draft-ietf-dnsop-as112-ops-09.txt   rfc6304.txt 
Network Working Group J. Abley Internet Engineering Task Force (IETF) J. Abley
Internet-Draft ICANN Request for Comments: 6304 ICANN
Intended status: Informational W. Maton Category: Informational W. Maton
Expires: November 12, 2011 NRC-CNRC ISSN: 2070-1721 NRC-CNRC
May 11, 2011 July 2011
AS112 Nameserver Operations AS112 Nameserver Operations
draft-ietf-dnsop-as112-ops-09
Abstract Abstract
Many sites connected to the Internet make use of IPv4 addresses that Many sites connected to the Internet make use of IPv4 addresses that
are not globally-unique. Examples are the addresses designated in are not globally unique. Examples are the addresses designated in
RFC 1918 for private use within individual sites. RFC 1918 for private use within individual sites.
Devices in such environments may occasionally originate Domain Name Devices in such environments may occasionally originate Domain Name
System (DNS) queries (so-called "reverse lookups") corresponding to System (DNS) queries (so-called "reverse lookups") corresponding to
those private-use addresses. Since the addresses concerned have only those private-use addresses. Since the addresses concerned have only
local significance, it is good practice for site administrators to local significance, it is good practice for site administrators to
ensure that such queries are answered locally. However, it is not ensure that such queries are answered locally. However, it is not
uncommon for such queries to follow the normal delegation path in the uncommon for such queries to follow the normal delegation path in the
public DNS instead of being answered within the site. public DNS instead of being answered within the site.
It is not possible for public DNS servers to give useful answers to It is not possible for public DNS servers to give useful answers to
such queries. In addition, due to the wide deployment of private-use such queries. In addition, due to the wide deployment of private-use
addresses and the continuing growth of the Internet, the volume of addresses and the continuing growth of the Internet, the volume of
such queries is large and growing. The AS112 project aims to provide such queries is large and growing. The AS112 project aims to provide
a distributed sink for such queries in order to reduce the load on a distributed sink for such queries in order to reduce the load on
the IN-ADDR.ARPA authoritative servers. The AS112 project is named the IN-ADDR.ARPA authoritative servers. The AS112 project is named
after the Autonomous System Number (ASN) that was assigned to it. after the Autonomous System Number (ASN) that was assigned to it.
This document describes the steps required to install a new AS112 This document describes the steps required to install a new AS112
node, and offers advice relating to such a node's operation. node and offers advice relating to such a node's operation.
Status of this Memo
This Internet-Draft is submitted in full conformance with the Status of This Memo
provisions of BCP 78 and BCP 79.
Internet-Drafts are working documents of the Internet Engineering This document is not an Internet Standards Track specification; it is
Task Force (IETF). Note that other groups may also distribute published for informational purposes.
working documents as Internet-Drafts. The list of current Internet-
Drafts is at http://datatracker.ietf.org/drafts/current/.
Internet-Drafts are draft documents valid for a maximum of six months This document is a product of the Internet Engineering Task Force
and may be updated, replaced, or obsoleted by other documents at any (IETF). It represents the consensus of the IETF community. It has
time. It is inappropriate to use Internet-Drafts as reference received public review and has been approved for publication by the
material or to cite them other than as "work in progress." Internet Engineering Steering Group (IESG). Not all documents
approved by the IESG are a candidate for any level of Internet
Standard; see Section 2 of RFC 5741.
This Internet-Draft will expire on November 12, 2011. Information about the current status of this document, any errata,
and how to provide feedback on it may be obtained at
http://www.rfc-editor.org/info/rfc6304.
Copyright Notice Copyright Notice
Copyright (c) 2011 IETF Trust and the persons identified as the Copyright (c) 2011 IETF Trust and the persons identified as the
document authors. All rights reserved. document authors. All rights reserved.
This document is subject to BCP 78 and the IETF Trust's Legal This document is subject to BCP 78 and the IETF Trust's Legal
Provisions Relating to IETF Documents Provisions Relating to IETF Documents
(http://trustee.ietf.org/license-info) in effect on the date of (http://trustee.ietf.org/license-info) in effect on the date of
publication of this document. Please review these documents publication of this document. Please review these documents
skipping to change at page 3, line 7 skipping to change at page 3, line 7
modifications of such material outside the IETF Standards Process. modifications of such material outside the IETF Standards Process.
Without obtaining an adequate license from the person(s) controlling Without obtaining an adequate license from the person(s) controlling
the copyright in such materials, this document may not be modified the copyright in such materials, this document may not be modified
outside the IETF Standards Process, and derivative works of it may outside the IETF Standards Process, and derivative works of it may
not be created outside the IETF Standards Process, except to format not be created outside the IETF Standards Process, except to format
it for publication as an RFC or to translate it into languages other it for publication as an RFC or to translate it into languages other
than English. than English.
