From 81075203a057c9ba3467a7f90ea1e9469d7f7723 Mon Sep 17 00:00:00 2001 From: Colin Percival Date: Mon, 22 Nov 2021 20:16:34 -0800 Subject: [PATCH] EC2: Turn off IPv6 DAD Disable Duplicate Address Detection in EC2 instances. The networking configuration in EC2, with IPv6 addresses assigned by DHCPv6 and host egress filtering, makes "duplicate addresses" impossible. This speeds up the boot process in EC2 by 2 seconds. Reviewed by: kp, imp, bz MFC after: 2 weeks Sponsored by: https://www.patreon.com/cperciva Differential Revision: https://reviews.freebsd.org/D33091 --- release/tools/ec2.conf | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/release/tools/ec2.conf b/release/tools/ec2.conf index 2bf47b01077d..f0665646088b 100644 --- a/release/tools/ec2.conf +++ b/release/tools/ec2.conf @@ -70,6 +70,10 @@ vm_extra_pre_umount() { echo 'rtsold_enable="YES"' >> ${DESTDIR}/etc/rc.conf echo 'rtsold_flags="-M /usr/local/libexec/rtsold-M -a"' >> ${DESTDIR}/etc/rc.conf + # Turn off IPv6 Duplicate Address Detection; the EC2 networking + # configuration makes it unnecessary. + echo 'net.inet6.ip6.dad_count=0' >> ${DESTDIR}/etc/sysctl.conf + # Provide a script which rtsold can use to launch DHCPv6 mkdir -p ${DESTDIR}/usr/local/libexec cat > ${DESTDIR}/usr/local/libexec/rtsold-M <<'EOF'