Provided by: oarc-dsc_2.15.2-3_amd64 
NAME
dsc.conf - Configuration for the DNS Statistics Collector
DESCRIPTION
The file dsc.conf contains defaults for the program dsc(1) . Each line is a configuration option and may
have arguments in the form option value;. Comment lines must have a hash sign (#) in the first column.
Since dsc(1) version 2.2.0, a configuration line may not be divided with CR/LF and quoted characters are
not understood (\quote).
CONFIGURATION
local_address IP [ MASK / BITS ] ;
Specifies the DNS server's local IP address with an optional mask/bits for local networks. It is
used to determine the direction of an IP packet: sending, receiving, or other. You may specify
multiple local addresses by repeating the local_address line any number of times.
run_dir PATH ;
A directory that will become dsc current directory after it starts. Output files will be written
here, as will any core dumps.
minfree_bytes BYTES ;
If the filesystem where dsc writes its output files does not have at least this much free space,
then dsc will not write the files. This prevents dsc from filling up the filesystem. The files
that would have been written are simply lost and cannot be recovered. Output files will be
written again when the filesystem has the necessary free space.
pid_file " FILE " ;
The file where dsc will store its process id.
bpf_program " RULE " ;
A Berkeley Packet Filter program string. You may use this to further restrict the traffic seen
but note that dsc currently has one indexer that looks at all IP packets. If you specify
something like udp port 53 that indexer will not work.
However, if you want to monitor multiple DNS servers with separate dsc instances on one collector
box, then you may need to use bpf_program to make sure that each dsc process sees only the traffic
it should see.
Note that this directive must go before the interface directive because dsc makes only one pass
through the configuration file and the BPF filter is set when the interface is initialized.
dns_port NUMBER ;
dsc will only parse traffic coming to or leaving the DNS port (default 53), this option lets you
control which port that is in case it's not standard.
pcap_buffer_size NUMBER ;
Set the buffer size (in bytes) for pcap, increasing this may help if you see dropped packets by
the kernel but increasing it too much may have other side effects.
Note that this directive must go before the interface directive because dsc makes only one pass
through the configuration file and the pcap buffer size is set when the interface is initialized.
pcap_thread_timeout MILLISECONDS ;
Set the internal timeout pcap-thread uses when waiting for packets, the default is 100 ms.
Note that this directive must go before the interface directive.
drop_ip_fragments ;
Drop all packets that are fragments.
Note that this directive must go before the interface directive.
interface IFACE | FILE ;
The interface name to sniff packets from or a pcap file to read packets from. You may specify
multiple interfaces by repeating the interface line any number of times.
Under Linux (kernel v2.2+) libpcap can use an "any" interface which will include any interfaces
the host has but these interfaces will not be put into promiscuous mode which may prevent
capturing traffic that is not directly related to the host.
dnstap_file FILE ;
dnstap_unixsock FILE [ USER ][ :GROUP ] [ UMASK ] ;
dnstap_tcp IP PORT ;
dnstap_udp IP PORT ;
Specify DNSTAP input from a file, UNIX socket, UDP or TCP connections (dsc will listen for
incoming connections). This type of input is delivered directly from the DNS software itself as
encapsulated DNS packets as seen or as made by the software. See https://dnstap.info for more
information about DNSTAP.
For UNIX sockets there are additional optional options to control access to it. The user and
group access are specified together as strings (USER:GROUP), separated with a colon if a group is
specified. The file permissions are controlled by a file mode creation mask (UMASK, must being
with 0) which is set temporarily during socket creation. It is not necessary to specify all
options, you can specify only USER, only :GROUP or only UMASK.
Example below shows how to give read and write access to somegroup, remove permissions for others
and how the resulting socket file permissions would be:
dnstap_unixsock /path/to/file.sock :somegroup 0007;
srwxrwx--- 1 root somegroup 0 Date dd HH:MM /path/to/file.sock
NOTE:
- Only one DNSTAP input can be specified at a time currently.
- Configuration needs to match that of the DNS software.
dnstap_network IPV4 IPV6 PORT ;
Specify DNSTAP network information.
