Arch Linux

Basic-Master

Member

Registered: 2007-10-30

Posts: 21

dhcpcd prevents assignment of IPv6 addresses

I use netctl to manage my network interfaces and some while ago I noticed that my interfaces no longer get any IPv6 addresses. At first I thought this would be a temporary bug but today I found out that dhcpcd actually sets net.ipv6.conf.*.accept_ra to 0, which prevents SLAAC/DHCPv6 via dhclient+netctl. Can anyone confirm this? Once I changed netctl to use dhclient instead of dhcpcd, this problem disappeared and my adapters get both IPv4 and IPv6 addresses again.

Trilby

Inspector Parrot

Registered: 2011-11-29

Posts: 29,523

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Re: dhcpcd prevents assignment of IPv6 addresses

I use netctl ... I noticed that my interfaces no longer get any IPv6 addresses.

Do you have this configured?

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"UNIX is simple and coherent..." - Dennis Ritchie, "GNU's Not UNIX" -  Richard Stallman

Basic-Master

Member

Registered: 2007-10-30

Posts: 21

Re: dhcpcd prevents assignment of IPv6 addresses

Well I tried that as well but it didn't change the fact that the dhcpcd changed accept_ra to 0, which then prevents SLAAC AFAICT.

V1del

Forum Moderator

Registered: 2012-10-16

Posts: 21,672

Re: dhcpcd prevents assignment of IPv6 addresses

Yes dhcpcd explicitly does/did this: https://bbs.archlinux.org/viewtopic.php … 6#p1772486

Basic-Master

Member

Registered: 2007-10-30

Posts: 21

Re: dhcpcd prevents assignment of IPv6 addresses

I see - thanks for the link.

In this case I'd claim there is something wrong with netctl - if dhcpcd must be used for the assignment of IPv6 addresses, wouldn't it be right to use dhcpcd for IPv6 as well instead of dhclient if IP6=dhcp is configured in a profile?
At least with the current default netctl config no dynamic IPv6 addresses can be obtained due to the fact that dhcpcd modifies accept_ra and that netctl invokes dhclient if IP6 is set to dhcp.