diff --git a/echo-client.rkt b/echo-client.rkt
index 94b91f9..032fd74 100644
--- a/echo-client.rkt
+++ b/echo-client.rkt
@@ -7,9 +7,17 @@
 
 (define server-entry-name (standard-logbook-entry-name))
 (define server-entry-type #f)
+(define server-hostname "localhost")
+(define server-port 5999)
 
 (command-line #:program "echo-client.rkt"
 	      #:once-each
+	      ["--host" name
+	       "set hostname of server to contact"
+	       (set! server-hostname name)]
+	      ["--port" number
+	       "set TCP port of server to contact"
+	       (set! server-port (string->number number))]
 	      ["--logbook-entry-name" name
 	       "set logbook entry name to use when recording run statistics"
 	       (set! server-entry-name name)]
@@ -73,7 +81,7 @@
 (define (start-connection)
   (define i next-connection-id)
   (set! next-connection-id (+ i 1))
-  (define-values (in out) (tcp-connect "localhost" 5999))
+  (define-values (in out) (tcp-connect server-hostname server-port))
   (set! connections (hash-set connections i (c in out))))
 
 ;; Ping random connections for ping-time milliseconds.
diff --git a/external-latency.rkt b/external-latency.rkt
index 3b7185b..425a59b 100644
--- a/external-latency.rkt
+++ b/external-latency.rkt
@@ -8,8 +8,11 @@
 (require logbook)
 
 (define server-variation #f)
+(define server-hostname "localhost")
 
 (command-line #:program "external-latency.rkt"
+	      #:once-each
+	      ["--host" name "hostname where server is reachable" (set! server-hostname name)]
 	      #:once-any
 	      ["--erlang" "use erlang server" (set! server-variation 'erlang)]
 	      ["--minimart" "use minimart server" (set! server-variation 'minimart)])
@@ -54,7 +57,8 @@
 (log-info "Starting client...")
 (define client-control
   (start-bg
-   (format "racket echo-client.rkt --logbook-entry-name ~a --logbook-entry-type ~a"
+   (format "racket echo-client.rkt --host ~a --logbook-entry-name ~a --logbook-entry-type ~a"
+	   server-hostname
 	   entry-name
 	   entry-type)))