Why I cannot access specific websites?

Zyxel_James

Scenario: There are certain websites that I cannot access, but other websites are available.

Answer: It could be ICMP TTL expired.
By default, ICSA is enabled which means the connection will terminate when ICMP is unreachable or ICMP TTL expires. So if there are too many hops, it may cause TTL to expire.

How to solve:
Disable ICSA to avoid the connection gets terminated.

Router# configure terminal
Router(config)# firewall icsa icmp-destroy-session disable