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26 Cyclades ACS 5000 Advanced Console Server Command Reference Guide
UDP extensions
These extensions are loaded if the protocol udp is specified or -m udp is specified. It provides the
following options.
ICMP extension
This extension is loaded if the protocol icmp is specified or -m icmp is specified. It provides the
following option.
NOTE: For IPv6 configurations, the icmpv6 protocol is used.
[!] --syn Only match TCP packets with the SYN bit set and the ACK and FIN bits
cleared. Such packets are used to request TCP connection initiation; for
example, blocking such packets coming in an interface prevents
incoming TCP connections, but outgoing TCP connections are
unaffected. It is equivalent to - -tcp-flags SYN,RST,ACK SYN.
If the ! flag precedes the - -syn, the sense of the option is inverted.
--tcp-option [!] number Match if TCP option is set.
Table 2.12: UDP Extensions
UDP extension Description
--source-port [!] [port[:port]] Source port or port range specification. See the description of the - -
source-port option of the TCP extension for details.
--destination-port [!] [port[:port]] Destination port or port range specification. See the description of the - -
destination-port option of the TCP extension for details.
Table 2.13: ICMP Extensions
ICMP extension Description
--icmp-type [!] typename This allows specification of the ICMP type, which may be a numeric ICMP
type, or one of the ICMP type names shown by the command
iptables p icmp -h
Table 2.11: TCP Extensions (Continued)
TCP extension Description