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IETF!93!Review


30st!July!2015
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before!we!start
…!please!note:!BIND!9!security!issue!
!
CVE-2015-5477:!An!error!in!handling!TKEY!
queries!can!cause!named!to!exit!with!a!REQUIRE!
assertion!failure!
all!BIND!9!DNS!Server!should!be!updated!to!the!
latest!9.10.2-P3!or!9.9.7-P2!versions!
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Agenda
IETF!93!in!Prague!!
DNS,!DNSSEC,!DANE,!DHCP,!IPv6!
the!following!information!is!an!excerpt!of!the!IETF!
working!group!activities!
for!a!full!overview!of!all!activities!at!IETF!93,!see!

https://datatracker.ietf.org/meeting/93/materials.html
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DNS
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new!DNS!related!RFCs!

published!since!last!IETF
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RFC Title Category
7505
A "Null MX" No Service Resource Record for Domains That
Accept No Mail
Standards Track
7534 AS112 Nameserver Operations Informational
7535 AS112 Redirection Using DNAME Informational
7553
The Uniform Resource Identifier (URI) DNS Resource
Record
Informational
7558
Requirements for Scalable DNS-Based Service Discovery
(DNS-SD) / Multicast DNS (mDNS) Extensions
Informational
©!Men!&!Mice!!http://menandmice.com!
RFC!7505!-!

A!"Null!MX"!No!Service!Resource!Record!for!Domains!
That!Accept!No!Mail
sending!mail!server!will!lookup!MX-Records!for!the!
recipients!domain,!without!MX!it!will!fallback!to!A/
AAAA-Address!records!
the!"null!MX"!record!indicates!that!a!host/domain!
cannot!receive!SMTP!mail!
Example:!
www.menandmice.com. 3600 IN MX 0 .
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RFC!7553

The!Uniform!Resource!Identifier!(URI)!DNS!Resource!
Record
maps!a!service!name!and!a!domain!to!an!Uniform!
Resource!Identifier!(URI)!
similar!to!SRV,!but!returns!a!full!URI!instead!
hostname!+!port!
Example:!
_http._tcp.menandmice.com. 3600 IN URI 10 50 "http://www.menandmice.com"

_http._tcp.menandmice.com. 3600 IN URI 10 50 "http://www.menandmice.com"

_http._tcp.menandmice.com. 3600 IN URI 20 00 "http://www.menandmice.com"
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priority
weight
URI
©!Men!&!Mice!!http://menandmice.com!
DNS!Transport!over!TCP!-!Implementation!Requirements

draft-ietf-dnsop-5966bis
update!of!RFC!5966!
make!TCP!a!requirement!for!the!DNS!protocol!
Benefits!of!DNS!over!TCP:!
•!prevents!amplification!attacks!
•!privacy/encryption!(TLS)!
•!no!fragmentation!issues!
Clients!should!pipeline!their!queries!over!TCP!
with!keep-alive,!persistent!connections!and!pipelining,!
DNS!over!TCP!can!be!as!fast!as!traditional!DNS!over!UDP
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The!edns-tcp-keepalive!EDNS0!Option!
draft-ietf-dnsop-edns-tcp-keepalive
it!is!expected!to!see!more!DNS-TCP!traffic!in!the!
future!
enables!DNS!clients,!DNS!resolver!and!authoritative!
DNS-Server!to!negotiate!a!keep!alive!for!TCP!
sessions!
clients!can!send!multiple!queries!over!an!
established!TCP!session!
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KSK!rollover!in!the!root-zone
the!Internet!DNS!root!zone!has!been!signed!5!years!
ago!(July!2010)!
the!root!KSK!should!be!rolled!
•HSMs!are!getting!old!and!out!of!support!
several!issues!have!been!identified:!
•the!publication!format!of!the!KSK!trust!anchor!is!not!standardised!
•(secure)!bootstrapping!of!DNSSEC!DNS-resolvers!
•devices!might!"miss"!the!KSK!roll!(via!RFC!5011)!while!being!"on!the!
shelf",!no!standard!way!to!re-bootstrap
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Yeti-DNS!project
experimental,!IPv6!only!DNS-root-server

system!
Large-scale!testbed!
Yeti!Participants:!
•!Operators!of!Yeti!components,!or!experimenters!
•!DNS!experts,!with!varied!backgrounds!and!interests
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Yeti-DNS!project
Planned!Experiments!&!Other!Investigations!
•Impacts!of!IPv6-only!DNS!
•Bigger!minimum!packet!size,!no!IP-fragmentation!
•KSK!rollover,!KSK/ZSK!rollover!frequency,!algorithm,!signature!size!
•Changes!in!DNSSEC!
•Changes!to!root!servers

