Dec 8 13:35:18 kernel: [6114223.972059] Peer unexpectedly shrunk window 3517493258:3517493263 (repaired)
Dec 8 13:35:20 kernel: [6114225.860020] Peer unexpectedly shrunk window 4250428389:4250428394 (repaired)
# nano /etc/fail2ban/filter.d/shrunk-window.conf
[Definition]
failregex = ^.*Peer \:.* unexpectedly shrunk window.*repaired+
ignoreregex =
# nano /etc/fail2ban/jail.conf
[shrunk-window]
enabled = true
filter = shrunk-window
logpath = /var/log/kern.log
port = all
maxretry = 1
nano /etc/fail2ban/jail.local
[shrunk-window]
enabled = true
filter = shrunk-window
logpath = /var/log/kern.log
port = all
maxretry = 1
/etc/init.d/fail2ban restart