@@ -564,6 +564,41 @@ func (s *DockerDaemonSuite) TestDaemonBridgeIP(c *check.C) {

 	deleteInterface(c, defaultNetworkBridge)

 }

+func (s *DockerDaemonSuite) TestDaemonRestartWithBridgeIPChange(c *check.C) {

+	if err := s.d.Start(); err != nil {

+		c.Fatalf("Could not start daemon: %v", err)

+	}

+	defer s.d.Restart()

+	if err := s.d.Stop(); err != nil {

+		c.Fatalf("Could not stop daemon: %v", err)

+	}

+

+	// now we will change the docker0's IP and then try starting the daemon

+	bridgeIP := "192.169.100.1/24"

+	_, bridgeIPNet, _ := net.ParseCIDR(bridgeIP)

+

+	ipCmd := exec.Command("ifconfig", "docker0", bridgeIP)

+	stdout, stderr, _, err := runCommandWithStdoutStderr(ipCmd)

+	if err != nil {

+		c.Fatalf("failed to change docker0's IP association: %v, stdout: %q, stderr: %q", err, stdout, stderr)

+	}

+

+	if err := s.d.Start("--bip", bridgeIP); err != nil {

+		c.Fatalf("Could not start daemon: %v", err)

+	}

+

+	//check if the iptables contains new bridgeIP MASQUERADE rule

+	ipTablesSearchString := bridgeIPNet.String()

+	ipTablesCmd := exec.Command("iptables", "-t", "nat", "-nvL")

+	out, _, err := runCommandWithOutput(ipTablesCmd)

+	if err != nil {

+		c.Fatalf("Could not run iptables -nvL: %s, %v", out, err)

+	}

+	if !strings.Contains(out, ipTablesSearchString) {

+		c.Fatalf("iptables output should have contained new MASQUERADE rule with IP %q, but was %q", ipTablesSearchString, out)

+	}

+}

+

 func (s *DockerDaemonSuite) TestDaemonBridgeFixedCidr(c *check.C) {

 	d := s.d

@@ -5,7 +5,6 @@ import (

 	"fmt"

 	"net"

 	"os/exec"

-	"regexp"

 	"strconv"

 	"strings"

 	"sync"

@@ -267,14 +266,7 @@ func Exists(table Table, chain string, rule ...string) bool {

 	ruleString := strings.Join(rule, " ")

 	existingRules, _ := exec.Command(iptablesPath, "-t", string(table), "-S", chain).Output()

-	// regex to replace ips in rule

-	// because MASQUERADE rule will not be exactly what was passed

-	re := regexp.MustCompile(`[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}\/[0-9]{1,2}`)

-

-	return strings.Contains(

-		re.ReplaceAllString(string(existingRules), "?"),

-		re.ReplaceAllString(ruleString, "?"),

-	)

+	return strings.Contains(string(existingRules), ruleString)

 }

 // Call 'iptables' system command, passing supplied arguments