Per DNSTAP specification, some information may be not included such as receiver or sender of DNS.
To be able to produce statistics, dsc needs to know what to put in place when that information is
missing. This is configured by dnstap_network and should be the primary IP addresses and port of
the DNS software.
Default values are 127.0.0.1 ::1 53.
qname_filter NAME FILTER ;
This directive allows you to define custom filters to match query names in DNS messages. Please
see section QNAME FILTERS for more information.
datasets NAME TYPE LABEL:FIRST LABEL:SECOND FILTERS [ PARAMETERS ] ;
This directive is the heart of dsc. However, it is also the most complex (see section DATASETS).
See section EXAMPLE for a set of defined good datasets which is also installed as dsc.conf.sample.
bpf_vlan_tag_byte_order TYPE ;
dsc knows about VLAN tags. Some operating systems (FreeBSD-4.x) have a bug whereby the VLAN tag
id is byte-swapped. Valid values for this directive are host and net (the default). Set this to
host if you suspect your operating system has the VLAN tag byte order bug.
match_vlan ID [ ID ... ] ;
A white-space separated list of VLAN identifiers. If set, only the packets belonging to these
VLANs are analyzed.
statistics_interval SECONDS ;
Specify how often dsc should write statistics, default to 60 seconds.
no_wait_interval ;
Do not wait on interval sync to start capturing, normally DSC will sleep for time() %
statistics_interval to align with the minute (as was the default interval before) but now if you
change the interval to more then a minute you can use with option to begin capture right away.
output_format FORMAT ;
Specify the output format. You may specify multiple formats by repeating the output_format line
any number of times. Default output format is XML, see section DATA FORMATS and FILE NAMING
CONVENTIONS.
output_user USER ;
Specify which user should own the output file, default to the user running dsc.
output_group GROUP ;
Specify which group should own the output file, default to the group of the user running dsc.
output_mod FILE_MODE_BITS ;
Specify the file mode bits (in octal) for the output file permissions, default to 0664.
dump_reports_on_exit ;
Dump any remaining report before exiting.
NOTE: Timing in the data files will be off!
geoip_v4_dat " FILE " [ OPTION ... ] ;
Specify the GeoIP dat file to open for IPv4 country lookup, see section GEOIP for options.
geoip_v6_dat " FILE " [ OPTION ... ] ;
Specify the GeoIP dat file to open for IPv6 country lookup, see section GEOIP for options.
geoip_asn_v4_dat " FILE " [ OPTION ... ] ;
Specify the GeoIP dat file to open for IPv4 AS number lookup, see section GEOIP for options.
geoip_asn_v6_dat " FILE " [ OPTION ... ] ;
Specify the GeoIP dat file to open for IPv6 AS number lookup, see section GEOIP for options.
asn_indexer_backend BACKEND ;
Specify what backend to use for the ASN indexer, either "geoip" for GeoIP Legacy or "maxminddb"
for MaxMind DB (GeoIP2).
country_indexer_backend BACKEND ;
Specify what backend to use for the country indexer, either "geoip" for GeoIP Legacy or
"maxminddb" for MaxMind DB (GeoIP2).
maxminddb_asn " FILE " ;
Specify the MaxMind DB file to use for ASN lookups.
maxminddb_country " FILE " ;
Specify the MaxMind DB file to use for country lookups.
client_v4_mask NETMASK ;
Set the IPv4 MASK for client_subnet INDEXERS.
client_v6_mask NETMASK ;
Set the IPv6 MASK for client_subnet INDEXERS.
response_time_mode MODE ;
Set the output MODE of the response time indexer:
bucket Count response time in buckets of microseconds, see response_time_bucket_size for setting
the size of the buckets.
log10 Count response time in logarithmic scale with base 10.
log2 Count response time in logarithmic scale with base 2.
response_time_max_queries NUMBER ;
Set the maximum number of queries to keep track of.
response_time_full_mode MODE ;
If the number of queries tracked exceeds response_time_max_queries the MODE will control how to
handle it:
drop_query
Drop the incoming query.