Table of Contents Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 4 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 3
2. AS112 DNS Service . . . . . . . . . . . . . . . . . . . . . . 5 2. AS112 DNS Service . . . . . . . . . . . . . . . . . . . . . . 4
2.1. Zones . . . . . . . . . . . . . . . . . . . . . . . . . . 5 2.1. Zones . . . . . . . . . . . . . . . . . . . . . . . . . . 4
2.2. Nameservers . . . . . . . . . . . . . . . . . . . . . . . 5 2.2. Nameservers . . . . . . . . . . . . . . . . . . . . . . . 4
3. Installation of a New Node . . . . . . . . . . . . . . . . . . 6 3. Installation of a New Node . . . . . . . . . . . . . . . . . . 5
3.1. Useful Background Knowledge . . . . . . . . . . . . . . . 6 3.1. Useful Background Knowledge . . . . . . . . . . . . . . . 5
3.2. Topological Location . . . . . . . . . . . . . . . . . . . 6 3.2. Topological Location . . . . . . . . . . . . . . . . . . . 5
3.3. Operating System and Host Considerations . . . . . . . . . 6 3.3. Operating System and Host Considerations . . . . . . . . . 5
3.4. Routing Software . . . . . . . . . . . . . . . . . . . . . 7 3.4. Routing Software . . . . . . . . . . . . . . . . . . . . . 6
3.5. DNS Software . . . . . . . . . . . . . . . . . . . . . . . 8 3.5. DNS Software . . . . . . . . . . . . . . . . . . . . . . . 8
3.6. Testing a Newly-Installed Node . . . . . . . . . . . . . . 12 3.6. Testing a Newly Installed Node . . . . . . . . . . . . . . 11
4. Operations . . . . . . . . . . . . . . . . . . . . . . . . . . 13 4. Operations . . . . . . . . . . . . . . . . . . . . . . . . . . 12
4.1. Monitoring . . . . . . . . . . . . . . . . . . . . . . . . 13 4.1. Monitoring . . . . . . . . . . . . . . . . . . . . . . . . 12
4.2. Downtime . . . . . . . . . . . . . . . . . . . . . . . . . 13 4.2. Downtime . . . . . . . . . . . . . . . . . . . . . . . . . 12
4.3. Statistics and Measurement . . . . . . . . . . . . . . . . 13 4.3. Statistics and Measurement . . . . . . . . . . . . . . . . 12
5. Communications . . . . . . . . . . . . . . . . . . . . . . . . 14 5. Communications . . . . . . . . . . . . . . . . . . . . . . . . 12
6. On the Future of AS112 Nodes . . . . . . . . . . . . . . . . . 15 6. On the Future of AS112 Nodes . . . . . . . . . . . . . . . . . 13
7. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 16 7. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 13
8. Security Considerations . . . . . . . . . . . . . . . . . . . 17 8. Security Considerations . . . . . . . . . . . . . . . . . . . 14
9. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . 18 9. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . 14
10. References . . . . . . . . . . . . . . . . . . . . . . . . . . 19 10. References . . . . . . . . . . . . . . . . . . . . . . . . . . 15
10.1. Normative References . . . . . . . . . . . . . . . . . . . 19 10.1. Normative References . . . . . . . . . . . . . . . . . . . 15
10.2. Informative References . . . . . . . . . . . . . . . . . . 19 10.2. Informative References . . . . . . . . . . . . . . . . . . 15
Appendix A. History . . . . . . . . . . . . . . . . . . . . . . . 21 Appendix A. History . . . . . . . . . . . . . . . . . . . . . . . 17
Appendix B. Change History . . . . . . . . . . . . . . . . . . . 22
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 23
1. Introduction 1. Introduction
Many sites connected to the Internet make use of IPv4 addresses that Many sites connected to the Internet make use of IPv4 addresses that
are not globally unique. Examples are the addresses designated in are not globally unique. Examples are the addresses designated in
[RFC1918] for private use within individual sites. [RFC1918] for private use within individual sites.
Devices in such environments may occasionally originate Domain Name Devices in such environments may occasionally originate Domain Name
System (DNS) [RFC1034] queries (so-called "reverse lookups") System (DNS) [RFC1034] queries (so-called "reverse lookups")
corresponding to those private-use addresses. Since the addresses corresponding to those private-use addresses. Since the addresses
concerned have only local significance, it is good practice for site concerned have only local significance, it is good practice for site
administrators to ensure that such queries are answered locally administrators to ensure that such queries are answered locally
[I-D.ietf-dnsop-default-local-zones]. However, it is not uncommon [RFC6303]. However, it is not uncommon for such queries to follow
for such queries to follow the normal delegation path in the public the normal delegation path in the public DNS instead of being
DNS instead of being answered within the site. answered within the site.
It is not possible for public DNS servers to give useful answers to It is not possible for public DNS servers to give useful answers to
such queries. In addition, due to the wide deployment of private-use such queries. In addition, due to the wide deployment of private-use
addresses and the continuing growth of the Internet, the volume of addresses and the continuing growth of the Internet, the volume of
such queries is large and growing. The AS112 project aims to provide such queries is large and growing. The AS112 project aims to provide
a distributed sink for such queries in order to reduce the load on a distributed sink for such queries in order to reduce the load on
the IN-ADDR.ARPA authoritative servers [RFC5855]. the IN-ADDR.ARPA authoritative servers [RFC5855].
The AS112 project encompasses a loosely coordinated collection of The AS112 project encompasses a loosely coordinated collection of
independently operated nameservers. Each nameserver functions as a independently operated nameservers. Each nameserver functions as a
single node in an AS112 anycast cloud [RFC4786], and is configured to single node in an AS112 anycast cloud [RFC4786] and is configured to
answer authoritatively for a particular set of nominated zones. answer authoritatively for a particular set of nominated zones.
The AS112 project is named after the Autonomous System Number (ASN) The AS112 project is named after the Autonomous System Number (ASN)
that was assigned to it. that was assigned to it.
2. AS112 DNS Service 2. AS112 DNS Service
2.1. Zones 2.1. Zones
AS112 nameservers answer authoritatively for the following zones, AS112 nameservers answer authoritatively for the following zones,
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3. Installation of a New Node 3. Installation of a New Node
3.1. Useful Background Knowledge 3.1. Useful Background Knowledge
Installation of an AS112 node is relatively straightforward. Installation of an AS112 node is relatively straightforward.
However, experience in the following general areas may prove useful: However, experience in the following general areas may prove useful:
o inter-domain routing with BGP [RFC4271]; o inter-domain routing with BGP [RFC4271];
o DNS authoritative server operations; o DNS authoritative server operations; and
o anycast [RFC4786] distribution of DNS services. o anycast [RFC4786] distribution of DNS services.
