Feature #13296


Add support for DHCP6 OPTION_PD_EXCLUDE (RFC 6603)

Added by Michael Virgilio 12 months ago. Updated 11 months ago.

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Some ISPs are rolling out IPv6 and not directly providing a globally routable WAN address via DHCPv6. Instead, they are including a prefix delegation option that is used to exclude a prefix ID from being used internally, and using an address from that prefix ID for the WAN connection. This is documented in RFC 6603.

While there are ways to manually accomplish something similar using existing settings, such methods also require manual updating in the event that the prefix changes. As a result, external services relying on the WAN address (like VPN access) would be unavailable until such manual updating is done. Implementing this RFC would hopefully automate this process, eliminating some manual steps from being necessary in the event that the IPv6 prefix changes.

Obviously the prefix ID that is being excluded should also not be selectable for an internal network, and if someone has already configured a prefix ID that should be excluded (i.e. if the option changes in the future, or someone changes ISPs and the new ISP is excluding a network already configured), there should be some kind of notification of the conflict.


clipboard-202206221747-liyhm.png (29.2 KB) clipboard-202206221747-liyhm.png → luckman212, 06/22/2022 04:47 PM
Actions #1

Updated by → luckman212 12 months ago

I'm still hazy on exactly which dhcp6c implementation is currently shipping. I thought it was the hrs-allbsd/wide-dhcpv6, but the last commit there was ~2017. I found this in the src/dhcp6.c from DragonflyBSD ~2021, but I'm sure that would need some porting. Nothing indicates that the needed OPTION_PD_EXCLUDE (67) is supported in the version that we currently have (I hope I am wrong!)

It's mentioned in the 12.3 docs (search for "RFC 6603") but I just can't find it in the source code anywhere... guess I am looking in the wrong place.

Actions #3

Updated by → luckman212 12 months ago

Marcos M was that last link you posted supposed to show something related? for me it just appears to be a list of every single bug filed against the ports tree... ?

Actions #4

Updated by Marcos M 11 months ago

It's where the bug entries are for FreeBSD ports are, and where a feature request can be submitted.


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