I have a new Cisco 881w router to connect my LAN to the Internet, its WAN port is connected directly to the cable modem of my ISP. For connection tests I am working directly on the router CLI via SSH. The problem now is that I can ping any host in the subnet of the IP address of the WAN port (FastEthernet4), including the gateway of my ISP, but I cannot reach/ping any other host outside this subnet. My external IP (of the WAN port) is 184.108.40.206/24, the ISP's gateway is 220.127.116.11, which I can reach (as well as any 84.112.90.x address). The DNS for example, with an IP of 18.104.22.168, is unreachable from the router.
The routing on the ISP side seems to be correct, because when I connect my notebook directly to the ISP modem (instead of the Cisco router), then the Internet connection works fine, I can access any public host/server. Also I don't think thats a NAT issue, because as said I am testing (pinging) directly from the Cisco router CLI.
I do have some understanding of IP routing in general, but unfortunately I am no Cisco IOS expert. Hence I would be glad for any hint you can give me. It's probably only a little issue for a Cisco expert. Please have a look at the attached running config of the router.
Thanks in advance for your help!
Kind regards, Matthias