3.2. Topological Location 3.2. Topological Location
AS112 nodes may be located anywhere on the Internet. For nodes that AS112 nodes may be located anywhere on the Internet. For nodes that
are intended to provide a public service to the Internet community are intended to provide a public service to the Internet community
(as opposed to private use), it may well be advantageous to choose a (as opposed to private use), it may well be advantageous to choose a
location that is easily (and cheaply) reachable by multiple location that is easily (and cheaply) reachable by multiple
providers, such as an Internet exchange point. providers, such as an Internet Exchange Point.
AS112 nodes may advertise their service prefix to BGP peers for local AS112 nodes may advertise their service prefix to BGP peers for local
use (analogous to a conventional peering relationship between two use (analogous to a conventional peering relationship between two
providers) or for global use (analogous to a customer relationship providers) or for global use (analogous to a customer relationship
with one or more providers). with one or more providers).
It is good operational practice to notify the community of users that It is good operational practice to notify the community of users that
may fall within the reach of a new AS112 node before it is installed. may fall within the reach of a new AS112 node before it is installed.
At an Internet Exchange, local mailing lists usually exist to At an Internet Exchange, local mailing lists usually exist to
facilitate such announcements. For nodes that are intended to be facilitate such announcements. For nodes that are intended to be
globally reachable, coordination with other AS112 operators is highly globally reachable, coordination with other AS112 operators is highly
recommended. See also Section 5. recommended. See also Section 5.
3.3. Operating System and Host Considerations 3.3. Operating System and Host Considerations
Examples in this document are based on UNIX and UNIX-like operating Examples in this document are based on UNIX and UNIX-like operating
systems, but other operating systems exist which are suitable for use systems, but other operating systems exist that are suitable for use
in construction of an AS112 node. in construction of an AS112 node.
The chosen platform should include support for either cloned loopback The chosen platform should include either support for cloned loopback
interfaces, or the capability to bind multiple addresses to a single interfaces or the capability to bind multiple addresses to a single
loopback interface. The addresses of the nameservers listed in loopback interface. The addresses of the nameservers listed in
Section 2.2 will be configured on these interfaces in order that the Section 2.2 will be configured on these interfaces in order that the
DNS software can respond to queries properly. DNS software can respond to queries properly.
A host that is configured to act as an AS112 anycast node should be A host that is configured to act as an AS112 anycast node should be
dedicated to that purpose, and should not be used to simultaneously dedicated to that purpose and should not be used to simultaneously
provide other services. This guidance is provided due to the provide other services. This guidance is provided due to the
unpredictable (and occasionally high) traffic levels that AS112 nodes unpredictable (and occasionally high) traffic levels that AS112 nodes
have been seen to attract. have been seen to attract.
System startup scripts should be arranged such that the various System startup scripts should be arranged such that the various
AS112-related components start automatically following a system AS112-related components start automatically following a system
reboot. The order in which interfaces are configured and software reboot. The order in which interfaces are configured and software
components started should be arranged such that routing software components started should be arranged such that routing software
startup follows DNS software startup, and DNS software startup startup follows DNS software startup, and DNS software startup
follows loopback interface configuration. follows loopback interface configuration.
Wrapper scripts or other arrangements should be employed to ensure Wrapper scripts or other arrangements should be employed to ensure
that the anycast service prefix for AS112 is not advertised while that the anycast service prefix for AS112 is not advertised while
either the anycast addresses are not configured, or while the DNS either the anycast addresses are not configured or the DNS software
software is not running. is not running.
3.4. Routing Software 3.4. Routing Software
AS112 nodes signal the availability of AS112 nameservers to the AS112 nodes signal the availability of AS112 nameservers to the
Internet using BGP [RFC4271]: each AS112 node is a BGP speaker, and Internet using BGP [RFC4271]: each AS112 node is a BGP speaker and
announces the prefix 192.175.48.0/24 to the Internet with origin AS announces the prefix 192.175.48.0/24 to the Internet with origin AS
112 (see also Section 2.2). 112 (see also Section 2.2).
The examples in this document are based on the Quagga Routing The examples in this document are based on the Quagga Routing Suite
Suite [1] running on Linux, but other software packages exist which [QUAGGA] running on Linux, but other software packages exist that
also provide suitable BGP support for AS112 nodes. also provide suitable BGP support for AS112 nodes.
The "bgpd.conf" file is used by Quagga's bgpd daemon, which provides The "bgpd.conf" file is used by Quagga's bgpd daemon, which provides
BGP protocol support. The router id in this example is 203.0.113.1; BGP support. The router ID in this example is 203.0.113.1; the AS112
the AS112 node peers with external peers 192.0.2.1 and 192.0.2.2. node peers with external peers 192.0.2.1 and 192.0.2.2. Note the
Note the local AS number 112, and the origination of the prefix local AS number is 112, and the service prefix originated from the
192.175.48.0/24. AS112 node is 192.175.48.0/24.
! bgpd.conf ! bgpd.conf
! !
hostname as112-bgpd hostname as112-bgpd
password <something> password <something>
enable password <supersomething> enable password <supersomething>
! !
! Note that all AS112 nodes use the local Autonomous System ! Note that all AS112 nodes use the local Autonomous System
! Number 112, and originate the IPv4 prefix 192.175.48.0/24. ! Number 112, and originate the IPv4 prefix 192.175.48.0/24.
! All other addresses shown below are illustrative, and ! All other addresses shown below are illustrative, and
! actual numbers will depend on local circumstances. ! actual numbers will depend on local circumstances.
! !
router bgp 112 router bgp 112
bgp router-id 203.0.113.1 bgp router-id 203.0.113.1
network 192.175.48.0 network 192.175.48.0
neighbor 192.0.2.1 remote-as 64496 neighbor 192.0.2.1 remote-as 64496
neighbor 192.0.2.1 next-hop-self neighbor 192.0.2.1 next-hop-self
neighbor 192.0.2.1 prefix-list AS112 out
neighbor 192.0.2.1 filter-list 1 out
neighbor 192.0.2.2 remote-as 64497 neighbor 192.0.2.2 remote-as 64497
neighbor 192.0.2.2 next-hop-self neighbor 192.0.2.2 next-hop-self
neighbor 192.0.2.2 prefix-list AS112 out
neighbor 192.0.2.2 filter-list 1 out
!
ip prefix-list AS112 permit 192.175.48.0/24
!
ip as-path access-list 1 permit ^$
The configuration above includes a double-blinded restriction on what
the AS112 node shall advertise to the pair of BGP neighbors.