Lots/few!of!root!servers,!churn!in!root!server!set!
the!project!is!looking!for!volunteers!

running!DNS!resolvers!against!

the!Yeti-DNS!root!(informed!users!

in!non-critical!environments)
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http://yeti-dns.org/
©!Men!&!Mice!!http://menandmice.com!
RFC!6761!"special!use!domain-names"
request!for!Special!Use!Domain!Names!of!P2P!
Systems:!
•!!.bit!=!Namecoin!
•!!.exit!=!Tor!Project!
•!!.gnu!and!.zkey!=!GNUnet!
•!!.i2p!=!I2P!System!
•!!.tor!=!consensus!among!Tor!routes
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RFC6761bis!Problem!Space

Input!to!the!Design!Team
future!of!the!special!names!registry!
namespace!!=!DNS!
one-off!protocol!switch!or!general!solution!
(.alt,!.ext,!.external)?!
separate!protocol!design!from!policy?!
heated!debate!during!IETF!93,!no!conclusions,!
discussion!will!continue!on!the!mailing!list(s)
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DANE
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A!DANE!Record!and!DNSSEC!Authentication!Chain!
Extension!for!TLS

!draft-shore-tls-dnssec-chain-extension
new!TLS!extension!for!transport!of!a!DNS!record!set!
serialised!with!the!DNSSEC!signatures!needed!to!
authenticate!that!record!set!
•without!performing!perform!additional!DNS!record!lookups!
(latency)!
•avoid!potential!problems!with!TLS!clients!being!unable!to!
look!up!DANE!records!
•allows!a!TLS!client!to!validate!DANE!records!itself!without!a!
validating!DNS!resolver
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A!DANE!Record!and!DNSSEC!Authentication!Chain!
Extension!for!TLS

!draft-shore-tls-dnssec-chain-extension
the!TLS!client!requests!the!DNSSEC!validation!chain!
be!returned!
the!server!performs!the!appropriate!DNS!queries,!
builds!the!validation!chain,!and!returns!it!to!the!
client!(as!part!of!the!TLS!handshake)!
The!client!then!authenticates!the!chain!using!a!pre-
configured!trust!anchor!
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Client!Certificates!in!DANE!TLSA!Records

draft-huque-dane-client-cert
extension!to!the!existing!TLSA!record!
_smtp-client.device1.example.com. IN TLSA (

3 1 1 d2abde240d7cd3ee6b4b28c54df034b9

7983a1d16e8a410e4561cb106618e971 )
•Client!has!an!identity!assigned!corresponding!to!a!DNS!domain!
name.!!
•Client!has!a!private/public!key!pair!and!a!certificate!binding!the!
domain!name!to!the!public!key.!!
•Domain!Name!+!Certificate!has!a!corresponding!signed!DNS!
TLSA!record!
•a!new!TLS!extension!is!proposed!to!convey!the!DNS!client!identity
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SMIMEA!and!OPENPGPKEY
Discussion!of!how!to!store!the!key!holders!email!
address!
! hash!vs.!base32!
no!consensus!reached!during!the!meeting,!discussion!on!
the!mailing!list!until!1st!of!August!
seperator!label!"_at"!proposed!instead!of!"_smimecert"!
and!"_openpgpkey"!
Working!Group!Last!Call!(WGLC)!planned!before!IETF!94!
(November)!
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DPRIVE
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DNS!over!DTLS!

