IPv6 (again)

By DaveAtFraud - Posted on 15 October 2012

So, it's been a year and a half since I last did anything with IPv6. Lots of life has happened since then but technology marches on. After upgrading my gateway/DNS/firewall/router to Scientific Linux 6.3, I have been deluged with DNS errors because IPv6 addresses aren't resolvable on my system. I guess that's an indication that I really should pick back up on getting IPv6 working.

My plan is to do a phased roll-out of IPv6 with the first phase being to just get it working alongside my existing IPv4 network. That means setting up DHCP6 and DNS for internal systems and then getting local services like amanda, NTP and NFS to work with either protocol. Once I get to that point, I'll see if I can get an IPv6 tunnel working again but this time as a gateway.

Update 31 May 2013: Here's a hint at how things are going...

ipv6 ready

Lots of progress so lots of updates to come but it's basically working. Still can't get reverse DNS to work for DHCP assigned addresses and dhcp6d and dhcpd seem to not be able to coordinate updates to files like /etc/resolv.conf but those are details for future postings. The body of this post (from the summary break, on) has not yet been updated.

Random record of changes:

[root@fraud network-scripts]# cat ../network

[root@fraud network-scripts]# cat /etc/sysctl.conf
# Kernel sysctl configuration file for Red Hat Linux
# For binary values, 0 is disabled, 1 is enabled. See sysctl(8) and
# sysctl.conf(5) for more details.

# Controls IP packet forwarding
net.ipv4.ip_forward = 1

# Controls source route verification
net.ipv4.conf.default.rp_filter = 1

# Do not accept source routing
net.ipv4.conf.default.accept_source_route = 0

# Controls the System Request debugging functionality of the kernel
kernel.sysrq = 0

# Controls whether core dumps will append the PID to the core filename.
# Useful for debugging multi-threaded applications.
kernel.core_uses_pid = 1

# Controls the use of TCP syncookies
net.ipv4.tcp_syncookies = 1

# Disable netfilter on bridges.
net.bridge.bridge-nf-call-ip6tables = 0
net.bridge.bridge-nf-call-iptables = 0
net.bridge.bridge-nf-call-arptables = 0

# IPv6

net.ipv6.conf.all.accept_ra = 0
net.ipv6.conf.all.autoconf = 0

# Controls the default maxmimum size of a mesage queue
kernel.msgmnb = 65536

# Controls the maximum size of a message, in bytes
kernel.msgmax = 65536

# Controls the maximum shared segment size, in bytes
kernel.shmmax = 68719476736

# Controls the maximum number of shared memory segments, in pages
kernel.shmall = 4294967296

Downloaded and did a chkconfig on for radvd. Still need to configure it.