Digi TransPort WR31 User Manual page 696

Configure security settings
Firewall script rule fields
Firewall script rule fields are as follows:
[action]
The action to be performed. Acceptable values are block, pass, pass-ifup, dscp, vdscp, or
debug. These actions operate as follows:
block
Prevents a packet from being allowed through the firewall. When block is specified, an optional
field can be included that causes an ICMP packet to be returned to the interface from which that
packet was received. You can use blocking to confuse hackers by having different responses to
different packets or for fooling an attacker into thinking a service is not present on a network.
The syntax for specifying the return of an ICMP packet is:
"return-icmp" [icmp-type [icmp-code]]
where [icmp_type] is a decimal number representing the ICMP type, or one of the predefined
text codes listed in the following table:
ICMP type value
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Digi TransPort WR Routers User Guide
ICMP type
Unreach
Echo
Echorep
squench
redir
timex
paraprob
timest
timestrap
inforeq
inforep
maskreg
maskrep
routerad
routersol
Firewall
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