draft-ietf-dprive-dnsodtls
•Advantages!
•avoid!head-of-line!blocking!
•fast!session!resumption!
•supports!Anycast!
•Problems!
•DPI!Firewalls!->!use!different!port!for!DNS/DTLS!
•DNS!Server!authentication!->!x509!cert!
•private!server!do!not!have!CA!certs!->!self-signed!cert!fingerprint!
•configured!in!/etc/resolv.conf!(or!similar)!
•!discovery!of!DNSoD!->!downgrade!attack!possible
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TCP-TLS!for!DNS
•!discussion!about!no!STARTTLS!
•consensus:!use!new!port!for!DNS!over!TLS!
•DNS!over!TLS!should!follow!TLS!BCP!(best!current!practice)!
document!
•available!implementations:!!
•Unbound!
•ldns/drill!
•digit!
•getdns-api
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IPSec!AUTH_NULL!opportunistic!DNS
•client!to!resolver!path!encryption!
•why!not!encrypt!all!traffic!instead!of!only!DNS?!
•IPSec!encryption!without!authentication!
•coffee-shop!scenario!
•optionally!limited!to!DNS!traffic!only!
•proposed!alternative!to!"in-DNS-protocol"!solution!
•already!available!and!working!with!current!implementations
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DHCP
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©!Men!&!Mice!!http://menandmice.com!
published!new!RFCs!since!last!IETF
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RFC Title Category
RFC 7550 Issues and Recommendations with Multiple Stateful DHCPv6 Options Standards Track
©!Men!&!Mice!!http://menandmice.com!
Update!!of!Secure!DHCPv6!
&!Secure!!DHCPv4
draft-ietf-dhc-sedhcpv6!
draft-jiang-dhc-sedhcpv4!
DHCPv6!client/server!authentication!mechanism!
based!on!sender's!public/private!key!pairs!
!!!or!certificates!with!associated!private!keys!
IETF!hackathon!did!an!(successful)!interoperability!
test!of!two!implementations!(ISC!KEA!and!WIDE!
DHCPv6,!support!for!ISC!DHCP!is!"work!in!progress")
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DHCP!Anonymity!Profile
draft-ietf-dhc-anonymity-profile!
DHCPv4!and!DHCPv6!clients!disclose!many!identifiers!that!can!be!used!to!track!
clients.!This!work!seeks!to!eliminate!that!information!leak!by!defining!an!
anonymity!profile,!a!set!of!DHCP!behaviours!
•Randomising!MAC!address!+!client-id/DUID!
•Not!disclosing!client!hostname!
•Changing!identity!
•Limiting!information!disclosure!when!changing!networks!
Prototype!implementation:!Windows!10!(Microsoft)!
! implementation!choice:!does!not!send!hostname!option!
Microsoft!did!a!field!trial!using!the!prototype!implementation,!only!minor!issues!
found
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DHCP!v4/v6!Relay!Initiated!Release
draft-gandhewar-dhc-relay-initiated-release-00!
draft-gandhewar-dhc-v6-relay-initiated-release-00!
Issue:!clients!sometimes!do!not!release!a!lease!when!leaving!the!network!
(in!some!networks)!the!DHCP!lease!is!used!to!keep!state!beyond!the!IP-
address:!
•various!routes!e.g.!access,!framed!routes!
•various!services!e.g.!data,!voice,!video!
•policy!
•QoS!setup!
DHCP!relay!might!be!able!to!detect!client!leaving,!releasing!the!lease!on!
behalf!of!the!client
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IPv6/IPv4-sunset
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published!new!RFCs!since!last!IETF
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RFC Title Category
RFC 7445 Analysis of Failure Cases in IPv6 Roaming Scenarios Informational
RFC 7506
IPv6 Router Alert Option for MPLS Operations, Administration, and
Maintenance (OAM)
Standards Track
RFC 7526 Deprecating the Anycast Prefix for 6to4 Relay Routers
Best Current
Practice
RFC 7527 Enhanced Duplicate Address Detection Standards Track
RFC 7559 Packet-Loss Resiliency for Router Solicitations Standards Track
RFC 7600 IPv4 Residual Deployment via IPv6 - A Stateless Solution (4rd) Experimental
RFC 7608 IPv6 Prefix Length Recommendation for Forwarding
Best Current
Practice
©!Men!&!Mice!!http://menandmice.com!
IPv6!to!"internet!standard"
RFC!2460

(and!many!other

RFCs!are!still!a!

"draft!standard"!
•RFC!6410!"Requirements!for!Internet!Standards"!
•!forward!"draft"!to!"proposed!standard"!
•!WG!discussion!of!"re-write!update!RFC!vs.!pushing!
RFC!unchanged"
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Randomised!MAC!Addresses!and!

IPv6!Address!Assignment
enhance!privacy!of!users!
•users!can!hide!from!the!network!
•prevent!location!tracing!
•implemented!using!standard!IEEE!802!rules!(Preferred!!Format:!
U/L=1,!G=0,!46!random!bits)!
•!conflict!with!RFC!7217!(A!Method!for!Generating!Semantically!
Opaque!Interface!Identifiers!with!IPv6!Stateless!Address!Auto-
configuration!(SLAAC))!
•!conflict!with!SAVI!"Source!Address!Validation!Improvement!
(SAVI)!Solution!for!DHCP"
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©!Men!&!Mice!!http://menandmice.com!
IPv6!news!from!Apple
all!iOS!apps!MUST!support!native!IPv6!(starting!
with!iOS!9)!
Happy!Eyeballs!in!iOS!9!and!MacOS!X!10.11!will!
prefer!IPv6!99%!of!the!time!
NAT64!internet!sharing!uses!2001::/64!(Teredo!
prefix)
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IPv6!news!from!Apple
NAT64/DNS64!"IPv6-only"!network!via!MacOS!X!
Internet!Sharing!in!MacOS!X!10.11!"El!Capitan"



NAT64/DNS64!

can!break!local!

