On Fri, Sep 14, 2018 at 4:24 PM Daniel J. Luke <dl...@geeklair.net> wrote: > > On Sep 14, 2018, at 3:26 PM, Kevin A. McGrail <kmcgr...@apache.org> wrote: > > On 9/14/2018 3:22 PM, Alex wrote: > >> I wish it were that easy. /etc/resolv.conf is set up to use 127.0.0.1, > >> which is bind configured as a my local caching resolver. > > Sinister issues like this are hard. I'll try and escalate our plans for > > rsync access. > > Alex - have you looked at bad checksum counters on the host? (netstat -s) - > I've seen strange issues before with broken network hardware (or bugs in > switch/router code) caused changes to packets as they passed through the > 'bad' device. The first hints were those counters increasing at the same time > as the mysterious issue happening.
I don't see anything relating to bad checksums with netstat :-( I've also tried numerous ethtool config changes. I've also looked through hundreds of packets with tcpdump and wireshark. This isn't a spamassassin message, but does anyone with a postfix system ever see similar "Name service error" messages such as the one below? Sep 14 21:12:54 mail03 postfix/dnsblog[3713]: warning: dnsblog_query: lookup error for DNS query 239.242.238.54.ubl.unsubscore.com: Host or domain name not found. Name service error for name=239.242.238.54.ubl.unsubscore.com type=A: Host not found, try again It appears to occur quite frequently, and on multiple unrelated systems. I'd love to find out what's causing it. The postfix people ascribed it to a remote server problem, but I can't believe virtually all RBLs, including spamhaus, would have such intermittent problems with *their* name servers.
