return err
		}

		err := startDNS.Execute(context)
		Expect(err).NotTo(HaveOccurred())

		Expect(ns.ExecuteCallCount()).To(Equal(1))

		Expect(linkFactory.CreateDummyCallCount()).To(Equal(1))
		linkName := linkFactory.CreateDummyArgsForCall(0)
		Expect(linkName).To(Equal("dns0"))
	})

	It("sets the address on the dummy device in the sandbox namespace", func() {
		ns.ExecuteStub = func(callback func(*os.File) error) error {
			Expect(addressManager.AddAddressCallCount()).To(Equal(0))
			err := callback(nil)
			Expect(addressManager.AddAddressCallCount()).To(Equal(1))
			return err
		}

		err := startDNS.Execute(context)
		Expect(err).NotTo(HaveOccurred())

		Expect(addressManager.AddAddressCallCount()).To(Equal(1))
		ifName, address := addressManager.AddAddressArgsForCall(0)
		Expect(ifName).To(Equal("dns0"))
		Expect(address.IP.String()).To(Equal("10.10.10.10"))
	})

	It("ups the dummy device in the sandbox namespace", func() {