对2.96的防火墙规则疑问，高手帮帮

suqunmu

1. unicast是什么意思？
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add chain=input dst-address-type=!local action=drop comment="drop all that is not to \
    local" disabled=no
add chain=input src-address-type=!unicast action=drop comment="drom all that is not from \
    unicast" disabled=no   
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2。icmp部分 看不懂
－－－－－－－－－－－－－－－－－－－－－－－－－－－－－－－－－－－－－－－－－－－－
add chain=input protocol=icmp action=jump jump-target=ICMP comment="jump to chain ICMP" \
    disabled=no
add chain=input action=jump jump-target=services comment="jump to chain services" \
    disabled=no
add chain=input action=drop comment="drop everything else" disabled=no


add chain=ICMP protocol=icmp icmp-options=0:0-255 limit=5,5 action=accept comment="0:0 \
    and limit for 5pac/s" disabled=no
add chain=ICMP protocol=icmp icmp-options=3:3 limit=5,5 action=accept comment="3:3 and \
    limit for 5pac/s" disabled=no
add chain=ICMP protocol=icmp icmp-options=3:4 limit=5,5 action=accept comment="3:4 and \
    limit for 5pac/s" disabled=no
add chain=ICMP protocol=icmp icmp-options=8:0-255 limit=5,5 action=accept comment="8:0 \
    and limit for 5pac/s" disabled=no
add chain=ICMP protocol=icmp icmp-options=11:0-255 limit=5,5 action=accept comment="11:0 \
    and limit for 5pac/s" disabled=no
add chain=ICMP protocol=icmp action=drop comment="Drop everything else" disabled=no
add chain=services src-address=127.0.0.1 dst-address=127.0.0.1 action=accept \
    comment="accept localhost" disabled=no   
帮帮大概解释下