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pool6 refused acquire: bad preferred prefix! (6)
Posted: Sun Feb 05, 2017 1:44 pm
by crodler
Hello,
Routeros 6.38.1 PPPOE Server with DHCPv6 PD enabled.
IPv6 pool: Prefix xxxx:yyyy::/52 Prefix length: 64
Client: Ubnt Airos6: DHCPv6 client on pppoe, Prefix Delegation with statefull DHCPv6 Server, IPv6 Prefix Length: 64 on lan.
Everything works correctly with IPv6, but on PPPOE Server i get the above error: pool6 refused acquire: bad preferred prefix! (6)
What's wrong?
Re: pool6 refused acquire: bad preferred prefix! (6)
Posted: Fri Feb 17, 2017 2:31 pm
by oscarc
I've got similar error:
pool6 refused acquire: pool not found:
And I have the pool defined in both, server and client?
Any idea?
Thanks in advance
Re: pool6 refused acquire: bad preferred prefix! (6)
Posted: Mon Feb 27, 2017 11:03 am
by SDFadfasdfadsf
same issue, DHCPv6 server is broken
I have a /56 from DHCPv6 client. Trying to hand out this /56 with DHCPv6 server, keeps getting this error in log
Re: pool6 refused acquire: bad preferred prefix! (6)
Posted: Thu Aug 10, 2017 6:03 pm
by locodog
Problem is not in Mikrotik dhcpv6 server, when you set prefix length in ubnt lan interface to /64 it requests from Mikrotik /64 and that is != /60 configured in Pool, that's why error happens.
If you configure ubnt lan to request /60 and set stateless dhcp, there is no error in log, prefix is accepted and /64 is assigned to lan interface of ubnt.
Re: pool6 refused acquire: bad preferred prefix! (6)
Posted: Thu Aug 10, 2017 6:43 pm
by ZeroByte
OP specified that the prefix-length in the pool is /64, not /60, so that may not be the problem for him.
Re: pool6 refused acquire: bad preferred prefix! (6)
Posted: Sat Aug 12, 2017 12:55 pm
by locodog
I reject your reality and substitute my own!
Re: pool6 refused acquire: bad preferred prefix! (6)
Posted: Thu Oct 18, 2018 11:33 am
by crodler
After update to 6.43.4 the ubiquiti client doesn't get prefix anymore and router throws above error continuously.
Re: pool6 refused acquire: bad preferred prefix! (6)
Posted: Tue Oct 23, 2018 7:51 pm
by simeitg
Same problema here with CPE Intelbrás WOM 5000 MIMO. CPE is set to AUTO but get /64 instead of /56.
Re: pool6 refused acquire: bad preferred prefix! (6)
Posted: Tue Oct 23, 2018 8:02 pm
by simeitg
Re: pool6 refused acquire: bad preferred prefix! (6)
Posted: Tue Nov 06, 2018 7:45 pm
by simeitg
After update to 6.43.4 the ubiquiti client doesn't get prefix anymore and router throws above error continuously.
same here
Re: pool6 refused acquire: bad preferred prefix! (6)
Posted: Mon Nov 19, 2018 5:32 am
by bearmeister
Found this post after searching for same symptoms - Did anyone find a resolution?
Thank you
Re: pool6 refused acquire: bad preferred prefix! (6)
Posted: Mon Nov 26, 2018 10:31 pm
by simeitg
Found this post after searching for same symptoms - Did anyone find a resolution?
Thank you
Nothing yet!
Re: pool6 refused acquire: bad preferred prefix! (6)
Posted: Fri Nov 30, 2018 9:29 am
by GZ15
For anyone wondering, we tried to downgrade the RouterOS on hEX Lite with this problem (we were running 6.43.4). The router itself didn't downgrade (consumed the ROS package - ?) but the DHCPv6 client started working. So it might be worth a shot for you till this is fixed.
Re: pool6 refused acquire: bad preferred prefix! (6)
Posted: Mon Jun 17, 2019 11:23 am
by frogale
Any news on that?
Re: pool6 refused acquire: bad preferred prefix! (6)
Posted: Thu Feb 25, 2021 7:54 am
by seriousblack
Any update on this?
Re: pool6 refused acquire: bad preferred prefix! (6)
Posted: Tue Jan 23, 2024 8:15 am
by Archous
Just wanted to let folks know we kept banging our head on this problem. Turns out if you put "0" in for the IPv6 prefix length of the airMax settings then it just honors what the Mikrotik DHCPv6 server/pool offers.
