Core issue
This issue occurs when there is a Domain Name System (DNS) problem with the Internet Service Provider (ISP) DNS server IP address.
Resolution
To resolve this issue, perform these steps:
- Make sure that the Internet Control Message Protocol (ICMP) requests go through. This is a good test for connectivity.
- To facilitate ICMP, create an Access Control List (ACL) ICMP for any outside interface or access group.
- Try to browse web sites through the DNS, or through the IP address.
If this is not possible, there is a DNS issue.
- Try a different DNS server, other than the one provided by the ISP.
If browsing works properly, contact the ISP to find out why the DNS server is does not function correctly.