Hello, I have googled for how to select a specific source among a number of candidates, and have found two recommended ways based on RFC3484: 1) set the preferred address with a /128 mask on the outgoing interface 2) deprecate all other equal or better addresses by setting the preferred lifetime to 0 However, none of these can be used if the preferred address is coming from a prefix delegated via DHCPv6-PD, and the uplink/WAN interface is supposed to have a dynamically assigned (SLAAC) global address. This is my situation. RFC3633 forbids using any part of the delegated prefix for the uplink/WAN interface: "the requesting router MUST NOT assign any delegated prefixes or subnets from the delegated prefix(es) to the link through which it received the DHCP message from the delegating router." so option 1) is out of the question. And I believe there is no way to deprecate a dynamically assigned address. You can deprecate it, but the status will change with the next RA received, so option 2) is out of the question as well. So I looked for other options in RFC3484 and found that setting the "home" flag on the preferred source address does indeed work, without needing to change anything on the outgoing interface. So it looks like an excellent way to mark the preferred source address, completely ignoring outgoing interface and prefix lengths. However, I wonder if this has any unwanted side effects? Exactly what is this flag changing? Or is it just a flag, which only affects address selection? Note: I do not use mobile IPv6, so there is no chance that this will disturb that. BjÃrn -- To unsubscribe from this list: send the line "unsubscribe linux-net" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
