IPv6 Applications

1
IPv6 Applications

• Stig Venaas
• venaas_at_uninett.no
• UNINETT/University of Southampton
• Parts by David Mills, dgm_at_ecs.soton.ac.uk

2
Overview

• Available IPv6 applications
• Some IPv6 application issues
• Where to learn more

3
Some basic applications

• Many FTP servers are IPv6 enabled, ProFTPD is one
  of the more well known
• There are also many IPv6 enabled FTP clients
  (lftp, tnftp, cftp) including the IPv6 enabled
  web browsers
• Many systems are shipped with IPv6 enabled
  telnet, ssh, ftp etc, including BSD, Solaris and
  several Linux distributions
• IPv6 enabled systems have ping, traceroute,
  tracepath etc. Sometimes named ping6,
  traceroute6, tracepath6,

4
HTTP

• Apache2
• Listen or Listen 80. Complete
  support, virtual hosts, ACLs etc are working
• Mozilla, Firefox, Explorer, Opera, Konqueror,
  Lynx,
• ffproxy at http//faith.eu.org/programs.html
• A web proxy that supports both v4 and v6. This
  should allow an IPv4-only or IPv6-only host or
  browser to reach a v4-only or v6-only server
• Can also be used as an accelerator (front-end to
  webserver) so that your server appears to be
  dual-stack when it isnt

5
SMTP

• Sendmail has IPv6 as standard
• Must be enabled in M4 file
• Postfix with patch
• Exim
• Has IPv6 but I believe it must be enabled at
  compile time
• No problem with having MXes with IPv6, but might
  be good to have a last resort MX with IPv4-only
  in case of broken MTAs
• See RFC 3974

6
SSH

• At least OpenSSH (http//www.openssh.org/) and
  Sun_SSH (delivered with Solaris) supports IPv6
• SSH tunneling
• If one has say IPv4-only IMAP client and server,
  one can tunnel the IMAP connection through SSH
  and SSH session might be IPv6. In this way one
  only sends IPv6 packets on the network even if
  applications use IPv4.

7
More applications

• OpenLDAP
• IPv6 enabled LDAP server and clients
• Other LDAP application becomes IPv6 enabled when
  using OpenLDAP client libraries
• There is also Sun ONE Directory server with IPv6
• GnomeMeeting
• H.323 VoIP and videoconferencing. Supports IPv6
  and runs on at least Linux. http//www.gnomemeetin
  g.org/
• Kphone
• IPv6 enabled VoIP SIP based softphone
• http//www.iptel.org/products/kphone/

8
Multicast capable applications

• Mbone tools, vic/rat etc
• IPv6 multicast conferencing applications
• http//www-mice.cs.ucl.ac.uk/multimedia/software/
• VideoLAN
• Video streaming, also IPv6 multicast. Server and
  client
• Many operating systems, both Windows and UNIX
• http//www.videolan.org/
• DVTS http//www.sfc.wide.ad.jp/DVTS/
• Streaming DV over RTP over IPv4/IPv6
• DV devices using Firewire can be connected to two
  different machines and you can stream video
  between them over the Internet
• Mad flute
• Streaming of files using multicast (IPv4/IPv6
  ASM/SSM)
• Linux and Windows (not totally sure about BSD
  status)
• http//www.atm.tut.fi/mad/

9
Globus Toolkit

• The Globus Toolkit is an open source software
  toolkit used for building grid applications
  http//www-unix.globus.org/toolkit/
• The toolkit is comprised of services, based on
  WS-RF
• It runs in both a Windows and UNIX environment
• Its current stable version is 3.2.1 though
  version 4 is in alpha release. Both versions have
  been ported to use IPv6 through work done by UCL
  and UoS
• Details of enabling IPv6 within Globus can be
  found at http//www.cs.ucl.ac.uk/staff/sjiang/webp
  age/How-to-IPv6- in-GT4.htm