Firstly, that prefix-list "AS112" only containing the service prefix
192.175.48.0/24 shall be advertised. Secondly, the "ip as-path
access-list 1" statement contains a one-line regular expression that
permits only the local AS number (112 in this case) and no other to
be advertised as well. Both statements prevent the node from
becoming a transit router. Equivalent restrictions using other BGP
implementations should be utilised.
The "zebra.conf" file is required to provide integration between The "zebra.conf" file is required to provide integration between
protocol daemons (bgpd, in this case) and the kernel. protocol daemons (bgpd, in this case) and the kernel.
! zebra.conf ! zebra.conf
! !
hostname as112 hostname as112
password <something> password <something>
enable password <supersomething> enable password <supersomething>
! !
interface lo interface lo
! !
interface eth0 interface eth0
! !
3.5. DNS Software 3.5. DNS Software
Although the queries received by AS112 nodes are definitively Although the queries received by AS112 nodes are definitively
misdirected, it is important that they be answered in a manner that misdirected, it is important that they be answered in a manner that
is accurate and consistent. For this reason AS112 nodes operate as is accurate and consistent. For this reason, AS112 nodes operate as
fully-functional and standards-compliant DNS authoritative servers fully functional and standards-compliant DNS authoritative servers
[RFC1034], and hence require DNS software. [RFC1034], and hence require DNS software.
Examples in this document are based on ISC BIND9 [2], but other DNS Examples in this document are based on ISC BIND9 [BIND], but other
software exists which is suitable for use in construction of an AS112 DNS software exists that is suitable for use in construction of an
node. AS112 node.
The following is a sample BIND9 "named.conf" file for a dedicated The following is a sample BIND9 "named.conf" file for a dedicated
AS112 server. Note that the nameserver is configured to act as an AS112 server. Note that the nameserver is configured to act as an
authoritative-only server (i.e. recursion is disabled). The authoritative-only server (i.e., recursion is disabled). The
nameserver is also configured to listen on the various AS112 anycast nameserver is also configured to listen on the various AS112 anycast
nameserver addresses, as well as its local addresses. nameserver addresses, as well as its local addresses.
// named.conf // named.conf
// global options // global options
options { options {
listen-on { listen-on {
127.0.0.1; // localhost 127.0.0.1; // localhost
// the following address is node-dependent, and should be set to // The following address is node-dependent and should be set to
// something appropriate for the new AS112 node // something appropriate for the new AS112 node.
203.0.113.1; // local address (globally-unique, unicast) 203.0.113.1; // local address (globally unique, unicast)
// the following addresses correspond to AS112 addresses, and // the following addresses correspond to AS112 addresses, and
// are the same for all AS112 nodes // are the same for all AS112 nodes
192.175.48.1; // prisoner.iana.org (anycast) 192.175.48.1; // prisoner.iana.org (anycast)
192.175.48.6; // blackhole-1.iana.org (anycast) 192.175.48.6; // blackhole-1.iana.org (anycast)
192.175.48.42; // blackhole-2.iana.org (anycast) 192.175.48.42; // blackhole-2.iana.org (anycast)
}; };
directory "/var/named"; directory "/var/named";
recursion no; // authoritative-only server recursion no; // authoritative-only server
query-source address *; query-source address *;
}; };
// log queries, so that when people call us about unexpected // Log queries, so that when people call us about unexpected
// answers to queries they didn't realise they had sent, we // answers to queries they didn't realise they had sent, we
// have something to talk about. Note that activating this // have something to talk about. Note that activating this
// has the potential to create high CPU load and consume // has the potential to create high CPU load and consume
// enormous amounts of disk space. // enormous amounts of disk space.
logging { logging {
channel "querylog" { channel "querylog" {
file "/var/log/query.log" versions 2 size 500m; file "/var/log/query.log" versions 2 size 500m;
print-time yes; print-time yes;
}; };
skipping to change at page 10, line 23 skipping to change at page 9, line 50
zone "28.172.in-addr.arpa" { type master; file "db.empty"; }; zone "28.172.in-addr.arpa" { type master; file "db.empty"; };
zone "29.172.in-addr.arpa" { type master; file "db.empty"; }; zone "29.172.in-addr.arpa" { type master; file "db.empty"; };
zone "30.172.in-addr.arpa" { type master; file "db.empty"; }; zone "30.172.in-addr.arpa" { type master; file "db.empty"; };
zone "31.172.in-addr.arpa" { type master; file "db.empty"; }; zone "31.172.in-addr.arpa" { type master; file "db.empty"; };
zone "168.192.in-addr.arpa" { type master; file "db.empty"; }; zone "168.192.in-addr.arpa" { type master; file "db.empty"; };
// RFC 5735 // RFC 5735
zone "254.169.in-addr.arpa" { type master; file "db.empty"; }; zone "254.169.in-addr.arpa" { type master; file "db.empty"; };
// also answer authoritatively for the HOSTNAME.AS112.NET zone, // Also answer authoritatively for the HOSTNAME.AS112.NET zone,
// which contains data of operational relevance // which contains data of operational relevance.
zone "hostname.as112.net" { zone "hostname.as112.net" {
type master; type master;
file "db.hostname.as112.net"; file "db.hostname.as112.net";
}; };
The "db.empty" file follows, below. This is the source data used to The "db.empty" file follows, below. This is the source data used to
populate all the IN-ADDR.ARPA zones listed in Section 2.1. Note that populate all the IN-ADDR.ARPA zones listed in Section 2.1. Note that
the RNAME specified in the SOA record corresponds to the RNAME specified in the SOA record corresponds to
hostmaster@root-servers.org, a suitable e-mail address for receiving hostmaster@root-servers.org, a suitable email address for receiving
technical queries about these zones. technical queries about these zones.
