As a number of DNS records with short TTL grows, the bind from RHL7.3 (fully updated from fedoralegacy.org) is almost unusable. This short-term records are not refreshed after expiration so some Web addresses are unreachable: # cat /etc/resolv.conf nameserver 127.0.0.1 # dig download.fedoralegacy.org ... ;; QUESTION SECTION: ;download.fedoralegacy.org. IN A ... (ie this DNS question failed as non-existed, other DNS queries works) # /etc/init.d/named restart ... (bind restarted) # dig download.fedoralegacy.org ... ;; ANSWER SECTION: download.fedoralegacy.org. 1913 IN CNAME legacy.linux.duke.edu. legacy.linux.duke.edu. 1800 IN A 152.3.183.83 ... I reported this as the bug #65470 but it has been never fixed. I RHL7.3 days I workarounded this bug by using own recent version of bind. After the TTL expiration bind sometimes enter to this state. As fedoralegacy.org has short term TTLs now, yum autoupdates does not work.
Unfortunately not really a security issue. If you have a patch that applies to RHL7.3's bind we could include it if we ever have to update bind.