10
AccessGrid

• AccessGrid is a multi venue conferencing
  application, that allows sharing of data,
  launching of shared applications between the
  users and has a built-in text chat facility
• http//www-unix.mcs.anl.gov/fl/research/accessgrid
  /
• It uses VIC and RAT multicast streams to
  transport the media between the server and
  clients
• The Globus Toolkit provides security within
  AccessGrid through means of proxy certificates
• Work is currently under way at UCL and UoS to
  enable an IPv6 capable version
• Also an IPv6 to IPv4 proxy is being constructed
  that incorporates a multicast gateway

11
IPv6-enabled services at U of Southampton

• Web site(s) (Apache2)
• Login/FTP (ssh, sftp)
• DNS (bind9)
• SMTP (sendmail)
• RADIUS (Radiator)
• NTP (TTM, Meinberg)
• RIPE TTM server
• Nagios
• MRTG
• Snort

• Jabber
• IRC
• Open.H323
• SIP-based VoIP (SER)
• Video streaming (uc/mc)
• Radio streaming (uc/mc)
• Tunnel broker
• 6to4 relay

12
Some application issues

• The same binary should work on hosts that support
  only one or both IP protocols
• Applications must be changed to use IPv6 socket
  APIs (RFC 3493 and RFC 3542)
• Applications should try all addresses (both v4
  and v6) they get from DNS if necessary.
  Applications should use the getaddrinfo()
  resolver function and try the addresses in the
  order it returns them often IPv6 first. Some
  applications fail to failover to IPv4 when IPv6
  fails
• May result in long timeouts. Might wait up to 30s
  per address if no TCP/ICMP error
• Also some firewalls just discard DNS packets with
  AAAA requests, resulting in long timeout,
  ad.doubleclick.net is one problem
• IPv6 addresses in URLs (RFC 2732)
• E.g. http//2001610148dead21018fffe02e38
  80/
• Not all applications support this
• IPv4 mapped IPv6 addresses
• Some operating systems allow applications to
  send/receive IPv4 on IPv6 sockets
• An IPv4 address a.b.c.d is represented as
  ffffa.b.c.d
• Some poorly written applications may require you
  to write IPv6 ACLs for mapped addresses to limit
  IPv4

13
Some programming languages

• Perl
• Special modules like Socket6 and
  IOSocketINET6
• Python 2.3.4 works with IPv6
• However, Windows binaries at python.org does not
  support it. 2.4 binaries will be built with IPv6
  support
• PHP
• Partial IPv6 support
• Many PHP scripts work with IPv6 with no change
• Java
• SUN Java SDK 1.4 has IPv6 support
• Many Java applications work with IPv6 with no
  change due to the higher level API

14
Application programming/issues

• Address-family independent socket programming for
  IPv6
• http//www.ipv6.or.kr/summit2003/presentation/II-2
  .pdf
• Porting applications to IPv6 HowTo
• http//gsyc.escet.urjc.es/eva/IPv6-web/ipv6.html
  
• Application Aspects of IPv6 Transition
• http//www.ietf.org/internet-drafts/draft-ietf-v6o
  ps-application-transition-03.txt
• Guidelines for IP version independence in GGF
  specifications
• http//www.ggf.org/documents/GWD-I-E/GFD-I.040.pdf
  
• IPv6 Forum Programming and Porting links
• http//www.ipv6forum.org/modules.php?opmodloadna
  meWeb_Linksfileindexreqviewlinkcid56
• Books
• IPv6 Network Programming by Jun-ichiro itojun
  Hagino
• UNIX Network Programming (latest version) by W.
  Richard Stevens

15
IPv6 application pointers

• Very good list of applications
• http//www.deepspace6.net/docs/ipv6_status_page_ap
  ps.html
• IPv6 Application and Patch Database
• This also has searchable interface
• http//6net.iif.hu/ipv6_apps/
• 6NET applications
• http//apps.6net.org/WP5Apps/Applications.html