Possibly due to firewall. If not firewall then simply check whether there is any inbound ACL configured on your WAN interface or not. If there is one, try removing it and telnet from Internet. If works then you know that you'll have to edit your ACL to permit telnet. BTW, I do not recommend telnet on WAN/Internet interface. Since your IOS can do k9, check and see if you have SSH enabled or not. Once enabled, SSH to your router instead.
There's also a possibility of routing issue which might have default route pointing straight out of the WAN interface for your LAN network. Quite a lot os possibility here.
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...