[Dnsmasq-discuss] 128 bit prefix length on static ipv6 lease

[Roger James]

My static ipv6 leases get delivered with a 128 bit prefix length.

eth0: flags=4163<UP,BROADCAST,RUNNING,MULTICAST> mtu 1500
inet 192.168.10.9 netmask 255.255.255.0 broadcast 192.168.10.255
inet6 fe80::681:fbbe:cf42:4bf prefixlen 64 scopeid 0x20<link>
inet6 fda0:4d7f:afbb::9 prefixlen 128 scopeid 0x0<global>
inet6 2001:8b0:1418:4c2f2::9 prefixlen 64 scopeid 0x0<global>


The prefix on the 2001:8b0:1418:4c2f address is 64 because I have overidden
it with a locally defined static address. The prefix on the fda0:4d7f:afbb
address is as delivered by dnsmasq. I cannot see an obvious way to override
this in the routers dnsmasq config. The hostid is correct so it would
appear that my DUID is also correct. What am I missing?

Roger

[Pali Rohár]

Post by Roger James
My static ipv6 leases get delivered with a 128 bit prefix length.
eth0: flags=4163<UP,BROADCAST,RUNNING,MULTICAST> mtu 1500
inet 192.168.10.9 netmask 255.255.255.0 broadcast 192.168.10.255
inet6 fe80::681:fbbe:cf42:4bf prefixlen 64 scopeid 0x20<link>
inet6 fda0:4d7f:afbb::9 prefixlen 128 scopeid 0x0<global>
inet6 2001:8b0:1418:4c2f2::9 prefixlen 64 scopeid 0x0<global>
The prefix on the 2001:8b0:1418:4c2f address is 64 because I have overidden
it with a locally defined static address. The prefix on the fda0:4d7f:afbb
address is as delivered by dnsmasq. I cannot see an obvious way to override
this in the routers dnsmasq config. The hostid is correct so it would appear
that my DUID is also correct. What am I missing?

Hi! DHCPv6 assign just one IPv6 address which means address with /128
prefix. Routing in IPv6 is done via Router Advertisement (which dnsmasq
supports too). What is the output of route -n? Is there route for that
your fda0:4d7f:afbb:: prefix?