i have a router cisco 871 configured with nat and access list for filtering the internet traffic. I have published a windows 2003 dns server on public ip fixed without filter of accesslist. When i try to transfer the dns zone to another external server the process fail. I try to scan the dns port of server published: TCP port 53 responding, but no UDP port 53. Why?
Perhaps if you post the configuration of the 871 we might identify the reason that UDP port 53 is not responding. The things that I would look for first would be possible issues with the access list or possible issues in address translation. But there might be other causes of the problem.
We are pleased to announce availability of Beta software for 16.6.3.
16.6.3 will be the second rebuild on the 16.6 release train targeted
towards Catalyst 9500/9400/9300/3850/3650 switching platforms. We are
looking for early feedback from customers befor...
Introduction Featured Speakers Luis Espejel is the Telecommunications
Manager of IENova, an Oil & Gas company. Currently he works with Cisco
IOS® and Cisco IOS XE platforms, and NX to some extent. He has also
worked as a Senior Engineer with the Routing P...
In this session you can learn more about Layer 3 multicast and the best
practices to identify possible threats and take security measures. It
provides an overview of basic multicast, the best security practices for
use of this technology, and recommendati...