diff --git a/caddyhttp/httpserver/context.go b/caddyhttp/httpserver/context.go
index 196337d9..050e1830 100644
--- a/caddyhttp/httpserver/context.go
+++ b/caddyhttp/httpserver/context.go
@@ -134,7 +134,7 @@ func (c Context) Port() (string, error) {
 	if err != nil {
 		if !strings.Contains(c.Req.Host, ":") {
 			// common with sites served on the default port 80
-			return "80", nil
+			return HTTPPort, nil
 		}
 		return "", err
 	}
diff --git a/caddyhttp/httpserver/https.go b/caddyhttp/httpserver/https.go
index 60b0c242..fcbd2d90 100644
--- a/caddyhttp/httpserver/https.go
+++ b/caddyhttp/httpserver/https.go
@@ -93,7 +93,7 @@ func enableAutoHTTPS(configs []*SiteConfig, loadCertificates bool) error {
 			cfg.TLS.Enabled &&
 			(!cfg.TLS.Manual || cfg.TLS.OnDemand) &&
 			cfg.Addr.Host != "localhost" {
-			cfg.Addr.Port = "443"
+			cfg.Addr.Port = HTTPSPort
 		}
 	}
 	return nil
@@ -108,8 +108,8 @@ func enableAutoHTTPS(configs []*SiteConfig, loadCertificates bool) error {
 func makePlaintextRedirects(allConfigs []*SiteConfig) []*SiteConfig {
 	for i, cfg := range allConfigs {
 		if cfg.TLS.Managed &&
-			!hostHasOtherPort(allConfigs, i, "80") &&
-			(cfg.Addr.Port == "443" || !hostHasOtherPort(allConfigs, i, "443")) {
+			!hostHasOtherPort(allConfigs, i, HTTPPort) &&
+			(cfg.Addr.Port == HTTPSPort || !hostHasOtherPort(allConfigs, i, HTTPSPort)) {
 			allConfigs = append(allConfigs, redirPlaintextHost(cfg))
 		}
 	}
@@ -135,18 +135,19 @@ func hostHasOtherPort(allConfigs []*SiteConfig, thisConfigIdx int, otherPort str
 // redirPlaintextHost returns a new plaintext HTTP configuration for
 // a virtualHost that simply redirects to cfg, which is assumed to
 // be the HTTPS configuration. The returned configuration is set
-// to listen on port 80. The TLS field of cfg must not be nil.
+// to listen on HTTPPort. The TLS field of cfg must not be nil.
 func redirPlaintextHost(cfg *SiteConfig) *SiteConfig {
 	redirPort := cfg.Addr.Port
-	if redirPort == "443" {
-		// default port is redundant
-		redirPort = ""
+	if redirPort == DefaultHTTPSPort {
+		redirPort = "" // default port is redundant
 	}
 	redirMiddleware := func(next Handler) Handler {
 		return HandlerFunc(func(w http.ResponseWriter, r *http.Request) (int, error) {
-			toURL := "https://" + r.Host
-			if redirPort != "" {
-				toURL += ":" + redirPort
+			toURL := "https://"
+			if redirPort == "" {
+				toURL += cfg.Addr.Host // don't use r.Host as it may have a port included
+			} else {
+				toURL += net.JoinHostPort(cfg.Addr.Host, redirPort)
 			}
 			toURL += r.URL.RequestURI()
 			w.Header().Set("Connection", "close")
@@ -155,12 +156,13 @@ func redirPlaintextHost(cfg *SiteConfig) *SiteConfig {
 		})
 	}
 	host := cfg.Addr.Host
-	port := "80"
+	port := HTTPPort
 	addr := net.JoinHostPort(host, port)
 	return &SiteConfig{
 		Addr:       Address{Original: addr, Host: host, Port: port},
 		ListenHost: cfg.ListenHost,
 		middleware: []Middleware{redirMiddleware},
-		TLS:        &caddytls.Config{AltHTTPPort: cfg.TLS.AltHTTPPort},
+		TLS:        &caddytls.Config{AltHTTPPort: cfg.TLS.AltHTTPPort, AltTLSSNIPort: cfg.TLS.AltTLSSNIPort},
+		Timeouts:   cfg.Timeouts,
 	}
 }
diff --git a/caddyhttp/httpserver/https_test.go b/caddyhttp/httpserver/https_test.go
index 04a4db1e..04dcbaea 100644
--- a/caddyhttp/httpserver/https_test.go
+++ b/caddyhttp/httpserver/https_test.go
@@ -11,7 +11,7 @@ import (
 func TestRedirPlaintextHost(t *testing.T) {
 	cfg := redirPlaintextHost(&SiteConfig{
 		Addr: Address{
-			Host: "example.com",
+			Host: "foohost",
 			Port: "1234",
 		},
 		ListenHost: "93.184.216.34",
@@ -19,7 +19,7 @@ func TestRedirPlaintextHost(t *testing.T) {
 	})
 
