Hi Alex, What does your query volume look like on this server? Depending on volume, the BIND defaults for:
- clients-per-query - max-clients-per-query - recursive-clients - tcp-clients and others may not be set high enough. Check pp. 106-108 in the latest 9.11 manual for more details on each of these. Of course, if you're only seeing SERVFAIL for a handful of domains, then they may have some sort of delegation issue, or there might be a network issue between your caching servers and them. John On Thu, Jul 26, 2018 at 1:07 PM, Alex <mysqlstud...@gmail.com> wrote: > Hi, > > I have a bind-9.11.4 server on a fedora28 system and are frequently > seeing SERVFAIL errors like this: > > 26-Jul-2018 12:54:04.255 query-errors: info: client @0x7f764314a5c0 > 127.0.0.1#50719 (223.178.102.199.cidr.bl.mcafee.com): query failed > (SERVFAIL) for 223.178.102.199.cidr.bl.mcafee.com/IN/A at > ../../../bin/named/query.c:4140 > > I believe this happens more frequently at times of peak link > utilization, but it also appears to happen during normal times. > > This is a local caching server I've set up but it also appears to > exist on other systems that have been set up to be authoritative for > our domain. > > How can I troubleshoot this further? > > Here is the named.conf for this caching server: > > acl "trusted" { > { 127/8; }; > { 68.195.191.40/29; }; > { 192.168.1.0/24; }; > { 107.155.67.2/32; }; > }; > > options { > listen-on port 53 { 127.0.0.1; 68.195.191.45; }; > listen-on-v6 port 53 { none; }; > directory "/var/named"; > dump-file "/var/named/data/cache_dump.db"; > statistics-file "/var/named/data/named.stats"; // _PATH_STATS > memstatistics-file "/var/named/data/named.memstats"; // > _PATH_MEMSTATS > allow-query { trusted; }; > recursion yes; > zone-statistics yes; > > // dnssec-enable yes; > // dnssec-validation yes; > // dnssec-lookaside auto; > > dnssec-enable no; > dnssec-validation no; > dnssec-lookaside no; > > /* Path to ISC DLV key */ > bindkeys-file "/etc/named.iscdlv.key"; > > managed-keys-directory "/var/named/dynamic"; > > }; > > logging { > channel default_debug { > file "data/named.run"; > severity dynamic; > }; > > // Record all queries to the box for now > channel query_info { > severity info; > file "/var/log/named.query.log" versions 3 size 10m; > print-time yes; > print-category yes; > }; > > // added for fail2ban support > channel security_file { > severity dynamic; > file "/var/log/named.security.log" versions 3 size 30m; > print-time yes; > print-category yes; > }; > > channel b_debug { > file "/var/log/named.debug.log" versions 2 size 10m; > print-time yes; > print-category yes; > print-severity yes; > severity dynamic; > }; > > // Send the security related messages to a separate file. > channel audit_log { > file "/var/log/named.audit.log" versions 4 size 10m; > severity info; > print-time yes; > print-category yes; > }; > > > category queries { query_info; }; > category default { b_debug; }; > category config { b_debug; }; > category security { security_file; }; > // category lame-servers { audit_log; }; > category lame-servers { null; }; > > }; > > zone "." IN { > type hint; > file "/var/named/named.ca"; > }; > > zone "localhost.localdomain" IN { > type master; > file "named.localhost"; > allow-update { none; }; > }; > > zone "localhost" IN { > type master; > file "named.localhost"; > allow-update { none; }; > }; > > zone > "1.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.ip6.arpa" > IN { > type master; > file "named.loopback"; > allow-update { none; }; > }; > > zone "1.0.0.127.in-addr.arpa" IN { > type master; > file "named.loopback"; > allow-update { none; }; > }; > > zone "0.in-addr.arpa" IN { > type master; > file "named.empty"; > allow-update { none; }; > }; > > include "/etc/named.root.key"; > include "/etc/rndc.key"; > _______________________________________________ _______________________________________________ Please visit https://lists.isc.org/mailman/listinfo/bind-users to unsubscribe from this list bind-users mailing list bind-users@lists.isc.org https://lists.isc.org/mailman/listinfo/bind-users