drop_oldest
Drop the oldest query being tracked and accept the incoming one.
response_time_max_seconds SECONDS ;
Set the maximum seconds to keep a query but a query can still be matched to a response while being
outside this limit, see response_time_max_sec_mode on how to handle those situations.
response_time_max_sec_mode MODE ;
Control how to handle queries and responses which are match successfully but exceeds
response_time_max_seconds:
ceil The query will be counted as successful but the time it took will be the maximum seconds
(think ceiling, or ceil()).
timed_out
The query will be counted as timed out.
response_time_bucket_size SIZE ;
Control the size of bucket (microseconds) in bucket mode.
knowntlds_file FILE ;
Load known TLDs from FILE, this should be or have the same format as
https://data.iana.org/TLD/tlds-alpha-by-domain.txt.
tld_list FILE ;
This option changes what DSC considers a TLD (similar to Public Suffix List) and affects any
indexers that gathers statistics on TLDs, such as the tld, second_ld and third_ld indexers. The
file format is simply one line per suffix and supports commenting out lines with #. You can use
dsc-psl-convert to convert the Public Suffix List to this format, see dsc-psl-convert(5) for more
information and examples on how to setup.
DATASETS
A dataset is a 2-D array of counters. For example, you might have a dataset with “Query Type” along one
dimension and “Query Name Length” on the other. The result is a table that shows the distribution of
query name lengths for each query type.
A dataset has the following format:
datasets NAME TYPE LABEL:FIRST LABEL:SECOND FILTERS [ PARAMETERS ] ;
NAME The name of the dataset, this must be unique and is used in the filename for the output files.
TYPE The protocol layer, available layers are:
ip
dns
LABEL The label of the dimensions.
FIRST The indexer for the first dimension, see INDEXERS sections.
SECOND The indexer for the second dimension, see INDEXERS sections.
FILTERS
One or more filters, see FILTERS sections.
PARAMETERS
Zero or more parameters, see section PARAMETERS.
INDEXERS AND FILTERS
An indexer is simply a function that transforms the attributes of an IP/DNS message into an array index.
For some attributes the transformation is straightforward. For example, the “Query Type” indexer simply
extracts the query type value from a DNS message and uses this 16-bit value as the array index.
Other attributes are slightly more complicated. For example, the “TLD” indexer extracts the TLD of the
QNAME field of a DNS message and maps it to an integer. The indexer maintains a simple internal table of
TLD-to-integer mappings. The actual integer values are unimportant because the TLD strings, not the
integers, appear in the resulting data.
When you specify an indexer on a dataset line, you must provide both the name of the indexer and a label.
The Label appears as an attribute in the output.
For example the following line:
dataset the_dataset dns Foo:foo Bar:bar queries-only;
Would produce the following XML output:
<array name="the_dataset" dimensions="2" start_time="1091663940" ...
<dimension number="1" type="Foo"/>
<dimension number="2" type="Bar"/>
<data>
<Foo val="1">
<Bar val="0" count="4"/>
...
<Bar val="100" count="41"/>
</Foo>
<Foo val="2">
...
</Foo>
</data>
</array>
IP INDEXERS
dsc includes only minimal support for collecting IP-layer stats. Mostly we are interested in finding out
the mix of IP protocols received by the DNS server. It can also show us if/when the DNS server is the
subject of denial-of-service attack.
ip_direction
One of three values: sent, recv or else. Direction is determined based on the setting for
local_address in the configuration file.
ip_proto
The IP protocol type, e.g.: tcp, udp or icmp. Note that the bpf_program setting affects all
traffic seen. If the program contains the word “udp” then you won't see any counts for non-UDP
traffic.
ip_version
The IP version number, e.g.: 4 or 6. Can be used to compare how much traffic comes in via IPv6
compared to IPv4.
IP FILTERS
Currently there is only one IP protocol filter: any. It includes all received packets.
