Ubuntu系统执行iptables-save命令无默认防火墙链规则输出的问题咨询

大家好，我碰到了一个困惑的问题：在Ubuntu 22.04.3 LTS和Ubuntu 20.04.4 LTS这两个版本的系统上，执行iptables-save命令时，看不到默认的防火墙链规则；但换到CentOS或者Red Hat这类Linux发行版上跑同样的命令，就能正常输出类似下面的默认链规则内容：

[root@rhel-8-50805-client ~]# iptables-save
# Generated by iptables-save v1.8.4 on Fri May 10 10:03:11 2024
*filter
:INPUT ACCEPT [33772:226622349]
:FORWARD ACCEPT [0:0]
:OUTPUT ACCEPT [28942:9992818]
COMMIT
# Completed on Fri May 10 10:03:11 2024
# Generated by iptables-save v1.8.4 on Fri May 10 10:03:11 2024
*security
:INPUT ACCEPT [33772:226622349]
:FORWARD ACCEPT [0:0]
:OUTPUT ACCEPT [28942:9992818]
COMMIT
# Completed on Fri May 10 10:03:11 2024
# Generated by iptables-save v1.8.4 on Fri May 10 10:03:11 2024
*raw
:PREROUTING ACCEPT [33773:226622837]
:OUTPUT ACCEPT [28942:9992818]
COMMIT
# Completed on Fri May 10 10:03:11 2024
# Generated by iptables-save v1.8.4 on Fri May 10 10:03:11 2024
*mangle
:PREROUTING ACCEPT [33773:226622837]
:INPUT ACCEPT [33772:226622349]
:FORWARD ACCEPT [0:0]
:OUTPUT ACCEPT [28942:9992818]
:POSTROUTING ACCEPT [28943:9993306]
COMMIT
# Completed on Fri May 10 10:03:11 2024

我想弄明白Ubuntu上为啥会出现这种差异，有没有办法让iptables-save也输出这些默认的链规则呢？麻烦各位有经验的朋友帮忙解答一下，万分感谢！

备注：内容来源于stack exchange，提问作者Vishal Kharade