First - you may be expecting a bit given 6.5.4 has been out of support for some time, and 8.1.2 doesn't officially support anything below version 7.6.
A couple of questions.
For 1. If the answer is large - then review this article and see if it applies https://www.veritas.com/support/en_US/article.100003560
For 2. If the client has IPv6 enabled, review this article (basically disable IPv6 if you are not using it) https://www.veritas.com/support/en_US/article.100022013