We've received two calls complaining about access to www.ebay.com. Further checking shows that none of our DNS servers can resolve either www.ebay.com or ebay.com. DIG returns a "timed out". Flushing our caches made no difference, and our upstream provider's DNS servers are acting the same way. Digging against 8.8.8.8 works fine, but against the 4 NS servers listed for ebay, they don't, probably because their DNS server is all ebaydns.com. nagios:/tmp# dig A ebay.com @96.31.0.5 ; <<>> DiG 9.7.3 <<>> A ebay.com @96.31.0.5 ;; global options: +cmd ;; connection timed out; no servers could be reached nagios:/tmp# dig A ebay.com @167.142.225.5 ; <<>> DiG 9.7.3 <<>> A ebay.com @167.142.225.5 ;; global options: +cmd ;; Got answer: ;; ->>HEADER<<- opcode: QUERY, status: SERVFAIL, id: 41569 ;; flags: qr rd ra; QUERY: 1, ANSWER: 0, AUTHORITY: 0, ADDITIONAL: 0 ;; QUESTION SECTION: ;ebay.com. IN A ;; Query time: 4433 msec ;; SERVER: 167.142.225.5#53(167.142.225.5) ;; WHEN: Tue Jan 17 14:19:12 2012 ;; MSG SIZE rcvd: 26 nagios:/tmp# nagios:/tmp# dig NS ebay.com @8.8.8.8 ; <<>> DiG 9.7.3 <<>> NS ebay.com @8.8.8.8 ;; global options: +cmd ;; Got answer: ;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 58612 ;; flags: qr rd ra; QUERY: 1, ANSWER: 4, AUTHORITY: 0, ADDITIONAL: 0 ;; QUESTION SECTION: ;ebay.com. IN NS ;; ANSWER SECTION: ebay.com. 63033 IN NS sjc-dns2.ebaydns.com. ebay.com. 63033 IN NS smf-dns2.ebaydns.com. ebay.com. 63033 IN NS smf-dns1.ebaydns.com. ebay.com. 63033 IN NS sjc-dns1.ebaydns.com. ;; Query time: 37 msec ;; SERVER: 8.8.8.8#53(8.8.8.8) ;; WHEN: Tue Jan 17 14:18:22 2012 ;; MSG SIZE rcvd: 126 nagios:/tmp#