有一个运行 Centos 7.9 的 VPS，主要用于 Plesk 网站托管。
最近，当我们重启服务器时，除 SSH（端口 58431）之外的所有端口都被阻止。我们必须通过 SSH 进入 VPS 并iptables --flush让网站正常运行，然后在下次重启时（通常是几天后）再次停止。
iptables --list输出如下，我完全不知道从哪里开始。有人能找出导致这种情况的规则吗？可能是什么原因导致的？
Chain PREROUTING (policy ACCEPT 4320 packets, 247K bytes)
pkts bytes target prot opt in out source destination
4322 247K PREROUTING_direct all -- * * 0.0.0.0/0 0.0.0.0/0
4322 247K PREROUTING_ZONES_SOURCE all -- * * 0.0.0.0/0 0.0.0.0/0
4322 247K PREROUTING_ZONES all -- * * 0.0.0.0/0 0.0.0.0/0
Chain POSTROUTING (policy ACCEPT 465K packets, 28M bytes)
pkts bytes target prot opt in out source destination
465K 28M POSTROUTING_direct all -- * * 0.0.0.0/0 0.0.0.0/0
465K 28M POSTROUTING_ZONES_SOURCE all -- * * 0.0.0.0/0 0.0.0.0/0
465K 28M POSTROUTING_ZONES all -- * * 0.0.0.0/0 0.0.0.0/0
Chain OUTPUT (policy ACCEPT 465K packets, 28M bytes)
pkts bytes target prot opt in out source destination
465K 28M OUTPUT_direct all -- * * 0.0.0.0/0 0.0.0.0/0
Chain OUTPUT_direct (1 references)
pkts bytes target prot opt in out source destination
Chain POSTROUTING_ZONES (1 references)
pkts bytes target prot opt in out source destination
4011 258K POST_public all -- * venet0 0.0.0.0/0 0.0.0.0/0 [goto]
461K 28M POST_public all -- * + 0.0.0.0/0 0.0.0.0/0 [goto]
Chain POSTROUTING_ZONES_SOURCE (1 references)
pkts bytes target prot opt in out source destination
Chain POSTROUTING_direct (1 references)
pkts bytes target prot opt in out source destination
Chain POST_public (2 references)
pkts bytes target prot opt in out source destination
465K 28M POST_public_log all -- * * 0.0.0.0/0 0.0.0.0/0
465K 28M POST_public_deny all -- * * 0.0.0.0/0 0.0.0.0/0
465K 28M POST_public_allow all -- * * 0.0.0.0/0 0.0.0.0/0
Chain POST_public_allow (1 references)
pkts bytes target prot opt in out source destination
Chain POST_public_deny (1 references)
pkts bytes target prot opt in out source destination
Chain POST_public_log (1 references)
pkts bytes target prot opt in out source destination
Chain PREROUTING_ZONES (1 references)
pkts bytes target prot opt in out source destination
4320 247K PRE_public all -- venet0 * 0.0.0.0/0 0.0.0.0/0 [goto]
1 52 PRE_public all -- + * 0.0.0.0/0 0.0.0.0/0 [goto]
Chain PREROUTING_ZONES_SOURCE (1 references)
pkts bytes target prot opt in out source destination
Chain PREROUTING_direct (1 references)
pkts bytes target prot opt in out source destination
Chain PRE_public (2 references)
pkts bytes target prot opt in out source destination
4321 247K PRE_public_log all -- * * 0.0.0.0/0 0.0.0.0/0
4321 247K PRE_public_deny all -- * * 0.0.0.0/0 0.0.0.0/0
4321 247K PRE_public_allow all -- * * 0.0.0.0/0 0.0.0.0/0
Chain PRE_public_allow (1 references)
pkts bytes target prot opt in out source destination
Chain PRE_public_deny (1 references)
pkts bytes target prot opt in out source destination
Chain PRE_public_log (1 references)
pkts bytes target prot opt in out source destination