fix dhcp6.py bug using python3
@@ -222,7 +222,7 @@ class options(stringify.StringifyMixin):
return cls(opt_parse_list, len(buf))
def serialize(self):
- seri_opt = ""
+ seri_opt = bytes()
for opt in self.option_list:
seri_opt += opt.serialize()
if self.options_len == 0:
