I was accessing a site daily until this morning. Now I cannot ping the site through ping on my pfsense firewall or on a client behind the firewall. I have made no changes to the firewall.
If I bypass the firewall I can access the site OK https://www.ncbi.nlm.nih.gov.
Running wireshark from a client I can see the DNS request:
Info: Standard query 0x0cf2 Server failure A https://www.ncbi.nlm.nih.gov
I tried changing the default (empty) nameservers in pfsense to 126.96.36.199, 188.8.131.52 and 184.108.40.206 (all 3, in that order), but this made no difference.
I cleared the arp table, rebooted pfsense.
I cant see any blocks in the firewall on the website i am accessing.
If I filter the firewall logs on the destination IP address 220.127.116.11 I can see WAN rule 'let out anything from firewall host itself - ICMP and UDP' and I can resolve the URL in the table.
Here is ping result from Diagnostics/Ping in pfsense:
PING 18.104.22.168 (22.214.171.124) from my_internal_LAN_IP: 56 data bytes
--- 126.96.36.199 ping statistics --- 5 packets transmitted, 0 packets received, 100.0% packet loss
If I do DNS Lookup from pfsense using the IP as hostname O get the website URL - so that works OK
Result Record type www.ncbi.nlm.nih.gov PTR Timings Name server Query time 127.0.0.1 194 msec
If I do traceroute to hostname 188.8.131.52 in pfsense, I can see hop out to my ISP then 14 more hops around the ISP then it stops. But when I connect without going through pfsense I can connect fine.