DNS INDEXERS
certain_qnames
This indexer isolates the two most popular query names seen by DNS root servers: localhost and
[a--m].root-servers.net.
client_subnet
Groups DNS messages together by the subnet of the client's IP address. The subnet is masked by
/24 for IPv4 and by /96 for IPv6. We use this to make datasets with large, diverse client
populations more manageable and to provide a small amount of privacy and anonymization.
client The IP (v4 and v6) address of the DNS client.
server The IP (v4 and v6) address of the DNS server.
country
The country code of the IP (v4 and v6), see section GEOIP.
asn The AS (autonomous system) number of the IP (v4 and v6), see section GEOIP.
do_bit This indexer has only two values: 0 or 1. It indicates whether or not the “DO” bit is set in a
DNS query. According to RFC 2335: Setting the DO bit to one in a query indicates to the server
that the resolver is able to accept DNSSEC security RRs.
edns_version
The EDNS version number, if any, in a DNS query. EDNS Version 0 is documented in RFC 2671.
edns_bufsiz
The EDNS buffer size per 512 chunks (0-511, 512-1023 etc).
edns_cookie
Indicates whether or not a EDNS(0) Cookie (RFC7873) was present with "yes" or "no".
edns_cookie_len
The combined length of the EDNS(0) client and server cookies.
edns_cookie_client
The EDNS(0) Client Cookie bytes as a hexadecimal string.
edns_cookie_server
The EDNS(0) Server Cookie bytes as a hexadecimal string.
edns_ecs
Indicates whether or not a EDNS(0) Client Subnet (RFC7871) was present with "yes" or "no".
edns_ecs_family
The EDNS(0) Client Subnet address family.
edns_ecs_source_prefix
The EDNS(0) Client Subnet source prefix-length.
edns_ecs_scope_prefix
The EDNS(0) Client Subnet scope prefix-length.
edns_ecs_address
The EDNS(0) Client Subnet address bytes as a hexadecimal string.
edns_ecs_subnet
The EDNS(0) Client Subnet address as an IPv4/IPv6 textual address.
edns_ede
Indicates whether or not a EDNS(0) Extended DNS Errors (RFC8914) was present with "yes" or "no".
edns_ede_code
The EDNS(0) Extended DNS Errors code.
edns_ede_textlen
The length of the EDNS(0) Extended DNS Errors extra-text.
edns_ede_text
The EDNS(0) Extended DNS Errors extra-text.
edns_nsid
Indicates whether or not a EDNS(0) DNS Name Server Identifier (RFC5001) was present with "yes" or
"no".
edns_nsid_len
The length of the EDNS(0) DNS Name Server Identifier (NSID).
edns_nsid_data
The EDNS(0) DNS Name Server Identifier (NSID) bytes as a hexadecimal string.
edns_nsid_text
The EDNS(0) DNS Name Server Identifier (NSID) as a string of printable characters. Unprintable
characters are replaced with ".".
idn_qname
This indexer has only two values: 0 or 1. It returns 1 when the first QNAME in the DNS message
question section is an internationalized domain name (i.e., containing non-ASCII characters).
Such QNAMEs begin with the string xn--. This convention is documented in RFC 3490.
msglen The overall length (size) of the DNS message.
null A “no-op” indexer that always returns the same value. This can be used to effectively turn the
2-D table into a 1-D array.
opcode The DNS message opcode is a four-bit field. QUERY is the most common opcode. Additional
currently defined opcodes include: IQUERY, STATUS, NOTIFY, and UPDATE.
qclass The DNS message query class (QCLASS) is a 16-bit value. IN is the most common query class.
Additional currently defined query class values include: CHAOS, HS, NONE, and ANY.
qname The full QNAME string from the first (and usually only) QNAME in the question section of a DNS
message.
qnamelen
The length of the first (and usually only) QNAME in a DNS message question section. Note this is
the “expanded” length if the message happens to take advantage of DNS message “compression”.
label_count
The number of labels (between "." dots) in the first (and usually only) QNAME in a DNS message
question section. Note that a value of 0 (zero) means DNS root (.).
qtype The query type (QTYPE) for the first QNAME in the DNS message question section. Well-known query
types include: A, AAAA, A6, CNAME, PTR, MX, NS, SOA, and ANY.
query_classification
A stateless classification of “bogus” queries:
non-auth-tld
When the TLD is not one of the IANA-approved TLDs.
root-servers.net
A query for a root server IP address.
localhost
A query for the localhost IP address.
a-for-root
An “A” query for the DNS root (.).
a-for-a
An “A” query for an IPv4 address.
rfc1918-ptr
A PTR query for an RFC 1918 address.
funny-class
A query with an unknown/undefined query class.
funny-qtype
A query with an unknown/undefined query type.
src-port-zero
When the UDP message's source port equals zero.
malformed
A malformed DNS message that could not be entirely parsed.
rcode The RCODE value in a DNS response. The most common response codes are 0 (NO ERROR) and 3
(NXDOMAIN).
rd_bit This indexer returns 1 if the RD (recursion desired) bit is set in the query. Usually only stub
resolvers set the RD bit. Usually authoritative servers do not offer recursion to their clients.
tc_bit This indexer returns 1 if the TC (truncated) bit is set (in a response). An authoritative server
sets the TC bit when the entire response won't fit into a UDP message.
tld The TLD of the first QNAME in a DNS message's question section.
second_ld
The Second LD of the first QNAME in a DNS message's question section.
third_ld
The Third LD of the first QNAME in a DNS message's question section.
transport
Indicates whether the DNS message is carried via UDP or TCP.
dns_ip_version
The IP version number that carried the DNS message.
dns_source_port
The source port of the DNS message.
dns_sport_range
The source port of the DNS message per 1024 chunks (0-1023, 1024-2047 etc).
qr_aa_bits
The "qr_aa_bits" dataset may be useful when dsc is monitoring an authoritative name server. This
dataset counts the number of DNS messages received with each combination of QR,AA bits. Normally
the authoritative name server should *receive* only *queries*. If the name server is the target
of a DNS reflection attack, it will probably receive DNS *responses* which have the QR bit set.
response_time
An indexer to track queries and return the response time in buckets along with other state buckets
for timeouts, missing queries (received a response but have never seen the query), dropped queries
(due to memory limitations) and internal errors. Queries are matched against responses by
checking (in this order) the DNS ID, the IP version and protocol, client IP, client port, server
IP and last server port. There are a few configuration options to control how response time
statistics are gathered and handled, please see CONFIGURATION. NOTE: Only one instance of this
indexer can be used in a dataset, this is due to the state to stores and the design of DSC.
encryption
Indicates whether the DNS message was carried over an encrypted connection or not, and if so over
which. For example "unencrypted", "dot" (DNS-over-TLS), "doh" (DNS-over-HTTPS). This information
is only available via DNSTAP and if supported by the software generating it.
DNS FILTERS
You must specify one or more of the following filters (separated by commas) on the dataset line. Note
that multiple filters are ANDed together. That is, they narrow the input stream, rather than broaden it.
any The no-op filter, counts all messages.
queries-only
Count only DNS query messages. A query is a DNS message where the QR bit is set to 0.
replies-only
Count only DNS response messages. A response is a DNS message where the QR bit is set to 1.
nxdomains-only
Count only NXDOMAIN responses.
popular-qtypes
Count only DNS messages where the query type is one of: A, NS, CNAME, SOA, PTR, MX, AAAA, A6, ANY.
idn-only
Count only DNS messages where the query name is in the internationalized domain name format.
aaaa-or-a6-only
Count only DNS messages where the query type is AAAA or A6.
root-servers-net-only
Count only DNS messages where the query name is within the root-servers.net domain.
chaos-class
Counts only DNS messages where QCLASS is equal to CHAOS (3). The CHAOS class is generally used
for only the special hostname.bind and version.bind queries.
priming-query
Count only DNS messages where the query type is NS and QNAME is “.”.
servfail-only
Count only SERVFAIL responses.
authentic-data-only
Count only DNS messages with the AD bit is set.
edns0-only
Count only DNS messages with EDNS(0) options.
edns0-cookie-only
Count only DNS messages with EDNS(0) Cookie option.
edns0-nsid-only
Count only DNS messages with EDNS(0) DNS Name Server Identifier option.
edns0-ede-only
Count only DNS messages with EDNS(0) Extended DNS Errors option.
edns0-ecs-only
Count only DNS messages with EDNS(0) Client Subnet option.
