gateway: change dns.listen default to [::1]:5353

The gateway is designed for systems already serving DHCP and DNS to
a LAN segment (canonically an OpenWrt AP). On those systems port 53
is already taken by the existing resolver, so the prior `[::]:53`
default conflicted with the gateway's intended deployment target out
of the box.

The OpenWrt ipk previously overrode this in its packaged config as a
workaround; matching the source default to what the canonical
deployment actually wants makes the override redundant and removes a
foot-gun for fresh manual Linux-host installs. The redundant
`dns.listen` line in `packaging/openwrt-ipk/files/etc/fips/fips.yaml`
is dropped along with this change.

Operators on a host without a pre-existing resolver on port 53 can
opt back into the wildcard bind by setting `dns.listen: "[::]:53"`
explicitly. The new default binds IPv6 loopback only — Linux IPv6
sockets bound to explicit `::1` do not accept v4-mapped traffic, so
forwarders that reach the gateway over IPv4 loopback need to be
pointed at an explicit IPv4 listen address instead.

Touches the gateway config struct and its default-value test, the
commented-out gateway example in the Debian common fips.yaml, the
OpenWrt ipk config (override removed), the gateway reference /
how-to / design / tutorial / troubleshoot docs, and a CHANGELOG
entry under [Unreleased] -> Changed.
This commit is contained in:
Johnathan Corgan
2026-05-08 14:02:05 +00:00
parent 9112c8f7f0
commit 0fcf0f6f8f
9 changed files with 77 additions and 47 deletions
+1 -1
View File
@@ -94,7 +94,7 @@ transports:
# pool: "fd01::/112"
# lan_interface: "eth0"
# dns:
# listen: "[::]:53"
# listen: "[::1]:5353"
# # upstream must match the daemon's dns.bind_addr above. The
# # default "[::1]:5354" matches the daemon's default. If you set
# # the daemon to bind on a wildcard ("::") or specific address,
@@ -76,16 +76,15 @@ peers: []
# Allows unmodified LAN hosts to reach FIPS mesh destinations via
# DNS-allocated virtual IPs and kernel nftables NAT.
#
# The gateway DNS listens on port 5353 by default so it does not conflict
# with dnsmasq on port 53. The init script configures dnsmasq to forward
# .fips queries to the gateway automatically.
# The gateway DNS listens on `[::1]:5353` by default (set in source) so it
# does not conflict with dnsmasq on port 53. The init script configures
# dnsmasq to forward .fips queries to the gateway automatically.
gateway:
enabled: true
pool: "fd01::/112" # virtual IP range (up to 65535 addresses)
lan_interface: "br-lan" # LAN-facing interface for proxy NDP
dns:
listen: "[::1]:5353" # gateway DNS listener (dnsmasq forwards here)
upstream: "[::1]:5354" # FIPS daemon DNS resolver (matches daemon default)
ttl: 60 # DNS TTL and mapping lifetime (seconds)
pool_grace_period: 60 # seconds after last session before reclaiming