User Manual

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2.
Interface
name
eth0 tap0
Specifies LAN interface name
7.6 Firewall
In this section we will look over the various firewall features that come with RUT230.
7.6.1 General Settings
The router’s firewall is a standard Linux iptables package, which uses routing chains and policies to facilitate control
over inbound and outbound traffic.
Field Name
Sample value
Explanation
1.
Drop Invalid
packets
Checked/Unchecked
A “Drop” action is performed on a packet that is determined to be invalid
2.
Input
Reject/Drop/Accept
DEFAULT* action that is to be performed for packets that pass through the
Input chain.
3.
Output
Reject/Drop/Accept
DEFAULT* action that is to be performed for packets that pass through the
Output chain.
4.
Forward
Reject/Drop/Accept
DEFAULT* action that is to be performed for packets that pass through the
Forward chain.
*DEFAULT: When a packet goes through a firewall chain it is matched against all the rules for that specific chain. If
no rule matches said packet, an according Action (either Drop or Reject or Accept) is performed.
Accept – Packet gets to continue down the next chain.
Drop – Packet is stopped and deleted.
Reject – Packet is stopped, deleted and, differently from Drop, an ICMP packet containing a message of rejection is
sent to the source of the dropped packet.