QNAME FILTERS
Defines a custom QNAME-based filter for DNS messages. If you refer to this named filter on a dataset
line, then only queries or replies for matching QNAMEs will be counted. The QNAME argument is a regular
expression. For example:
qname_filter WWW-Only ^www. ;
dataset qtype dns All:null Qtype:qtype queries-only,WWW-Only ;
PARAMETERS
dsc currently supports the following optional parameters:
min-count=NN
Cells with counts less than NN are not included in the output. Instead, they are aggregated into
the special values -:SKIPPED:- and -:SKIPPED_SUM:-. This helps reduce the size of datasets with a
large number of small counts.
max-cells=NN
A different, perhaps better, way of limiting the size of a dataset. Instead of trying to
determine an appropriate min-count value in advance, max-cells allows you put a limit on the
number of cells to include for the second dataset dimension. If the dataset has 9 possible first-
dimension values, and you specify a max-cell count of 100, then the dataset will not have more
than 900 total values. The cell values are sorted and the top max-cell values are output. Values
that fall below the limit are aggregated into the special -:SKIPPED:- and -:SKIPPED_SUM:- entries.
FILE NAMING CONVENTIONS
The filename is in the format:
${timestamp}.dscdata.${format}
For example:
1154649660.dscdata.xml
DATA FORMATS
XML A dataset XML file has the following structure:
<array name="dataset-name" dimensions="2" start_time="unix-seconds"
stop_time="unix-seconds">
<dimension number="1" type="Label1"/>
<dimension number="2" type="Label2"/>
<data>
<Label1 val="D1-V1">
<Label2 val="D2-V1" count="N1"/>
<Label2 val="D2-V2" count="N2"/>
<Label2 val="D2-V3" count="N3"/>
</Label1>
<Label1 val="D1-V2">
<Label2 val="D2-V1" count="N1"/>
<Label2 val="D2-V2" count="N2"/>
<Label2 val="D2-V3" count="N3"/>
</Label1>
</data>
</array>
JSON A dataset JSON file has the following structure:
{
"name": "dataset-name",
"start_time": unix-seconds,
"stop_time": unix-seconds,
"dimensions": [ "Label1", "Label2" ],
"data": [
{
"Label1": "D1-V1",
"Label2": [
{ "val": "D2-V1", "count": N1 },
{ "val": "D2-V2", "count": N2 },
{ "val": "D2-V3", "count": N3 }
]
},
{
"Label1": "D1-V2-base64",
"base64": true,
"Label2": [
{ "val": "D2-V1", "count": N1 },
{ "val": "D2-V2-base64", "base64": true, "count": N2 },
{ "val": "D2-V3", "count": N3 }
]
}
]
}
dataset-name, Label1, and Label2 come from the dataset definition.
The start_time and stop_time attributes are given in Unix seconds. They are normally 60-seconds apart.
dsc usually starts a new measurement interval on 60 second boundaries. That is:
stop_time mod{60} == 0
The Label1 attributes (D1-V1, D1-V2) are values for the first dimension indexer. Similarly, the Label2
attributes (D2-V1, D2-V2 D2-V3) are values for the second dimension indexer. For some indexers these
values are numeric, for others they are strings. If the value contains certain non-printable characters,
the string is base64-encoded and the optional BASE64 attribute is set to 1/true.
There are two special vals that help keep large datasets down to a reasonable size: -:SKIPPED:- and
-:SKIPPED_SUM:-. These may be present on datasets that use the min-count and max-cells parameters (see
section PARAMETERS). -:SKIPPED:- is the number of cells that were not included in the output.
-:SKIPPED_SUM:-, is the sum of the counts for all the skipped cells.
