Using bridges under NixOS: Difference between revisions

Latest revision as of 22:21, 27 October 2024

This article has been nominated for deletion.

Reason: The related bug has been fixed and the contents of this page no longer apply to a modern NixOS, which uses systemd-networkd. (Discuss in Talk:Using bridges under NixOS#)
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In order to use macvtap bridges in KVM, LXC, Xen or another hypervisor on NixOS, you have to configure your DHCP server to not assign an IP address to that interface.

By default, the DHCP server on NixOS configures every interface with an IP.

Configuration

If you are running dhcpcd, then you have to define a denyInterfaces parameter:

configuration.nix

{
  networking.dhcpcd.denyInterfaces = [ "macvtap0@*" ];
}

Tip

In order to affect your NixOS system by your nix-language-specific changes you must first evaluate it:

$ nixos-rebuild switch --use-remote-sudo

Issue #67966 is relevant for DHCP and bridging.

@@ Line 1: / Line 1: @@
-==Using bridges under NixOS ==
+{{Delete|The related bug has been fixed and the contents of this page no longer apply to a modern NixOS, which uses systemd-networkd.}}
+In order to use macvtap bridges in KVM, LXC, Xen or another hypervisor on NixOS, you have to configure your DHCP server to not assign an IP address to that interface.
-If you want to use macvtap bridges in KVM, LXC, Xen or $hypervisor on NixOS you have to tell your
+By default, the DHCP server on NixOS configures every interface with an IP.
-dhcp server to not configure that interface with an ip.
-Yes exactly the dhcp server on NixOS configures every interface as long it has been told to not to.
-If you are running dhcpcd then you have to define
+== Configuration ==
- networking.dhcpcd.denyInterfaces = [ "macvtap0@*" ]
-for example.
-What is the error you get when layer 2 bridges have IPs?
+If you are running <code>dhcpcd</code>, then you have to define a <code>denyInterfaces</code> parameter:
-[https://serverfault.com/questions/959667/kvm-bridge-networking-first-arp-packet-gets-answered-by-wrong-host stackoverflow issue]
+{{file|configuration.nix|nix|
+<nowiki>
+{
+  networking.dhcpcd.denyInterfaces = [ "macvtap0@*" ];
+}
+</nowiki>
+}}
+{{Evaluate}}
-Open bug: https://github.com/NixOS/nixpkgs/issues/67966
+Issue {{issue|67966}} is relevant for DHCP and bridging.
 [[Category:Virtualization]]