Net.ipv6.conf.default.disable_ipv6

Rocky Linux Tech Help
1

Hello

Please tell me about “net.ipv6.conf.default.disable_ipv6”.

  1. If you set it to 1 with sysctl, in what specific cases can you see the effect?

Since it’s the default, I thought that adding a new NIC would change whether the NIC has a v6 address or not, but that wasn’t the case.

  1. When using sysctl to disable ipv6, I’ve seen examples of setting the following two things.

net.ipv6.conf.all.disable_ipv6 = 1

net.ipv6.conf.default.disable_ipv6 = 1

However, if you set all to 1, I think default will also be set to 1, but do you know why most people set both to 1?

Thank you in advance.

2

I do include ipv6.method disabled when I create a new connection (or modify existing) with nmcli. The interface does still get link-local IPv6 address, but nothing more.

3

Thank you.

I also set ipv6.method to “disable” when I’m not using ipv6.

However, I was wondering in what cases the following parameter settings are meaningful, so I asked:

net.ipv6.conf.default.disable_ipv6

4

https://www.kernel.org/doc/Documentation/networking/ip-sysctl.txt said that disable_ipv6 is a boolean.

linux - What is the difference between "all", "default" and "eth*" in /proc/sys/net/ipv[46]/conf/? - Unix & Linux Stack Exchange said that the ‘default’ affects only interfaces that are added (later),
and that the ‘all’ modifies the existing interfaces.

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