DNSSEC!

validation!!
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Some!Design!Choices!for!IPv6!
Networks
draft-ietf-v6ops-design-choices!
includes!now!Enterprise!environments!and!their!use!
cases!(in!addition!to!service!providers)!
new!IGP!choice!section!
!now!covers!EIGRP!and!RIPng!
new!section!on!address!choices
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©!Men!&!Mice!!http://menandmice.com!
draft-yc-v6ops-solicited-ra-unicast
multicast!router!advertisements!in!large!wireless!networks!
•every!device!joining!the!network!sends!a!router!solicitation!
•router!sends!multicast!RA,!all!devices!in!the!network!awake!
•drains!device!battery!
Recommendations!
•Router!manufacturers!SHOULD!allow!network!administrators!to!
configure!the!routers!to!respond!to!Router!Solicitations!with!unicast!
Router!Advertisements.!
•Networks!that!serve!large!numbers!(tens!or!hundreds)!of!mobile!
devices!SHOULD!enable!this!behaviour.
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Host!address!availability!recommendations

draft-colitti-v6ops-host-addr-availability
Addressing!practices!that!make!sense!in!IPv4!may!not!be!
appropriate!in!IPv6!
•/64!per!link!allows!“unlimited”!host!addressing!
•No!longer!forced!to!assign!one!address!per!host!due!to!address!scarcity!
•Many!benefits!provided!by!assigning!multiple!addresses!to!each!host!
Recommendations!
•Provide!multiple!IPv6!addresses!from!each!prefix!to!general-purpose!hosts!
when!they!attach!to!the!network!
•Don’t!impose!a!hard!limit!on!the!size!of!the!address!pool!assigned!to!a!host!
•If!the!network!requires!explicit!requests,!assign!a!/64!via!DHCPv6!PD
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RFC!7511

Scenic!Routing!for!IPv6
•incorporates!the!green-ness!of!

a!network!path!into!the!routing!

decision!
•routing!algorithms!SHOULD!!

calculate!the!optimal!paths!providing!

the!most!fresh-air!time!for!a!packet!
•should!therefore!choose!paths!based!on!

Avian!IP!Carriers![RFC1149]!and/or!wireless!technologies!
room!for!"live"!implementation:!CCC!Camp!

13-17!Aug!2015!https://events.ccc.de/camp/2015/wiki/Main
38
Zelte!und!ein!„Datenklo“!auf!dem!Chaos!Communication!Camp,!Finowfurt!2007!
"RobotSkirts"/Eliot!Phillips,!CC-by-sa-2.0
©!Men!&!Mice!!http://menandmice.com!
don't!miss!our!next!webinar
•"PowerDNS",!Monday,!31st!August!2015!
•overview:!the!PowerDNS!open!source!DNS!server!
•manage!a!DNS!zone!via!SQL!backend!
•manage!a!DNS!zone!via!BIND!backend!
•remote!zone!Backend!
•DNSSEC!signing!with!PowerDNS!
•the!Men!&!Mice!Suite!controller!for!PowerDNS!
•Signup!@!

https://www.menandmice.com/resources/educational-resources/webinars/
39
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upcoming!Men!&!Mice!trainings
•Upcoming!Trainings:!
•September!8!–!11,!2015,!Special!4!days:!IPv6!Introduction!+!Advanced!Topics!Hands-On!
Workshop,!San!Francisco!area!(CA),!USA!!
•September!28!–!29,!2015,!Introduction!to!DNS!&!BIND!Hands!on,!Arlington!(VA),!USA!
•September!30!–!October!2,!2015,!DNSSEC!Technical!Workshop!–!Implementation!and!
Deployment,!Arlington!(VA),!USA! !
•September!28!–!October!2,!2015,!Introduction!&!Advanced!DNS!and!BIND!Hands!on,!
Arlington!(VA),!USA!
•November!16!–!17,!2015,!Introduction!to!DNS!&!BIND!Hands!on,!Redwood!City!(CA),!USA!
•November!16!–!20,!2015,!Introduction!&!Advanced!DNS!and!BIND!Hands!on,!Redwood!City!
(CA),!USA



more!training!classes!on!

!!!!https://www.menandmice.com/support-training/training/
40
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Q/A
41
?
2015!Schedule,!Slides,!Links,!Recording!and!errata!
can!be!found!@

https://www.menandmice.com/resources/educational-resources/webinars/

IETF 93 Review Webinar