
UDP multicast subscriptions inside the network namespace will see the unmodified pre-NETMAP 192.168.0.x source addresses.

The actual topic of this question is that there's a weird glitch in the NETMAP source IP adjustment that I haven't been able to explain, only work around. Ns1 example smcrouted config rules for a supported multicast group: mgroup from eth1 group 239.255.60.60 Ns1 example NETMAP rules for the static IP subnets: sudo -n ip netns exec ns1 iptables -t nat -A PREROUTING -d 192.168.1.0/24 -i peer1 -j NETMAP -to 192.168.0.0/24 To try to visualise the traffic flows: embedded network

a separate Linux network namespace for each different embedded network (call them ns1, ns2, etc).

network links for each embedded network (call them eth1, eth2, etc).This mostly works fine, including for UDP multicast traffic, given: In an embedded/IoT use case, I have a management host running Linux that needs to be able to talk to multiple networks that each use a common set of static IP addresses.
