Nerd blog.

13 Apr 2014

My IPv6 Services

I’ve had and its associated services IPv6 enabled over native IPv6 for the past year. Before that some services were IPv6 enabled over a tunnel.

Web services are the easiest I’d say, and were the first I implemented.

Web Services

Web services are pretty easy to IPv6 enable. NGINX makes configuration especially simple with multiple listen lines:

# HTTPS server
server {
	listen			443 ssl spdy;
	listen			[::]:443 ssl spdy;

Apache is similarly simple to configure. IPv4-in-IPv6 mapped addresses can make recognizing addresses a pain in your web applications sometimes. Complications have been fairly minimal, mainly with sessions that store the IP address. Privacy addressing, and switching between IPv6/v4 and back has caused occasional issues.


I run a typical Postfix/Dovecot system with Spamassassin and friends for mail. I have A and AAAA records for my mail server. The only complications I’ve had so far are:

  • Auto configured addresses don’t get revdns, and so auto configured addresses need to be disabled for mail servers (and servers in general, when source address matters for ACLs, QoS, etc)
  • Greylisting: when things fail over from IPv6 to IPv4, mail takes longer to get delivered.
  • Spam filtering is heavily built around IPv4 at the moment.


I run Prosody for XMPP services. Prosody is very simple compared with many other XMPP servers, and has had IPv6 support since 0.9.x (w/ Lua Socket 3.0).



Both of my internal DNS recursors are dual-stacked.


My network is not setup for IPv6 only access at the moment, I will be adding DNS64/NAT64 in the next few months to begin testing one translation method. Apparently my Cisco ASA 5505 running firmware 9.0/9.1 should be able to do NAT64/DNS64 w/ AAAA synthesis.


At the moment only one of my nameservers is dual-stacked, the rest are only IPv4 enabled.

| => check-soa -i OK: 2014040601 (4 ms)
	2604:4280:0:1::53: OK: 2014040601 (5 ms) OK: 2014040601 (73 ms) OK: 2014040601 (6 ms)

Theodore Baschak - Theo is a network engineer with experience operating core internet technologies like HTTP, HTTPS and DNS. He has extensive experience running service provider networks with OSPF, MPLS, and BGP.