; db.empty ; db.empty
; ;
; Empty zone for AS112 server. ; Empty zone for AS112 server.
; ;
$TTL 1W $TTL 1W
@ IN SOA prisoner.iana.org. hostmaster.root-servers.org. ( @ IN SOA prisoner.iana.org. hostmaster.root-servers.org. (
1 ; serial number 1 ; serial number
1W ; refresh 1W ; refresh
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NS blackhole-2.iana.org. NS blackhole-2.iana.org.
; ;
; There should be no other resource records included in this zone. ; There should be no other resource records included in this zone.
; ;
; Records that relate to RFC 1918-numbered resources within the ; Records that relate to RFC 1918-numbered resources within the
; site hosting this AS112 node should not be hosted on this ; site hosting this AS112 node should not be hosted on this
; nameserver. ; nameserver.
The "db.hostname.as112.net" file follows, below. This zone contains The "db.hostname.as112.net" file follows, below. This zone contains
various resource records that provide operational data to users for various resource records that provide operational data to users for
troubleshooting or measurement purposes, and should be edited to suit troubleshooting or measurement purposes; the data should be edited to
local circumstances. Note that the response to the query suit local circumstances. Note that the response to the query
"HOSTNAME.AS112.NET IN TXT" should fit within a 512 octet DNS/UDP "HOSTNAME.AS112.NET IN TXT" should fit within a 512-octet DNS/UDP
datagram: i.e. it should be available over UDP transport without datagram: i.e., it should be available over UDP transport without
requiring EDNS0 support. requiring EDNS0 support.
The optional LOC record [RFC1876] included in the zone apex provides The optional LOC record [RFC1876] included in the zone apex provides
information about the geospatial location of the node. information about the geospatial location of the node.
; db.hostname.as112.net ; db.hostname.as112.net
; ;
$TTL 1W $TTL 1W
@ SOA server.example.net. admin.example.net. ( @ SOA server.example.net. admin.example.net. (
1 ; serial number 1 ; serial number
skipping to change at page 12, line 6 skipping to change at page 11, line 23
1W ) ; negative caching TTL 1W ) ; negative caching TTL
; ;
NS blackhole-2.iana.org. NS blackhole-2.iana.org.
NS blackhole-1.iana.org. NS blackhole-1.iana.org.
; ;
TXT "Name of Facility or similar" "City, Country" TXT "Name of Facility or similar" "City, Country"
TXT "See http://www.as112.net/ for more information." TXT "See http://www.as112.net/ for more information."
; ;
LOC 45 25 0.000 N 75 42 0.000 W 80.00m 1m 10000m 10m LOC 45 25 0.000 N 75 42 0.000 W 80.00m 1m 10000m 10m
3.6. Testing a Newly-Installed Node 3.6. Testing a Newly Installed Node
The BIND9 tool "dig" can be used to retrieve the TXT resource records The BIND9 tool "dig" can be used to retrieve the TXT resource records
associated with the domain "HOSTNAME.AS112.NET", directed at one of associated with the domain "HOSTNAME.AS112.NET", directed at one of
the AS112 anycast nameserver addresses. Continuing the example from the AS112 anycast nameserver addresses. Continuing the example from
above, the response received should indicate the identity of the above, the response received should indicate the identity of the
AS112 node that responded to the query. See Section 3.5 for more AS112 node that responded to the query. See Section 3.5 for more
details about the resource records associated with details about the resource records associated with
"HOSTNAME.AS112.NET". "HOSTNAME.AS112.NET".
% dig @prisoner.iana.org hostname.as112.net txt +short +norec % dig @prisoner.iana.org hostname.as112.net txt +short +norec
"Name of Facility or similar" "City, Country" "Name of Facility or similar" "City, Country"
"See http://www.as112.net/ for more information." "See http://www.as112.net/ for more information."
% %
If the response received indicates a different node is being used, If the response received indicates a different node is being used,
then there is probably a routing problem to solve. If there is no then there is probably a routing problem to solve. If there is no
response received at all, there might be host or nameserver problem. response received at all, there might be a host or nameserver
Judicious use of tools such as traceroute, and consultation of BGP problem. Judicious use of tools such as traceroute and consultation
looking glasses might be useful in troubleshooting. of BGP looking glasses might be useful in troubleshooting.
Note that an appropriate set of tests for a new server will include Note that an appropriate set of tests for a new server will include
queries sent from many different places within the expected service queries sent from many different places within the expected service
area of the node, using both UDP and TCP transport, and exercising area of the node, using both UDP and TCP transport, and exercising
all three AS112 anycast nameserver addresses. all three AS112 anycast nameserver addresses.
4. Operations 4. Operations
4.1. Monitoring 4.1. Monitoring
AS112 nodes should be monitored to ensure they are functioning AS112 nodes should be monitored to ensure they are functioning
correctly, just as with any other production service. An AS112 node correctly, just as with any other production service. An AS112 node
that stops answering queries correctly can cause failures and that stops answering queries correctly can cause failures and
timeouts in unexpected places and can lead to failures in dependent timeouts in unexpected places and can lead to failures in dependent
systems that can be difficult to troubleshoot. systems that can be difficult to troubleshoot.
4.2. Downtime 4.2. Downtime
An AS112 node that needs to go off-line (e.g. for planned maintenance An AS112 node that needs to go off-line (e.g., for planned
or as part of the diagnosis of some problem) should stop advertising maintenance or as part of the diagnosis of some problem) should stop
the AS112 service prefix to its BGP peers. This can be done by advertising the AS112 service prefix to its BGP peers. This can be
shutting down the routing software on the node altogether or by done by shutting down the routing software on the node altogether or
causing the routing system to withdraw the route. by causing the routing system to withdraw the route.
