Hi, with both fibers server and (web server) there is a split between IPv4 and IPv6: IPv4: (fibers:run-server handler-with-path #:family AF_INET #:port port #:addr INADDR_ANY) (run-server handler-with-path 'http `(#:host "localhost" #:family ,AF_INET #:addr ,INADDR_ANY #:port ,port)) IPv6: (define s (let ((s (socket AF_INET6 SOCK_STREAM 0))) (setsockopt s SOL_SOCKET SO_REUSEADDR 1) (bind s AF_INET6 (inet-pton AF_INET6 ip) port) s)) (fibers:run-server handler-with-path #:family AF_INET6 #:port port #:addr (inet-pton AF_INET6 ip) #:socket s) (define s (let ((s (socket AF_INET6 SOCK_STREAM 0))) (setsockopt s SOL_SOCKET SO_REUSEADDR 1) (bind s AF_INET6 (inet-pton AF_INET6 ip) port) s)) (run-server handler-with-path 'http `(#:family ,AF_INET6 #:addr (inet-pton AF_INET6 ip) #:port ,port #:socket ,s)) Is there a way to bind to both IPv6 and IPv4, so my server will react to requests regardless of whether a client reaches my computer over IPv4 or IPv6? Best wishes, Arne -- Unpolitisch sein heißt politisch sein, ohne es zu merken. draketo.de