 	// Check host and port
-	if actual, expected := cfg.Addr.Host, "example.com"; actual != expected {
+	if actual, expected := cfg.Addr.Host, "foohost"; actual != expected {
 		t.Errorf("Expected redir config to have host %s but got %s", expected, actual)
 	}
 	if actual, expected := cfg.ListenHost, "93.184.216.34"; actual != expected {
@@ -38,7 +38,7 @@ func TestRedirPlaintextHost(t *testing.T) {
 
 	// Check redirect for correctness
 	rec := httptest.NewRecorder()
-	req, err := http.NewRequest("GET", "http://foo/bar?q=1", nil)
+	req, err := http.NewRequest("GET", "http://foohost/bar?q=1", nil)
 	if err != nil {
 		t.Fatal(err)
 	}
@@ -52,17 +52,17 @@ func TestRedirPlaintextHost(t *testing.T) {
 	if rec.Code != http.StatusMovedPermanently {
 		t.Errorf("Expected status %d but got %d", http.StatusMovedPermanently, rec.Code)
 	}
-	if got, want := rec.Header().Get("Location"), "https://foo:1234/bar?q=1"; got != want {
+	if got, want := rec.Header().Get("Location"), "https://foohost:1234/bar?q=1"; got != want {
 		t.Errorf("Expected Location: '%s' but got '%s'", want, got)
 	}
 
 	// browsers can infer a default port from scheme, so make sure the port
 	// doesn't get added in explicitly for default ports like 443 for https.
-	cfg = redirPlaintextHost(&SiteConfig{Addr: Address{Host: "example.com", Port: "443"}, TLS: new(caddytls.Config)})
+	cfg = redirPlaintextHost(&SiteConfig{Addr: Address{Host: "foohost", Port: "443"}, TLS: new(caddytls.Config)})
 	handler = cfg.middleware[0](nil)
 
 	rec = httptest.NewRecorder()
-	req, err = http.NewRequest("GET", "http://foo/bar?q=1", nil)
+	req, err = http.NewRequest("GET", "http://foohost/bar?q=1", nil)
 	if err != nil {
 		t.Fatal(err)
 	}
@@ -76,7 +76,7 @@ func TestRedirPlaintextHost(t *testing.T) {
 	if rec.Code != http.StatusMovedPermanently {
 		t.Errorf("Expected status %d but got %d", http.StatusMovedPermanently, rec.Code)
 	}
-	if got, want := rec.Header().Get("Location"), "https://foo/bar?q=1"; got != want {
+	if got, want := rec.Header().Get("Location"), "https://foohost/bar?q=1"; got != want {
 		t.Errorf("Expected Location: '%s' but got '%s'", want, got)
 	}
 }
diff --git a/caddyhttp/httpserver/plugin.go b/caddyhttp/httpserver/plugin.go
index 7736fcf3..4c7caa3e 100644
--- a/caddyhttp/httpserver/plugin.go
+++ b/caddyhttp/httpserver/plugin.go
@@ -19,6 +19,8 @@ import (
 const serverType = "http"
 
 func init() {
+	flag.StringVar(&HTTPPort, "http-port", HTTPPort, "Default port to use for HTTP")
+	flag.StringVar(&HTTPSPort, "https-port", HTTPSPort, "Default port to use for HTTPS")
 	flag.StringVar(&Host, "host", DefaultHost, "Default host")
 	flag.StringVar(&Port, "port", DefaultPort, "Default port")
 	flag.StringVar(&Root, "root", DefaultRoot, "Root path of default site")
@@ -119,11 +121,25 @@ func (h *httpContext) InspectServerBlocks(sourceFile string, serverBlocks []cadd
 				addr.Port = Port
 			}
 
