Dustin C. Hatch
a0a4b91faf
The *filter* table is responsible for deciding which packets will be accepted and which will be rejected. It has three chains, which classify packets according to whether they are destined for the local machine (input), passing through this machine (forward) or originating from the local machine (output). The *dch-gw* role now configures all three chains in this table. For now, it defines basic rules, mostly based on TCP/UDP destination port: * Traffic destined for a service hosted by the local machine (DNS, DHCP, SSH), is allowed if it does not come from the Internet * Traffic passing through the machine is allowed if: * It is passing between internal networks * It is destined for a host on the FireMon network (VPN) * It was NATed to in internal host (marked 323) * It is destined for the Internet * Only DHCP, HTTP, and DNS are allowed to originate from the local machine This configuration requires an `internet_iface` variable, which indicates the name of the network interface connected to the Internet directly.
35 lines
948 B
Django/Jinja
35 lines
948 B
Django/Jinja
{#- vim: set sw=4 ts=4 sts=4 et : #}
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table inet filter {
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set allow_tcp_in {
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type inet_service
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flags interval
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elements = {
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{% for item in allow_incoming if item.protocol|d('tcp') == 'tcp' %}
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{{ item.port }},
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{% endfor %}
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}
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}
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set allow_udp_in {
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type inet_service
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flags interval
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elements = {
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{% for item in allow_incoming if item.protocol|d('tcp') == 'udp' %}
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{{ item.port }},
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{% endfor %}
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}
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}
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chain input {
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ct state established,related accept
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iif lo accept
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ip6 nexthdr ipv6-icmp accept
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ip protocol icmp accept
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udp sport dhcpv6-server counter accept
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iif != {{ internet_iface }} tcp dport @allow_tcp_in ct state new counter accept
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iif != {{ internet_iface }} udp dport @allow_udp_in ct state new counter accept
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iif {{ internet_iface }} drop
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pkttype != host drop
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}
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}
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