:<PAGE>    = Show the FQDN log table PAGE (1...9)
   LSN:41 CMD:<PAGE>    = Show the FQDN log table PAGE (1...9) with ageing order
   LSN:42 CMD:<PAGE>    = Show the FQDN log hash table PAGE (1...9)
   LSN:43 CMD:<FQDN>    = Add the <FQDN> to the log table
   LSN:47               = Clear FQDN log list
   LSN:48               = Show FQDN log statistics
   LSN:49               = Clear FQDN log statistics

	Note
	To use these commands you need to have administrator or super user rights.

Example: Type the following command to do a reverse IP lookup query.

[15:03:53] ABILIS_CPX:debug res:dns lsn:3 cmd:8.8.8.8

RES:Dns -----------------------------------------------------------------------
       Domain_Name_System                                                      
       BufferLength:64512  Date/Time:02/08/2016 15:05:09 TraceTime:99852319

Host: 8.8.8.8
Name: google-public-dns-a.google.com


31.5. DNS Blacklist (Web filter)		Chapter 32. DDNS - Dynamic DNS