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Joined: Sat Mar 05, 2016 1:17 pm

flipping of IPv6 prefixes on interfaces between restarts

Thu Apr 07, 2016 4:24 pm


question about behavior of IPv6 assignment to interfaces from an pool.

I got a /56 from my provider via DHCPD-PD, assign from the pool on /64 to LAN1 the next to LAN5.

From upstream in pool

now on the first start, i got

2003:xxxx:xxxx:xx00/64 on LAN1 (set in the Adress list 2003:xxxx:xxxx:xx00::1/64)
2003:xxxx:xxxx:xx01/64 on LAN5 (set in the Adress list 2003:xxxx:xxxx:xx01::1/64)

which is what i want so far, only the 00::/64 prefix is with advertisement and autoconfiguration.
The 01::/64 is for static configuration(server)

After an reboot of the router the addresses flips.

2003:xxxx:xxxx:xx01::1/64 on LAN1
2003:xxxx:xxxx:xx00::1/64 on LAN5

And with this, different settings are now wrong which i set on the interface, so i must change.

Router is an CCR1009 with v6.35rc42

Known behavior, or bug?
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Re: flipping of IPv6 prefixes on interfaces between restarts

Thu Apr 07, 2016 4:56 pm

I have seen this too. Rather inconvenient, at the least! I know it also happens in 6.34. And seem to recall it happening in prior releases, but can't be certain.

However, I have only seen this behavior after adding/deleting an IPv6 interface and rebooting. Then it may reassign the prefixes.

As in other platforms I have used, MT should allow you to specify the IPv6 addresses via the prefix sequence in the pool. Example, prefix 0, 1, 2, etc. This works well and does not rely on the an interface index number (or whatever it is currently using to assign a prefix from the DHCP-PD pool).

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