interface set sfp-sfpplus1 disabled=yes
delay 5
interface set sfp-sfpplus1 disabled=no

[admin@MikroTik] /system> script print
Flags: I - invalid
 0   ;;; reset sfp1 port to fix glitch with sfp
     name="startup-script" owner="admin" policy=ftp,reboot,read,write,policy,test,password,sniff,sensitive,romon
     dont-require-permissions=no run-count=0 source=
       interface set sfp-sfpplus1 disabled=yes
       delay 5
       interface set sfp-sfpplus1 disabled=no
[admin@MikroTik] /system> schedule
[admin@MikroTik] /system scheduler>

.. -- go up to system
add -- Create a new item
comment -- Set comment for items
disable -- Disable items
edit --
enable -- Enable items
export -- Print or save an export script that can be used to restore configuration
find -- Find items by value
get -- Gets value of item's property
print -- Print values of item properties
remove -- Remove item
set -- Change item properties


[admin@MikroTik] /system scheduler> print
Flags: X - disabled
 #   NAME                  START-DATE  START-TIME                INTERVAL             ON-EVENT                 RUN-COUNT
 0   startup-script                    startup                   0s                   startup startup-script           0
[admin@MikroTik] /system scheduler> ..
[admin@MikroTik] /system> ..

:local HOST "192.168.1.1"
:local PINGCOUNT "10"
:local INTF "sfp-sfpplus1"
:local DELAY "3s"
:log info "Delay 10s."
:delay 10s
:log info "Start pinging $INTF."
:if ([/ping $HOST interval=1 count=$PINGCOUNT] = 0) do={
:log error "Interface $INTF is down, restarting..."
/interface ethernet set $INTF auto-negotiation=no
:delay $DELAY
/interface ethernet set $INTF auto-negotiation=yes
:log warning "$INTF restart complete."
} else={
:log info "$INTF is working."
}