slow dhcp on wan -> broken NAT

Started by synfinatic, July 25, 2026, 07:47:57 PM

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July 29, 2026, 02:34:36 PM #30 Last Edit: July 29, 2026, 02:39:40 PM by drosophila
Thanks for the clarifications! Initially I got my hopes up that I might be able to use this to get rid of the autogenerated LLA and also get an interface that exclusively receives Privacy Extension addresses. However, at least the latter will probably not work since PE depends on SLAAC and that will automatically give me ULA/GUA addresses on the respective interface that I'd then have to manually separate regardless. Thus I'd still need a script and then it wouldn't change the general situation. :)

Regarding promiscuous mode it would be odd to have attacks through this, since the upstream node will certainly use a switch, so an attacker would have to know your MAC, and even if they do, the likelihood of someone using promiscuous mode without having set up a tight firewall is too low to bother for any common criminal. High-profile criminals like NSA or similar insecurity agencies would be the only ones with sufficient budget and determination if you ended up on their hit-list for criticizing their respective "beloved leader" or say something they don't like.

I just upgraded to the latest and other than system not rebooting automatically after the upgrade, at least this time NAT worked correctly after it got a DHCPv4 lease and IPv6 egress worked correctly once I got a my delegation via DHCPv6.

I'm pretty sure the trick is to go: Firewall -> NAT -> Outbound

And then for every source network, change the NAT Address from `Interface address` to the actual interface name (in my case `ONTWAN address`) listed in Interfaces that you have configured to get an address via DHCPv4.