Note that “one-dimensional datasets” still use two dimensions in the output. The first dimension type
and value will be “All” as shown in the example below:
<array name="rcode" dimensions="2" start_time="1154649600"
stop_time="1154649660">
<dimension number="1" type="All"/>
<dimension number="2" type="Rcode"/>
<data>
<All val="ALL">
<Rcode val="0" count="70945"/>
<Rcode val="3" count="50586"/>
<Rcode val="4" count="121"/>
<Rcode val="1" count="56"/>
<Rcode val="5" count="44"/>
</All>
</data>
</array>
The count values are always integers. If the count for a particular tuple is zero, it should not be
included in the output.
Note that the contents of the output do not indicate where it came from. In particular, the server and
node that it came from are not present.
GEOIP
Country code and AS number lookup is available using MaxMind GeoIP Legacy API if it was enabled during
compilation.
Multiple options can be give to the database and are directly linked to the options for GeoIP_open() but
without the prefix of GEOIP_, example:
geoip_v4_dat "/usr/local/share/GeoIP/GeoIP.dat" STANDARD MEMORY_CACHE;
geoip_asn_v6_dat "/usr/local/share/GeoIP/GeoIPASNumv6.dat" MEMORY_CACHE;
GeoIP documentation says:
STANDARD
Read database from file system. This uses the least memory.
MEMORY_CACHE
Load database into memory. Provides faster performance but uses more memory.
CHECK_CACHE
Check for updated database. If database has been updated, reload file handle and/or memory cache.
INDEX_CACHE
Cache only the the most frequently accessed index portion of the database, resulting in faster
lookups than GEOIP_STANDARD, but less memory usage than GEOIP_MEMORY_CACHE. This is useful for
larger databases such as GeoIP Legacy Organization and GeoIP Legacy City. Note: for GeoIP Legacy
Country, Region and Netspeed databases, GEOIP_INDEX_CACHE is equivalent to GEOIP_MEMORY_CACHE.
MMAP_CACHE
Load database into mmap shared memory. MMAP is not available for 32bit Windows.
EXAMPLE
local_address 127.0.0.1;
local_address ::1;
#local_address 127.0.0.0 255.0.0.0;
#local_address 192.168.0.0 24;
#local_address 10.0.0.0 8;
run_dir "/var/lib/dsc";
minfree_bytes 5000000;
pid_file "/run/dsc.pid";
# Example filters
#
#bpf_program "udp port 53";
#bpf_program "tcp port 53 or udp port 53";
# Use this to see only DNS *queries*
#
#bpf_program "udp dst port 53 and udp[10:2] & 0x8000 = 0";
#dns_port 53;
#pcap_buffer_size 4194304;
#pcap_thread_timeout 100;
#drop_ip_fragments;
interface eth0;
#interface any;
#dnstap_file /path/to/file.dnstap;
#dnstap_unixsock /path/to/unix.sock;
#dnstap_tcp 127.0.0.1 5353;
#dnstap_udp 127.0.0.1 5353;
#dnstap_network 127.0.0.1 ::1 53;
dataset qtype dns All:null Qtype:qtype queries-only;
dataset rcode dns All:null Rcode:rcode replies-only;
dataset opcode dns All:null Opcode:opcode queries-only;
dataset rcode_vs_replylen dns Rcode:rcode ReplyLen:msglen replies-only;
dataset client_subnet dns All:null ClientSubnet:client_subnet queries-only max-cells=200;
dataset qtype_vs_qnamelen dns Qtype:qtype QnameLen:qnamelen queries-only;
dataset qtype_vs_tld dns Qtype:qtype TLD:tld queries-only,popular-qtypes max-cells=200;
dataset certain_qnames_vs_qtype dns CertainQnames:certain_qnames Qtype:qtype queries-only;
dataset client_subnet2 dns Class:query_classification ClientSubnet:client_subnet queries-only max-cells=200;
