Last night I had my provider (Linode) add IPv6 support for my server. I also had them assign me an IPv6 pool to use.

I have Nginx 1.0.2 compiled with IPv6 support, restarted my Nginx and everything was fine all night and most of the morning. However, within minutes of me adding AAAA records to my domains, Nginx stopped and running and took the IPv4 networking down with it. I hadn't even restarted Nginx after adding the records.

Upon reboot with Nginx disabled, everything runs fine. I start Nginx and make a single IPv4 page request, the network is completely gone again on all ports.

I don't believe in coincidences so what could adding AAAA records to domains Nginx is listening for on port 80 trigger? Nginx had been running without problems for 12 hours with IPv6 enabled on the server with an assigned global scope IPv6 address. Within minutes of me adding those AAAA records, the trouble began.

I don't see anything in the logs that helps. Here is my configuration for Nginx:

nginx: configure arguments:
--sbin-path=/usr/sbin/nginx
--conf-path=/etc/nginx/nginx.conf
--user=nginx
--group=nginx
--http-client-body-temp-path=/var/lib/nginx/tmp/client_body
--http-proxy-temp-path=/var/lib/nginx/tmp/proxy
--http-fastcgi-temp-path=/var/lib/nginx/tmp/fastcgi
--error-log-path=/var/log/nginx/error.log
--http-log-path=/var/log/nginx/access.log
--prefix=/usr/share/nginx
--pid-path=/var/run/nginx.pid
--add-module=../headers-more-nginx-module
--add-module=../ngx_http_redis-0.3.1
--add-module=../ngx_http_upstream_keepalive
--add-module=../memc-nginx-module
--add-module=../ngx_cache_purge
--add-module=/usr/local/rvm/gems/ruby-1.9.2-p0@rails3/gems/passenger-3.0.2/ext/nginx
--add-module=../ngx_http_log_request_speed
--add-module=../mod_strip
--with-ipv6
--with-http_ssl_module
--with-http_gzip_static_module
--with-http_xslt_module
--with-http_image_filter_module
--with-http_geoip_module
--with-http_sub_module
--with-http_realip_module
--with-http_stub_status_module
--with-http_flv_module
--without-mail_pop3_module
--without-mail_imap_module
--without-mail_smtp_module
--without-select_module
--without-poll_module
--with-openssl=../openssl-1.0.0d
--with-pcre=../pcre-8.12
--with-zlib=../zlib-1.2.5
--with-cpu-opt=Xeon
--with-cc-opt='-pipe -s -O3 -Wall -Wp,-D_FORTIFY_SOURCE=2 -fexceptions -fstack-protector --param=ssp-buffer-size=4 -mmmx -msse -msse2 -msse3 -mfpmath=sse -mtune=native -march=native -enable-new-dtags -DNODEBUG -DNDEBUG -enable-stdcall-fixup -frerun-loop-opt -ftracer'