+			// If default HTTP or HTTPS ports have been customized,
+			// make sure the ACME challenge ports match
+			var altHTTPPort, altTLSSNIPort string
+			if HTTPPort != DefaultHTTPPort {
+				altHTTPPort = HTTPPort
+			}
+			if HTTPSPort != DefaultHTTPSPort {
+				altTLSSNIPort = HTTPSPort
+			}
+
 			// Save the config to our master list, and key it for lookups
 			cfg := &SiteConfig{
-				Addr:            addr,
-				Root:            Root,
-				TLS:             &caddytls.Config{Hostname: addr.Host},
+				Addr: addr,
+				Root: Root,
+				TLS: &caddytls.Config{
+					Hostname:      addr.Host,
+					AltHTTPPort:   altHTTPPort,
+					AltTLSSNIPort: altTLSSNIPort,
+				},
 				originCaddyfile: sourceFile,
 			}
 			h.saveConfig(key, cfg)
@@ -154,7 +170,7 @@ func (h *httpContext) MakeServers() ([]caddy.Server, error) {
 		if !cfg.TLS.Enabled {
 			continue
 		}
-		if cfg.Addr.Port == "80" || cfg.Addr.Scheme == "http" {
+		if cfg.Addr.Port == HTTPPort || cfg.Addr.Scheme == "http" {
 			cfg.TLS.Enabled = false
 			log.Printf("[WARNING] TLS disabled for %s", cfg.Addr)
 		} else if cfg.Addr.Scheme == "" {
@@ -169,7 +185,7 @@ func (h *httpContext) MakeServers() ([]caddy.Server, error) {
 			// this is vital, otherwise the function call below that
 			// sets the listener address will use the default port
 			// instead of 443 because it doesn't know about TLS.
-			cfg.Addr.Port = "443"
+			cfg.Addr.Port = HTTPSPort
 		}
 	}
 
@@ -270,7 +286,7 @@ func (a Address) String() string {
 	}
 	scheme := a.Scheme
 	if scheme == "" {
-		if a.Port == "443" {
+		if a.Port == HTTPSPort {
 			scheme = "https"
 		} else {
 			scheme = "http"
@@ -282,8 +298,8 @@ func (a Address) String() string {
 	}
 	s += a.Host
 	if a.Port != "" &&
-		((scheme == "https" && a.Port != "443") ||
-			(scheme == "http" && a.Port != "80")) {
+		((scheme == "https" && a.Port != DefaultHTTPSPort) ||
+			(scheme == "http" && a.Port != DefaultHTTPPort)) {
 		s += ":" + a.Port
 	}
 	if a.Path != "" {
@@ -327,9 +343,9 @@ func standardizeAddress(str string) (Address, error) {
 	// see if we can set port based off scheme
 	if port == "" {
 		if u.Scheme == "http" {
-			port = "80"
+			port = HTTPPort
 		} else if u.Scheme == "https" {
-			port = "443"
+			port = HTTPSPort
 		}
 	}
 
@@ -339,17 +355,17 @@ func standardizeAddress(str string) (Address, error) {
 	}
 
 	// error if scheme and port combination violate convention
-	if (u.Scheme == "http" && port == "443") || (u.Scheme == "https" && port == "80") {
+	if (u.Scheme == "http" && port == HTTPSPort) || (u.Scheme == "https" && port == HTTPPort) {
 		return Address{}, fmt.Errorf("[%s] scheme and port violate convention", input)
 	}
 
 	// standardize http and https ports to their respective port numbers
 	if port == "http" {
 		u.Scheme = "http"
-		port = "80"
+		port = HTTPPort
 	} else if port == "https" {
 		u.Scheme = "https"
-		port = "443"
+		port = HTTPSPort
 	}
 
 	return Address{Original: input, Scheme: u.Scheme, Host: host, Port: port, Path: u.Path}, err
@@ -477,6 +493,10 @@ const (
 	DefaultPort = "2015"
 	// DefaultRoot is the default root folder.
 	DefaultRoot = "."
+	// DefaultHTTPPort is the default port for HTTP.
+	DefaultHTTPPort = "80"
+	// DefaultHTTPSPort is the default port for HTTPS.
+	DefaultHTTPSPort = "443"
 )
 