dataset client_addr_vs_rcode dns Rcode:rcode ClientAddr:client replies-only max-cells=50;
dataset chaos_types_and_names dns Qtype:qtype Qname:qname chaos-class,queries-only;
#dataset country_code dns All:null CountryCode:country queries-only;
#dataset asn_all dns IPVersion:dns_ip_version ASN:asn queries-only max-cells=200;
dataset idn_qname dns All:null IDNQname:idn_qname queries-only;
dataset edns_version dns All:null EDNSVersion:edns_version queries-only;
dataset edns_bufsiz dns All:null EDNSBufSiz:edns_bufsiz queries-only;
dataset do_bit dns All:null D0:do_bit queries-only;
dataset rd_bit dns All:null RD:rd_bit queries-only;
dataset idn_vs_tld dns All:null TLD:tld queries-only,idn-only;
dataset ipv6_rsn_abusers dns All:null ClientAddr:client queries-only,aaaa-or-a6-only,root-servers-net-only max-cells=50;
dataset transport_vs_qtype dns Transport:transport Qtype:qtype queries-only;
dataset client_port_range dns All:null PortRange:dns_sport_range queries-only;
#dataset second_ld_vs_rcode dns Rcode:rcode SecondLD:second_ld replies-only max-cells=50;
#dataset third_ld_vs_rcode dns Rcode:rcode ThirdLD:third_ld replies-only max-cells=50;
dataset direction_vs_ipproto ip Direction:ip_direction IPProto:ip_proto any;
#dataset dns_ip_version_vs_qtype dns IPVersion:dns_ip_version Qtype:qtype queries-only;
#dataset response_time dns All:null ResponseTime:response_time;
#dataset priming_queries dns Transport:transport EDNSBufSiz:edns_bufsiz priming-query,queries-only;
#dataset priming_responses dns All:null ReplyLen:msglen priming-query,replies-only;
#dataset qr_aa_bits dns Direction:ip_direction QRAABits:qr_aa_bits any;
#dataset servfail_qname dns ALL:null Qname:qname servfail-only,replies-only;
#dataset ad_qname dns ALL:null Qname:qname authentic-data-only,replies-only;
#dataset label_count dns All:null LabelCount:label_count any;
#dataset encryption dns All:null Encryption:encryption queries-only;
#statistics_interval 60;
#no_wait_interval;
output_format XML;
#output_format JSON;
#output_user root;
#output_group root;
#output_mod 0664;
#geoip_v4_dat "/usr/share/GeoIP/GeoIP.dat" STANDARD MEMORY_CACHE MMAP_CACHE;
#geoip_v6_dat "/usr/share/GeoIP/GeoIPv6.dat";
#geoip_asn_v4_dat "/usr/share/GeoIP/GeoIPASNum.dat" MEMORY_CACHE;
#geoip_asn_v6_dat "/usr/share/GeoIP/GeoIPASNumv6.dat" MEMORY_CACHE;
#asn_indexer_backend geoip;
#country_indexer_backend geoip;
#maxminddb_asn "/path/to/GeoLite2/ASN.mmdb";
#maxminddb_country "/path/to/GeoLite2/Country.mmdb";
#client_v4_mask 255.255.255.0;
#client_v6_mask ffff:ffff:ffff:ffff:ffff:ffff:0000:0000;
#response_time_mode log10;
#response_time_max_queries 1000000;
#response_time_full_mode drop_query;
#response_time_max_seconds 5;
#response_time_max_sec_mode ceil;
#response_time_bucket_size 100;
#knowntlds_file file;
FILES
/etc/dsc/dsc.conf
/etc/dsc/dsc.conf.sample
SEE ALSO
dsc(1), dsc-psl-convert(1)
AUTHORS
Jerry Lundström, DNS-OARC
Duane Wessels, Measurement Factory / Verisign
Ken Keys, Cooperative Association for Internet Data Analysis
Sebastian Castro, New Zealand Registry Services
Maintained by DNS-OARC
https://www.dns-oarc.net/tools/dsc
BUGS
For issues and feature requests please use:
https://github.com/DNS-OARC/dsc/issues
For question and help please use:
dsc@dns-oarc.net
DNS Statistics Collector 2.15.2 dsc.conf(5)