Re: dhcpcd and routing of ipv6 prefixes

[Roy Marples <roy%marples.name@localhost>]

Hi

On 08/06/2016 23:07, Rhialto wrote:
> (oops, should have sent this to tech-net@ ...)
> 
> Can it be that if I use dhcpcd to obtain an IPv6 prefix from my router
> (a FritzBox in my case), and it assigns the prefix::1 address to the
> desired interface, that still no routing in that direction occurs?
> 
> Here is my case:
> 
> dhcpcd.conf:
> 
>     interface re0
> 	noipv4
> 
>     interface re1
> 	# enable routing solicitation get the default IPv6 route
> 	ipv6rs
> 	# also the default IPv4 route will go here
> 	gateway
> 	# request an IPv6 address
> 	ia_na 1
> 	# get a /64 and assign it to re0
> 	ia_pd 2 re0/0
> 
> ifconfig re0:
> 
> re0: ...
>         inet 10.0.0.16 netmask 0xffffff00 broadcast 10.0.0.255
>         inet6 fe80::d63d:7eff:fe2d:6798%re0 prefixlen 64 scopeid 0x1
>         inet6 2001:984:4b2a:fc::1 prefixlen 64
> 
> # The route to internal addresses goes to the default (i.e. wrong) interface,
> # not to re0 as it should:
> 
> $ route get -inet6 2001:984:4b2a:fc:226:9eff:fece:8c54
>    route to: vargaz.falu.nl
> destination: ::
>        mask: default
>     gateway: fe80::ca0e:14ff:feee:a54b%re1
>  local addr: fe80::5008:f7e9:73dd:7e21%re1
>   interface: re1
>       flags: <UP,GATEWAY,DONE,STATIC>
>  recvpipe  sendpipe  ssthresh  rtt,msec    rttvar  hopcount      mtu     expire
>        0         0         0         0         0         0      1492         0 
> 
> $ netstat -rn -f inet6 | grep re0
> fe80::%re0/64                      link#1                         UC          -        -      -  re0
> fe80::222:15ff:fe60:7f54           00:22:15:60:7f:54              UHLc        -        -      -  re0
> fe80::226:9eff:fece:8c54           00:26:9e:ce:8c:54              UHLc        -        -      -  re0
> ff01:1::/32                        link#1                         UC          -        -      -  re0
> ff02::%re0/32                      link#1                         UC          -        -      -  re0
> 
> $ ndp -a | grep re0
> Neighbor                             Linklayer Address  Netif Expire    S Flags
> murthe.falu.nl                       d4:3d:7e:2d:67:98    re0 permanent R 
> fe80::222:15ff:fe60:7f54%re0         00:22:15:60:7f:54    re0 23h33m53s S 
> fe80::226:9eff:fece:8c54%re0         00:26:9e:ce:8c:54    re0 23h48m9s  S 
> fe80::d63d:7eff:fe2d:6798%re0        d4:3d:7e:2d:67:98    re0 permanent R 

So it looks like the route to 2001:984:4b2a:fc is on the wrong
interfacce. You've not shown the whole routing table, but is it by any
chance on lo0 as a reject route?

I've made some fixes for PD upstream and show hopefully be releasing a
new version next week. Can you test a snapshot for me please to see if
it fixes it?

http://roy.marples.name/projects/dhcpcd/tarball/dhcpcd-trunk.tar.gz
(login as anonymous first)

Roy