 // These "soft defaults" are configurable by
@@ -499,4 +519,10 @@ var (
 
 	// QUIC indicates whether QUIC is enabled or not.
 	QUIC bool
+
+	// HTTPPort is the port to use for HTTP.
+	HTTPPort = DefaultHTTPPort
+
+	// HTTPSPort is the port to use for HTTPS.
+	HTTPSPort = DefaultHTTPSPort
 )
diff --git a/caddytls/client.go b/caddytls/client.go
index 852fbe42..d1c3295e 100644
--- a/caddytls/client.go
+++ b/caddytls/client.go
@@ -112,33 +112,39 @@ var newACMEClient = func(config *Config, allowPrompts bool) (*ACMEClient, error)
 		// Use HTTP and TLS-SNI challenges by default
 
 		// See if HTTP challenge needs to be proxied
-		useHTTPPort := "" // empty port value will use challenge default
-		if caddy.HasListenerWithAddress(net.JoinHostPort(config.ListenHost, HTTPChallengePort)) {
+		useHTTPPort := HTTPChallengePort
+		if config.AltHTTPPort != "" {
 			useHTTPPort = config.AltHTTPPort
-			if useHTTPPort == "" {
-				useHTTPPort = DefaultHTTPAlternatePort
-			}
+		}
+		if caddy.HasListenerWithAddress(net.JoinHostPort(config.ListenHost, useHTTPPort)) {
+			useHTTPPort = DefaultHTTPAlternatePort
+		}
+
+		// See which port TLS-SNI challenges will be accomplished on
+		useTLSSNIPort := TLSSNIChallengePort
+		if config.AltTLSSNIPort != "" {
+			useTLSSNIPort = config.AltTLSSNIPort
 		}
 
 		// Always respect user's bind preferences by using config.ListenHost.
-		// NOTE(Sep'16): At time of writing, SetHTTPAddress() and SetTLSaddress()
+		// NOTE(Sep'16): At time of writing, SetHTTPAddress() and SetTLSAddress()
 		// must be called before SetChallengeProvider(), since they reset the
 		// challenge provider back to the default one!
 		err := c.acmeClient.SetHTTPAddress(net.JoinHostPort(config.ListenHost, useHTTPPort))
 		if err != nil {
 			return nil, err
 		}
-		err = c.acmeClient.SetTLSAddress(net.JoinHostPort(config.ListenHost, ""))
+		err = c.acmeClient.SetTLSAddress(net.JoinHostPort(config.ListenHost, useTLSSNIPort))
 		if err != nil {
 			return nil, err
 		}
 
 		// See if TLS challenge needs to be handled by our own facilities
-		if caddy.HasListenerWithAddress(net.JoinHostPort(config.ListenHost, TLSSNIChallengePort)) {
+		if caddy.HasListenerWithAddress(net.JoinHostPort(config.ListenHost, useTLSSNIPort)) {
 			c.acmeClient.SetChallengeProvider(acme.TLSSNI01, tlsSniSolver{})
 		}
 	} else {
-		// Otherwise, DNS challenge it is
+		// Otherwise, use DNS challenge exclusively
 
 		// Load provider constructor function
 		provFn, ok := dnsProviders[config.DNSProvider]
diff --git a/caddytls/config.go b/caddytls/config.go
index d6d77999..a1be44ae 100644
--- a/caddytls/config.go
+++ b/caddytls/config.go
@@ -84,6 +84,12 @@ type Config struct {
 	// coming in on port 80 to this alternate port
 	AltHTTPPort string
 
+	// The alternate port (ONLY port, not host)
+	// to use for the ACME TLS-SNI challenge.
+	// The system must forward the standard port
+	// for the TLS-SNI challenge to this port.
+	AltTLSSNIPort string
+
 	// The string identifier of the DNS provider
 	// to use when solving the ACME DNS challenge
 	DNSProvider string
@@ -479,11 +485,11 @@ var defaultCurves = []tls.CurveID{
 
 const (
 	// HTTPChallengePort is the officially designated port for
-	// the HTTP challenge.
+	// the HTTP challenge according to the ACME spec.
 	HTTPChallengePort = "80"
 
 	// TLSSNIChallengePort is the officially designated port for
-	// the TLS-SNI challenge.
+	// the TLS-SNI challenge according to the ACME spec.
 	TLSSNIChallengePort = "443"
 
 	// DefaultHTTPAlternatePort is the port on which the ACME