[#:promisc-on @code{#f}] [#:promisc-off @code{#f}] [#:trailers-on @code{#f}] @

  [#:trailers-off @code{#f}] [#:carrier-on @code{#f}] [#:carrier-off @code{#f}] @

  [#:txqueuelen @code{#f}] [#:name @code{#f}] [#:address @code{#f}] @

Modify an existing link and set its flags and attributes to the ones specified

by the various keywords.  When a keyword is omited, the corresponding attribute

is not changed.

@var{device} can be a device index (as a number) or a device name (as a string).

Do not set @code{#:up} and @code{#:down} at the same time.  Do not set

@end deffn

@deffn {Scheme Procedure} link-show [#:device @code{#f}] [#:group @code{#f}] @

                   (carrier-on #f) (carrier-off #f)

                   (txqueuelen #f) (name #f) (address #f)

                   (broadcast #f) (mtu #f) (netns #f)

  (define request-num (random 65535))

  (define id (if (number? device) device (link-name->index device)))

  (define netnsfd (cond

                  (make-route-attr IFLA_MTU

                    (make-u32-route-attr mtu)))

                '())

                (list

                  (make-route-attr IFLA_MASTER

                '())

          ,@(if netns

                (list