Receiving a /56 DHCPv6 prefix delegation
CharlesLaCour
Newbie ✭
I have a TZ-670 currently running SonicOS 7.0.1-5018. With the 6.x version of SonicOS you were able to set a preferred prefix delegation with a prefix length. My ISP provides both a /64 and /56 prefix but without this hint with the prefix length in the preferred prefix delegation I only get the /64.
Since it is best practice to not subdivide a IPv6 /64 and I have IPv6 on multiple interfaces in different zones I would really like to get back to getting the /56 prefix.
Also along the same lines when I was able to get a /56 prefix delegation there was no easy way to assign addresses from this on more than one interface without having to include the entire /64 subnet address from the /56 delegation.
Category: Entry Level Firewalls
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Answers
I have the same question. Were you able to find a solution anywhere?
No, I have not.
I thought I was going crazy until I found this thread.
I have a TZ-670 with SonicOS 7.1.1-7058. I am also only getting a delegation of length /64 from my ISP, and cannot find a way to request a different length like /56 or /60.
I am trying to turn on IPv6 on a Guest WLAN that has been configured as a VLAN.
Appears to have finally been resolved in SonicOS 7.1.3-7015-R6965, which was released in January 2025.
Yes, I opened up a support ticket and spent months goin back and forth with support until they finally got development to add the prefix length to the DHCPv6 page in a hot fix they had me try and it worked.
There was still an issue with the router advertising and stateless addressing for the clients unless there was a static IPv6 address on the interface which defeats the purpose of a delegated prefix.
I am actually running OPNSense at home now and disconnected my TZ-670.