Converting network and gateway from routing table to hexadecimal string - Mikrotik Script
Version of the script giving result as DHCP option 121 (RFC 3442)

# Second script converting network and gateway from routing table to hexadecimal string
# according to RFC 3442 - DHCP option 121
# result=0x
# example: dst-address=192.168.2.0/24 gateway=192.168.1.1 => result=0x18c0a802c0a80101
#
# Network can have 0 to 4 octets:
# Width of subnet mask     Number of significant octets
#              0                     0
#           1- 8                     1
#           9-16                     2
#          17-24                     3
#          25-32                     4
#
# (c) Daniel Starnowski 2011
#
:foreach route in=[/ip route find] do={
:local dst [/ip route get $route dst-address];
:local gateway [/ip route get $route gateway];
:if ($gateway=[:toip $gateway]) do={
  :local total ($dst . "." . $gateway);
  :local result "0x";
  :local hextable [:toarray "0,1,2,3,4,5,6,7,8,9,a,b,c,d,e,f"];
  :local total2 "";
  :local decimal;
  :local division;
  :local i;
  :local j;
  :for i from=1 to=[:len $total] step=1 do={
   :set j [:pick $total ($i-1) $i];
   :if (($j=".") or ($j="/")) do={:set j ","};
   :set total2 ($total2 . $j);
   };
  :set total2 [:toarray $total2];

  :set decimal [:pick $total2 4]
  :set division ($decimal / 16);
  :set result ($result . [:pick $hextable $division]);
  :set result ($result . [:pick $hextable ($decimal - (16 * $division))]);
  :local omit ((32-[:pick $total2 4]) / 8);

  :for i from=($omit+1) to=8 step=1 do={
   :set j $i;
   :if ($j<5) do={:set j ($j-1-$omit);};
   :set decimal [:pick $total2 $j]
   :set division ($decimal / 16);
   :set result ($result . [:pick $hextable $division]);
   :set result ($result . [:pick $hextable ($decimal - (16 * $division))]);
   };
  :put ($result . " for " . $dst);
} else={:put ("Gateway is not a single IP address for ".$dst);}
}

Version of the script with full 4 bytes of destination network

# Script converting network and gateway from routing table to hexadecimal string
# dst-address=192.168.2.0/24 gateway=192.168.1.1 => result=0x18c0a80200c0a80101
#
# (c) Daniel Starnowski 2011
#
:foreach route in=[/ip route find] do={
:local dst [/ip route get $route dst-address];
:local gateway [/ip route get $route gateway];
:if ($gateway=[:toip $gateway]) do={
  :local total ($dst . "." . $gateway);
  :local result "0x";
  :local hextable [:toarray "0,1,2,3,4,5,6,7,8,9,a,b,c,d,e,f"];
  :local total2 "";
  :local decimal;
  :local division;
  :local i;
  :local j;
  :for i from=1 to=[:len $total] step=1 do={
   :set j [:pick $total ($i-1) $i];
   :if (($j=".") or ($j="/")) do={:set j ","};
   :set total2 ($total2 . $j);
   };
  :set total2 [:toarray $total2];

  :for i from=0 to=8 step=1 do={
   :set j $i;
   :if ($j<5) do={if ($j=0) do={:set j 4;} else={:set j ($j-1);};};
   :set decimal [:pick $total2 $j ($j+1)]
   :set division ($decimal / 16);
   :set result ($result . [:pick $hextable $division]);
   :set result ($result . [:pick $hextable ($decimal - (16 * $division))]);
   };
  :put $result;
} else={:put ("Gateway is not a single IP address for ".$dst);}
}