[Dnsmasq-discuss] Unable to configure stateful prefix length larger than 64

[Pablo Rodríguez Fernández]

This seems related to this thread:
http://lists.thekelleys.org.uk/pipermail/dnsmasq-discuss/2013q1/006817.html

El 26/02/13 18:05, Pablo Rodríguez Fernández escribió:
> Hi,
>
> I've installed dnsmasq v2.62 and have tried to do the same that is
> described on
> http://lists.thekelleys.org.uk/pipermail/dnsmasq-discuss/2012q2/005878.html,
> being unable to setup a client host with the correct prefix length,
> getting always an /64 address.
>
> This is my (dhcpv6 relevant) dnsmasq.conf:
>     domain-needed
>     dhcp-range=fc00::14, fc00::1f, 124, 5m
>     dhcp-option=option6:dns-server,fc00::11
>     enable-ra
>     log-dhcp
>
> I checked with tcpdump that router sends router advertisements with the
> correct prefix-length (unsoliciting or soliciting them with rdisc6):
>     16:54:59.200913 IP6 (hlim 255, next-header ICMPv6 (58) payload
> length: 8) fe80::219:66ff:fe38:6cf4 > ff02::2: [icmp6 sum ok] ICMP6,
> router solicitation, length 8
>     16:54:59.202489 IP6 (class 0xc0, hlim 255, next-header ICMPv6 (58)
> payload length: 88) fe80::ba27:ebff:fe93:eafb >
> fe80::219:66ff:fe38:6cf4: [icmp6 sum ok] ICMP6, router advertisement,
> length 88
>         hop limit 64, Flags [managed, other stateful], pref medium,
> router lifetime 1800s, reachable time 0s, retrans time 0s
>           prefix info option (3), length 32 (4): fc00::10/124, Flags
> [none], valid time 7200s, pref. time 7200s
>           mtu option (5), length 8 (1):  1500
>           source link-address option (1), length 8 (1): b8:27:eb:93:ea:fb
>           rdnss option (25), length 24 (3):  lifetime 1800s, addr: fc00::11
>
> server is routing:
>     $ sysctl -a | grep forwarding | grep ipv6 | grep -v \.lo
>     net.ipv6.conf.all.forwarding = 1
>     net.ipv6.conf.default.forwarding = 1
>     net.ipv6.conf.eth0.forwarding = 1
>
> and client is configured to accept ra:
>     $ sysctl -a | grep accept_ra | grep -v \.lo
>     net.ipv6.conf.all.accept_ra = 1
>     net.ipv6.conf.all.accept_ra_defrtr = 1
>     net.ipv6.conf.all.accept_ra_pinfo = 1
>     net.ipv6.conf.all.accept_ra_rtr_pref = 1
>     net.ipv6.conf.all.accept_ra_rt_info_max_plen = 0
>     net.ipv6.conf.default.accept_ra = 1
>     net.ipv6.conf.default.accept_ra_defrtr = 1
>     net.ipv6.conf.default.accept_ra_pinfo = 1
>     net.ipv6.conf.default.accept_ra_rtr_pref = 1
>     net.ipv6.conf.default.accept_ra_rt_info_max_plen = 0
>     net.ipv6.conf.eth0.accept_ra = 1
>     net.ipv6.conf.eth0.accept_ra_defrtr = 1
>     net.ipv6.conf.eth0.accept_ra_pinfo = 1
>     net.ipv6.conf.eth0.accept_ra_rtr_pref = 1
>     net.ipv6.conf.eth0.accept_ra_rt_info_max_plen = 0
>
> But, when i do
>     $ sudo dhclient -6 -1 -v eth0
>
> i get:
>     inet6 addr: fc00::18/64 Scope:Global
>
> instead of:
>     inet6 addr: fc00::18/124 Scope:Global
>
> I also tried setting net.ipv6.conf.all.autoconf = 0 and others dhcp
> client like dibbler-client or dhcp6c (from wide/kame) without success.
> I've noticed that any of dhcp client i tried sends router solicitations,
> could it be the problem?
>
> Seems that other people
> (https://forums.gentoo.org/viewtopic-t-833454-start-0.html) has
> successfully assigned prefix length larger than 64 using dhcp+some ra
> software (dnsmasq/radvd).
>
> Am i missing something? May it be related to the multiple of 8 prefix
> length bug
> (http://lists.thekelleys.org.uk/pipermail/dnsmasq-discuss/2012q2/005879.html)
> ?
>
> Sorry if this shouldn't be answered here, but i don't know where or to
> who i should address this question.
>
> Greetings,
> Pablo