dhcpcd-discuss

Hello Roy

On January 6, 2018 at 4:54:20 am +01:00, dhcpcd-discuss@xxxxxxxxxxxx wrote:

Hi Jan

On 05/01/2018 20:30, Jan Herrygers wrote:

Hello

I'm testing/using dhcpcd 7.0.0 on Slackware64-current, mainly related to IPv6. I have seen 2 areas that may have some room for improvement:

- IPv6 autoconfiguration through the kernel is disabled by dhcpcd when it is started with the -4 flag. Also, when dhcpcd is started with the -6 flag, IPv4 configuration is altered. I have attached a diff of the sysctl before and after I run dhcpcd -4 wlan0. The diff is the same if I run dhcpcd -6 wlan0.

--> I'd expect configuration to be left alone for the protocol (IPv4/IPv6) that isnot used by dhcpcd.

- if dhcpcd is started with the -6 flag, it keeps running in the foreground after configuring the IPv6 address till it times out and exits. It doesn't fork to the background. I have a tcpdump of the router advertisement that I receive.

--> I'd expect dhcpcd to fork to the background after configuring the IPv6 addresses, so it can handle additional router advertisements

What is your opinion about these?

There argument provided here for the current status quo is quite compelling.

See the recent thread here:

https://roy.marples.name/archives/dhcpcd-discuss/0001880.html

Roy

Thank you for your kind answer.

I get the argument provided in the archive for disabling IPv6 in the kernel.

When does dhcpcd disable the kernel IPv6 autoconf and address generation? If it is only when dhcpcd is started, then I guess it is just as easy for me to re-enable the kernel IPv6 after starting dhcpcd if I want it.

For the other thing I mentioned:

- if dhcpcd is started with the -6 flag, it keeps running in the foreground after configuring the IPv6 address till it times out and exits. It doesn't fork to the background. I have a tcpdump of the router advertisement that I receive.

--> I'd expect dhcpcd to fork to the background after configuring the IPv6 addresses, so it can handle additional router advertisements

I don't see how the archive post supports dhcpcd exiting rather than forking to the background when it is started with the -6 flag. Can you enlighten me on that one?

Jan