Change the IPV6_MAX_PREFIX_LENGTH to 128

The ipv6 prefix length could be 1 to 128

Signed-off-by: John Wang <wangzhiqiang.bj@bytedance.com>
Change-Id: I303eb835c30287df250137878f2e7d7d21c1c477
diff --git a/util.hpp b/util.hpp
index 7e1aab6..f9eb0e2 100644
--- a/util.hpp
+++ b/util.hpp
@@ -25,7 +25,7 @@
 
 constexpr auto IPV4_MIN_PREFIX_LENGTH = 1;
 constexpr auto IPV4_MAX_PREFIX_LENGTH = 32;
-constexpr auto IPV6_MAX_PREFIX_LENGTH = 64;
+constexpr auto IPV6_MAX_PREFIX_LENGTH = 128;
 constexpr auto IPV4_PREFIX = "169.254";
 constexpr auto IPV6_PREFIX = "fe80";