Withdrawing the service prefix is important in order to avoid Withdrawing the service prefix is important in order to avoid
blackholing query traffic in the event that the DNS software on the blackholing query traffic in the event that the DNS software on the
node is not functioning normally. node is not functioning normally.
4.3. Statistics and Measurement 4.3. Statistics and Measurement
Use of the AS112 node should be measured in order to track long-term Use of the AS112 node should be measured in order to track long-term
trends, identify anomalous conditions, and to ensure that the trends, identify anomalous conditions, and ensure that the
configuration of the AS112 node is sufficient to handle the query configuration of the AS112 node is sufficient to handle the query
load. load.
Examples of free monitoring tools that might be useful to operators Examples of free monitoring tools that might be useful to operators
of AS112 nodes include: of AS112 nodes include:
o bindgraph [3] o bindgraph [BINDGRAPH]
o dnstop [4] o dnstop [DNSTOP]
o DSC [5] o DSC [DSC]
5. Communications 5. Communications
It is good operational practice to notify the community of users that It is good operational practice to notify the community of users that
may fall within the reach of a new AS112 node before it is installed. may fall within the reach of a new AS112 node before it is installed.
At Internet Exchanges, local mailing lists usually exist to At Internet Exchanges, local mailing lists usually exist to
facilitate such announcements. facilitate such announcements.
For nodes that are intended to be globally reachable, coordination For nodes that are intended to be globally reachable, coordination
with other AS112 operators is especially recommended. The mailing with other AS112 operators is especially recommended. The mailing
list <mailto:as112-ops@lists.dns-oarc.net> is operated for this list <as112-ops@lists.dns-oarc.net> is operated for this purpose.
purpose.
Information pertinent to AS112 operations is maintained at Information pertinent to AS112 operations is maintained at
<http://www.as112.net/>. <http://www.as112.net/>.
Information about an AS112 node should also be published within the Information about an AS112 node should also be published within the
DNS, within the "HOSTNAME.AS112.NET" zone. See Section 3.5 for more DNS, within the "HOSTNAME.AS112.NET" zone. See Section 3.5 for more
details. details.
6. On the Future of AS112 Nodes 6. On the Future of AS112 Nodes
It is recommended practice for the operators of recursive nameservers It is recommended practice for the operators of recursive nameservers
to answer queries for zones served by AS112 nodes locally, such that to answer queries for zones served by AS112 nodes locally, such that
queries never have an opportunity to reach AS112 servers queries never have an opportunity to reach AS112 servers [RFC6303].
[I-D.ietf-dnsop-default-local-zones]. Operational experience with Operational experience with AS112 nodes does not currently indicate
AS112 nodes does not currently indicate an observable trend towards an observable trend towards compliance with those recommendations,
compliance with those recommendations, however. however.
It is expected that some DNS software vendors will include default It is expected that some DNS software vendors will include default
configuration that will implement measures such as those described in configuration that will implement measures such as those described in
[I-D.ietf-dnsop-default-local-zones]. If such software is widely [RFC6303]. If such software is widely deployed, it is reasonable to
deployed, it is reasonable to assume that the query load received by assume that the query load received by AS112 nodes will decrease;
AS112 nodes will decrease; however, it is safe to assume that the however, it is safe to assume that the query load will not decrease
query load will not decrease to zero, and consequently that AS112 to zero, and consequently that AS112 nodes will continue to provide a
nodes will continue to provide a useful service for the foreseeable useful service for the foreseeable future.
future.
There may be a requirement in the future for AS112 nodes to answer There may be a requirement in the future for AS112 nodes to answer
for their current set of zones over IPv6 transport. Such a for their current set of zones over IPv6 transport. Such a
requirement would necessitate the assignment of a corresponding IPv6 requirement would necessitate the assignment of a corresponding IPv6
netblock for use as an anycast service prefix. netblock for use as an anycast service prefix.
There may be a requirement in the future for AS112 nodes to serve There may be a requirement in the future for AS112 nodes to serve
additional zones, or to stop serving particular zones that are additional zones or to stop serving particular zones that are
currently served. Such changes would be widely announced in currently served. Such changes would be widely announced in
operational forums, and published at <http://www.as112.net/>. operational forums and published at <http://www.as112.net/>.
7. IANA Considerations 7. IANA Considerations
The AS112 nameservers are all named under the domain IANA.ORG (see The AS112 nameservers are all named under the domain IANA.ORG (see
Section 2.2). However, the anycast infrastructure itself is operated Section 2.2). However, the anycast infrastructure itself is operated
by a loosely-coordinated, diverse mix of organisations across the by a loosely coordinated, diverse mix of organisations across the
Internet, and is not an IANA function. Internet, and is not an IANA function.
The autonomous system number 112 and the IPv4 prefix 192.175.48.0/24 The Autonomous System Number 112 and the IPv4 prefix 192.175.48.0/24
were assigned by ARIN. were assigned by ARIN.
This document makes no request of the IANA.
8. Security Considerations 8. Security Considerations
Hosts should never normally send queries to AS112 servers; queries Hosts should never normally send queries to AS112 servers; queries
relating to private-use addresses should be answered locally within a relating to private-use addresses should be answered locally within a
site. Hosts that send queries to AS112 servers may well leak site. Hosts that send queries to AS112 servers may well leak
information relating to private infrastructure to the public network, information relating to private infrastructure to the public network,
and this could present a security risk. This risk is orthogonal to and this could present a security risk. This risk is orthogonal to
the presence or absence of authoritative servers for these zones in the presence or absence of authoritative servers for these zones in
the public DNS infrastructure, however. the public DNS infrastructure, however.
Queries that are answered by AS112 servers are usually unintentional; Queries that are answered by AS112 servers are usually unintentional;
it follows that the responses from AS112 servers are usually it follows that the responses from AS112 servers are usually
unexpected. Unexpected inbound traffic can trigger intrusion unexpected. Unexpected inbound traffic can trigger intrusion
detection systems or alerts by firewalls. Operators of AS112 servers detection systems or alerts by firewalls. Operators of AS112 servers
should be prepared to be contacted by operators of remote should be prepared to be contacted by operators of remote
infrastructure who believe their security has been violated. Advice infrastructure who believe their security has been violated. Advice
to those who mistakenly believe that responses from AS112 nodes to those who mistakenly believe that responses from AS112 nodes
constitutes an attack on their infrastructure can be found in constitute an attack on their infrastructure can be found in
[I-D.ietf-dnsop-as112-under-attack-help-help]. [RFC6305].
The deployment of AS112 nodes is very loosely coordinated compared to The deployment of AS112 nodes is very loosely coordinated compared to
other services distributed using anycast. The malicious compromise other services distributed using anycast. The malicious compromise
of an AS112 node and subversion of the data served by the node is of an AS112 node and subversion of the data served by the node are
hence more difficult to detect due to the lack of central management. hence more difficult to detect due to the lack of central management.
Since it is conceivable that changing the responses to queries Since it is conceivable that changing the responses to queries
received by AS112 nodes might influence the behaviour of the hosts received by AS112 nodes might influence the behaviour of the hosts
sending the queries, such a compromise might be used as an attack sending the queries, such a compromise might be used as an attack
vector against private infrastructure. vector against private infrastructure.
Operators of AS112 should take appropriate measures to ensure that Operators of AS112 should take appropriate measures to ensure that
AS112 nodes are appropriately protected from compromise, such as AS112 nodes are appropriately protected from compromise, such as
would normally be employed for production nameserver or network would normally be employed for production nameserver or network
infrastructure. The guidance provided for root nameservers in infrastructure. The guidance provided for root nameservers in
[RFC2870] may be instructive. [RFC2870] may be instructive.
The zones hosted by AS112 servers are not signed with DNSSEC The zones hosted by AS112 servers are not signed with DNSSEC
[RFC4033]. Given the distributed and loosely-coordinated structure [RFC4033]. Given the distributed and loosely coordinated structure
of the AS112 service, the zones concerned could only be signed if the of the AS112 service, the zones concerned could only be signed if the
private key material used was effectively public, obviating any private key material used was effectively public, obviating any
security benefit resulting from the use of those keys. security benefit resulting from the use of those keys.
9. Acknowledgements 9. Acknowledgements
The authors wish to acknowledge the assistance of Bill Manning, John The authors wish to acknowledge the assistance of Bill Manning, John
Brown, Marco D'Itri, Daniele Arena, Stephane Bortzmeyer, Frank Brown, Marco D'Itri, Daniele Arena, Stephane Bortzmeyer, Frank
Habicht, Chris Thompson, Peter Losher, Peter Koch, Alfred Hoenes and Habicht, Chris Thompson, Peter Losher, Peter Koch, Alfred Hoenes, S.
S. Moonesamy in the preparation of this document. Moonesamy, and Mehmet Akcin in the preparation of this document.
10. References 10. References
10.1. Normative References 10.1. Normative References
[RFC1034] Mockapetris, P., "Domain names - concepts and facilities", [RFC1034] Mockapetris, P., "Domain names - concepts and
STD 13, RFC 1034, November 1987. facilities", STD 13, RFC 1034, November 1987.
[RFC1918] Rekhter, Y., Moskowitz, R., Karrenberg, D., Groot, G., and [RFC1918] Rekhter, Y., Moskowitz, R., Karrenberg, D., Groot, G.,
E. Lear, "Address Allocation for Private Internets", and E. Lear, "Address Allocation for Private Internets",
BCP 5, RFC 1918, February 1996. BCP 5, RFC 1918, February 1996.
[RFC2870] Bush, R., Karrenberg, D., Kosters, M., and R. Plzak, "Root [RFC2870] Bush, R., Karrenberg, D., Kosters, M., and R. Plzak,
Name Server Operational Requirements", BCP 40, RFC 2870, "Root Name Server Operational Requirements", BCP 40,
June 2000. RFC 2870, June 2000.
[RFC4033] Arends, R., Austein, R., Larson, M., Massey, D., and S. [RFC4033] Arends, R., Austein, R., Larson, M., Massey, D., and S.
Rose, "DNS Security Introduction and Requirements", Rose, "DNS Security Introduction and Requirements",
RFC 4033, March 2005. RFC 4033, March 2005.
[RFC4271] Rekhter, Y., Li, T., and S. Hares, "A Border Gateway [RFC4271] Rekhter, Y., Li, T., and S. Hares, "A Border Gateway
Protocol 4 (BGP-4)", RFC 4271, January 2006. Protocol 4 (BGP-4)", RFC 4271, January 2006.
[RFC4786] Abley, J. and K. Lindqvist, "Operation of Anycast [RFC4786] Abley, J. and K. Lindqvist, "Operation of Anycast
Services", BCP 126, RFC 4786, December 2006. Services", BCP 126, RFC 4786, December 2006.
10.2. Informative References 10.2. Informative References
[I-D.ietf-dnsop-as112-under-attack-help-help] [BIND] Internet Systems Consortium, "BIND",
Abley, J. and W. Maton, "I'm Being Attacked by <http://www.isc.org/software/BIND/>.
PRISONER.IANA.ORG!",
draft-ietf-dnsop-as112-under-attack-help-help-06 (work in
progress), April 2011.
[I-D.ietf-dnsop-default-local-zones]
Andrews, M., "Locally-served DNS Zones",
draft-ietf-dnsop-default-local-zones-15 (work in
progress), March 2011.
