nixos/tests: use ::1 instead of anycast address (#96250)

According to RFC4291[1], 2001:db8:: is the anycast address for the
prefix and will be answered by all routers responsible for this prefix.
This means that before the iputils bump, the ping from client to isp was
answered by the router and not by the ISP machine. Switching away from
the anycast address fixes this issue.

Credits for finding this go to @primeos.

[1]: https://tools.ietf.org/html/rfc4291#section-2.6.1

Fixes #96188

1 files changed, 4 insertions, 4 deletions

diff --git a/nixos/tests/systemd-networkd-ipv6-prefix-delegation.nix b/nixos/tests/systemd-networkd-ipv6-prefix-delegation.nix
index 99cd341eec15e..99395fe3023f3 100644
--- a/nixos/tests/systemd-networkd-ipv6-prefix-delegation.nix
+++ b/nixos/tests/systemd-networkd-ipv6-prefix-delegation.nix
@@ -31,7 +31,7 @@ import ./make-test-python.nix ({pkgs, ...}: {
         firewall.enable = false;
         interfaces.eth1.ipv4.addresses = lib.mkForce []; # no need for legacy IP
         interfaces.eth1.ipv6.addresses = lib.mkForce [
-          { address = "2001:DB8::"; prefixLength = 64; }
+          { address = "2001:DB8::1"; prefixLength = 64; }
         ];
       };
 
@@ -260,7 +260,7 @@ import ./make-test-python.nix ({pkgs, ...}: {
     client.wait_until_succeeds("ping -6 -c 1 FD42::1")
 
     # the global IP of the ISP router should still not be a reachable
-    router.fail("ping -6 -c 1 2001:DB8::")
+    router.fail("ping -6 -c 1 2001:DB8::1")
 
     # Once we have internal connectivity boot up the ISP
     isp.start()
@@ -273,11 +273,11 @@ import ./make-test-python.nix ({pkgs, ...}: {
 
     # wait until the uplink interface has a good status
     router.wait_for_unit("network-online.target")
-    router.wait_until_succeeds("ping -6 -c1 2001:DB8::")
+    router.wait_until_succeeds("ping -6 -c1 2001:DB8::1")
 
     # shortly after that the client should have received it's global IPv6
     # address and thus be able to ping the ISP
-    client.wait_until_succeeds("ping -6 -c1 2001:DB8::")
+    client.wait_until_succeeds("ping -6 -c1 2001:DB8::1")
 
     # verify that we got a globally scoped address in eth1 from the
     # documentation prefix