Воспроизвелось прошлой ночью, началось в 2:56MSK. На момент разбора (~10:30MSK) drweb.com через наши NS не резолвился - закэшировался отрицательный ответ. Запрос напрямую к NS, авторитетным для drweb.com, проходил:
[sysadm@gate2 ~]$ host esuite.geo.drweb.com
Host esuite.geo.drweb.com not found: 3(NXDOMAIN)
[sysadm@gate2 ~]$ host esuite.geo.drweb.com dual2
Using domain server:
Name: dual2
Address: 172.16.80.5#53
Aliases:
Host esuite.geo.drweb.com not found: 3(NXDOMAIN)
[sysadm@gate2 ~]$ host -t NS geo.drweb.com
Host geo.drweb.com not found: 3(NXDOMAIN)
[sysadm@gate2 ~]$ host -t NS drweb.com
Host drweb.com not found: 3(NXDOMAIN)
[sysadm@gate2 ~]$ host -t ANY drweb.com 31.44.85.37
;; Truncated, retrying in TCP mode.
Using domain server:
Name: 31.44.85.37
Address: 31.44.85.37#53
Aliases:
drweb.com descriptive text "v=spf1 +a +mx ip4:217.16.18.217/32 ip4:87.242.72.66/32 ip4:217.16.26.90/32 ip4:92.242.41.84/32" " ip4:87.242.75.178/32 ip4:87.242.79.77/32 ip4:213.79.64.32/27 ip4:213.79.65.32/27 ip4:213.79.64.0/28" " ip4:213.79.65.0/28 ip4:84.204.76.96/27 ip4:81.176.67.172/32 ip4:217.16.18.217/32 ip4:195.88.252.0/25 ip4:195.88.253.0/25" " ip4:85.10.195.208/32 ip4:153.120.124.225/32 ip4:178.57.75.4/32" " ip4:217.16.26.139/32 ip4:213.79.65.51/32 ip4:92.242.41.88/32 ip4:92.242.41.85/32 ip4:213.79.65.55 ip4:85.10.195.208/32 ~all"
drweb.com has SPF record "v=spf1 +a +mx ip4:217.16.18.217/32 ip4:87.242.72.66/32 ip4:217.16.26.90/32 ip4:92.242.41.84/32" " ip4:87.242.75.178/32 ip4:87.242.79.77/32 ip4:213.79.64.32/27 ip4:213.79.65.32/27 ip4:213.79.64.0/28" " ip4:213.79.65.0/28 ip4:84.204.76.96/27 ip4:81.176.67.172/32 ip4:217.16.18.217/32 ip4:195.88.252.0/25 ip4:195.88.253.0/25" " ip4:85.10.195.208/32 ip4:153.120.124.225/32 ip4:178.57.75.4/32" " ip4:217.16.26.139/32 ip4:213.79.65.51/32 ip4:92.242.41.88/32 ip4:92.242.41.85/32 ip4:213.79.65.55 ip4:85.10.195.208/32 ~all"
drweb.com has address 178.248.233.94
drweb.com has SOA record rns01.drweb.com. root.drweb.com. 2019041800 3600 900 1209600 3600
drweb.com name server rns02.drweb.com.
drweb.com name server rns01.drweb.com.
drweb.com mail is handled by 10 relay.drweb.com.
drweb.com mail is handled by 10 relay2.drweb.com.
Решилось принудительной очисткой кэша наших серверов имен