fib: Don't use an address from an attached prefix when sending ARP requests.

Change-Id: I4c3144794dd0bd7de6150929e53f6d305c496b17

Type: fix
Signed-off-by: Neale Ranns <neale@graphiant.com>
Change-Id: I7b0c2c2dec5e867970599b8f2f2da17f2ff0b17c

1 files changed, 22 insertions, 0 deletions

diff --git a/test/test_neighbor.py b/test/test_neighbor.py
index b600a97c3c2..24737da0eca 100644
--- a/test/test_neighbor.py
+++ b/test/test_neighbor.py
@@ -2069,6 +2069,28 @@ class ARPTestCase(VppTestCase):
         for rx in rxs:
             self.verify_arp_req(rx, self.pg1.local_mac, "10.0.1.2", "10.0.1.128")
 
+        # apply an attached prefix to the interface
+        # since there's no local address in this prefix,
+        # any other address is used
+        p3 = (
+            Ether(src=self.pg0.remote_mac, dst=self.pg0.local_mac)
+            / IP(src=self.pg1.remote_ip4, dst="10.0.2.128")
+            / Raw(b"0x5" * 100)
+        )
+
+        VppIpRoute(
+            self,
+            "10.0.2.0",
+            24,
+            [VppRoutePath("0.0.0.0", self.pg1.sw_if_index)],
+        ).add_vpp_config()
+
+        rxs = self.send_and_expect(self.pg0, [p3], self.pg1)
+        for rx in rxs:
+            self.verify_arp_req(
+                rx, self.pg1.local_mac, self.pg1.local_ip4, "10.0.2.128"
+            )
+
         # cleanup
         conn3.remove_vpp_config()
         conn2.remove_vpp_config()