bgp: Unnumbered, disable v4, enable v6.

The end goal is to have full BGP unnumbered support including routing of IPv4 prefixes over IPv6 nexthop, but the support is not yet there. Signed-off-by: Frode Nordahl <[email protected]> Signed-off-by: Martin Kalcok <[email protected]>
canonical · Nov 1, 2024 · 6af41c1 · 6af41c1
1 parent 984372b
commit 6af41c1
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diff --git a/microovn/frr/bgp/redirect.go b/microovn/frr/bgp/redirect.go
@@ -356,18 +356,67 @@ func startBgpUnnumbered(_ context.Context, extConnections []types.BgpExternalCon
 
 	var confBuilder strings.Builder
 	fmt.Fprintln(&confBuilder, "configure")
+
+	// Ensure we don't announce any default route from VRF to our peer.
+	fmt.Fprint(&confBuilder, `
+ip prefix-list no-default seq 5 deny 0.0.0.0/0
+ip prefix-list no-default seq 10 permit 0.0.0.0/0 le 32
+ipv6 prefix-list no-default seq 5 deny ::/0
+ipv6 prefix-list no-default seq 10 permit ::/0 le 128
+`)
+
 	fmt.Fprintf(&confBuilder, "router bgp %s vrf %s\n", asn, vrfName)
 	for _, connection := range extConnections {
 		fmt.Fprintf(&confBuilder,
 			"neighbor %s interface remote-as external\n",
 			getBgpRedirectIfaceName(connection.Iface),
 		)
+
+		// Disable IPv4 address family until we actually have support for
+		// routing IPv4 prefixes over IPv6 nexthops in OVN.
+		fmt.Fprint(&confBuilder,
+			"address-family ipv4 unicast\n",
+		)
+		fmt.Fprintf(&confBuilder,
+			"no neighbor %s activate\n",
+			getBgpRedirectIfaceName(connection.Iface),
+		)
+		fmt.Fprintln(&confBuilder,
+			"exit-address-family",
+		)
+
+		// Enable IPv6 address family.
+		fmt.Fprint(&confBuilder,
+			"address-family ipv6 unicast\n",
+		)
+		fmt.Fprintf(&confBuilder,
+			"neighbor %s soft-reconfiguration inbound\n",
+			getBgpRedirectIfaceName(connection.Iface),
+		)
+		fmt.Fprintf(&confBuilder,
+			"neighbor %s prefix-list no-default out\n",
+			getBgpRedirectIfaceName(connection.Iface),
+		)
+		fmt.Fprintln(&confBuilder,
+			"redistribute kernel",
+		)
+		fmt.Fprintf(&confBuilder,
+			"neighbor %s activate\n",
+			getBgpRedirectIfaceName(connection.Iface),
+		)
+		fmt.Fprintln(&confBuilder,
+			"exit-address-family",
+		)
 	}
 	fmt.Fprintln(&confBuilder, "do copy running-config startup-config")
 
 	cmd := exec.Command(filepath.Join(paths.Wrappers(), "vtysh"))
 	cmd.Stdin = strings.NewReader(confBuilder.String())
-	err := cmd.Run()
+	err := cmd.Start()
+	if err != nil {
+		return err
+	}
+	err = cmd.Wait()
 	return err
 }
 

diff --git a/tests/test_helper/bgp_utils.bash b/tests/test_helper/bgp_utils.bash
@@ -28,8 +28,19 @@ function frr_start_bgp_unnumbered() {
 
     cat << EOF | lxc_exec "$container" "vtysh"
         configure
+        !
         router bgp $asn
         neighbor $interface interface remote-as external
+        !
+        address-family ipv4 unicast
+          no neighbor $interface activate
+        exit-address-family
+        !
+        address-family ipv6 unicast
+          neighbor $interface soft-reconfiguration inbound
+          neighbor $interface activate
+        exit-address-family
+        !
 EOF
 }
 
@@ -46,8 +57,19 @@ function microovn_start_bgp_unnumbered() {
 
     cat << EOF | lxc_exec "$container" "microovn.vtysh"
         configure
+        !
         router bgp $asn vrf $vrf
         neighbor $interface interface remote-as external
+        !
+        address-family ipv4 unicast
+          no neighbor $interface activate
+        exit-address-family
+        !
+        address-family ipv6 unicast
+          neighbor $interface soft-reconfiguration inbound
+          neighbor $interface activate
+        exit-address-family
+        !
 EOF
 }