[RFC1876] Davis, C., Vixie, P., Goodwin, T., and I. Dickinson, "A [BINDGRAPH] Delaurenti, M. and M. d'Itri, "bindgraph",
Means for Expressing Location Information in the Domain <http://www.linux.it/~md/software/>.
Name System", RFC 1876, January 1996.
[RFC5735] Cotton, M. and L. Vegoda, "Special Use IPv4 Addresses", [DNSTOP] The Measurement Factory, "Dnstop: Stay on Top of Your
BCP 153, RFC 5735, January 2010. DNS Traffic",
<http://dns.measurement-factory.com/tools/dnstop/>.
[RFC5855] Abley, J. and T. Manderson, "Nameservers for IPv4 and IPv6 [DSC] The Measurement Factory, "Dsc: A DNS Statistics
Reverse Zones", BCP 155, RFC 5855, May 2010. Collector",
<http://dns.measurement-factory.com/tools/dsc/>.
URIs [QUAGGA] "Quagga Software Routing Suite",
<http://www.quagga.net>.
[1] <http://www.quagga.net/> [RFC1876] Davis, C., Vixie, P., Goodwin, T., and I. Dickinson, "A
Means for Expressing Location Information in the Domain
Name System", RFC 1876, January 1996.
[2] <http://www.isc.org/software/BIND/> [RFC5735] Cotton, M. and L. Vegoda, "Special Use IPv4 Addresses",
BCP 153, RFC 5735, January 2010.
[3] <http://www.linux.it/~md/software/> [RFC5855] Abley, J. and T. Manderson, "Nameservers for IPv4 and
IPv6 Reverse Zones", BCP 155, RFC 5855, May 2010.
[4] <http://dns.measurement-factory.com/tools/dnstop/> [RFC6303] Andrews, M., "Locally Served DNS Zones", BCP 163,
RFC 6303, July 2011.
[5] <http://dns.measurement-factory.com/tools/dsc/> [RFC6305] Abley, J. and W. Maton, "I'm Being Attacked by
PRISONER.IANA.ORG!", RFC 6305, July 2011.
Appendix A. History Appendix A. History
Widespread use of the private address blocks listed in [RFC1918] Widespread use of the private address blocks listed in [RFC1918]
followed that document's publication in 1996. At that time the IN- followed that document's publication in 1996. At that time the
ADDR.ARPA zone was served by root servers. IN-ADDR.ARPA zone was served by root servers.
The idea of off-loading IN-ADDR.ARPA queries relating to [RFC1918] The idea of off-loading IN-ADDR.ARPA queries relating to [RFC1918]
addresses from the root nameservers was first proposed by Bill addresses from the root nameservers was first proposed by Bill
Manning and John Brown. Manning and John Brown.
The use of anycast for distributing authoritative DNS service for The use of anycast for distributing authoritative DNS service for
[RFC1918] IN-ADDR.ARPA zones was subsequently proposed at a private [RFC1918] IN-ADDR.ARPA zones was subsequently proposed at a private
meeting of root server operators. meeting of root server operators.
ARIN provided an IPv4 prefix for the anycast service, and also the ARIN provided an IPv4 prefix for the anycast service and also the
autonomous system number 112 for use in originating that prefix. autonomous system number 112 for use in originating that prefix.
This assignment gave the project its name. This assignment gave the project its name.
In 2002 the first AS112 anycast nodes were deployed. In 2002, the first AS112 anycast nodes were deployed.
In 2011 the IN-ADDR.ARPA zone was redelegated from the root servers In 2011, the IN-ADDR.ARPA zone was redelegated from the root servers
to a new set of servers operated independently by AfriNIC, APNIC, to a new set of servers operated independently by AfriNIC, APNIC,
ARIN, ICANN, LACNIC and the RIPE NCC and named according to ARIN, ICANN, LACNIC, and the RIPE NCC and named according to
[RFC5855]. [RFC5855].
The use of anycast nameservers in the AS112 project contributed to The use of anycast nameservers in the AS112 project contributed to
the operational experience of anycast DNS services, and can be seen the operational experience of anycast DNS services, and it can be
as a precursor to the anycast distribution of other authoritative DNS seen as a precursor to the anycast distribution of other
servers in subsequent years (e.g. various root servers). authoritative DNS servers in subsequent years (e.g., various root
servers).
Appendix B. Change History
This section to be removed prior to publication.
00 Initial draft, circulated as draft-jabley-as112-ops-00 and
reviewed at the DNSOP working group meeting at IETF 66.
00 Document adoped by the DNSOP working group and renamed
accordingly.
01 Input from reviewers of DNSOP and others, some cosmetic tweaks.
02 Version bump as request by DNSOP chairs. Added missing IANA
Considerations section. Updated author's addresses. Make
http://www.as112.net/ URL consistent.
03 Fix BLACKHOLE-2.IANA.ORG IP address.
04 Bump version number. Refresh references. Add reference to BIRD.
Minor wordsmithing.
05 Updated following review from Peter Koch.
06 Updated following review from Alfred Hoenes.
07 Updated following IESG review.
08 Updated following review by S. Moonesamy.
09 Updated following review by Peter Koch.
Authors' Addresses Authors' Addresses
Joe Abley Joe Abley
ICANN ICANN
4676 Admiralty Way, Suite 330 4676 Admiralty Way, Suite 330
Marina del Rey, CA 90292 Marina del Rey, CA 90292
US US
Phone: +1 519 670 9327 Phone: +1 519 670 9327
Email: joe.abley@icann.org EMail: joe.abley@icann.org
William F. Maton Sotomayor William F. Maton Sotomayor
National Research Council of Canada National Research Council of Canada
1200 Montreal Road 1200 Montreal Road
Ottawa, ON K1A 0R6 Ottawa, ON K1A 0R6
Canada Canada
Phone: +1 613 993 0880 Phone: +1 613 993 0880
Email: wmaton@ryouko.imsb.nrc.ca EMail: wmaton@ryouko.imsb.nrc.ca
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