Efficient Networks 107-0001-000 - Manual (Page 162)

Chapter 5: Ethernet Interface Commands Efficient Networks ® Router family
Command Line Interface Guide
Page 5-24 Efficient Networks
®
NOTE:
More than one -tcp option may be specified for the IP filter.
The syn, ack, and noflag settings work together as follows:
• Specify -tcp syn if the TCP SYN flag must be set.
• Specify -tcp ack if the TCP ACK flag must be set
• Specify -tcp noflag if neither the SYN flag nor the ACK flag can be set.
For example, for the IP filter to match the initiation of a TCP connection, specify -tcp
syn. The filter will match TCP packets that have the TCP SYN flag set but not the TCP
ACK flag set. For the filter to match the response to initiation of a TCP connection,
specify -tcp syn and -tcp ack. The filter will match only TCP packets with both the TCP
SYN and TCP ACK flags set.
The -tcp rst setting is independent of the others; if you specify -tcp rst for the filter, the
filter matches every TCP packet with the TCP RESET flag set, regardless of the other
flag settings. For example, for the filter to match packets for “established”
connections, you would specify both -tcp rst and -tcp ack so that the filter is applied to
every TCP packet that has either the RESET flag or the ACK flag set.
The following <parameter>s request additional filter options.
-dp <ICMP type> | <first dest port>[:<last dest port>]
The packet must have a destination port that matches the specified ICMP type or
that is within the specified port range. If only one port is specified, the packet must
have that destination port. If no destination port is specified, the filter matches any
destination port in the range 0:0xffff.
-tcp syn | ack | noflag | rst
If the IP packet is a TCP packet, the filter matches the packet only if the packet flag
settings are as specified. If no
-tcp option is specified for the filter, flag settings are
not checked.
-b
This option requests that this filter be compared twice with each packet. The first
time the source filter information is matched against the source information in the
IP packet and the destination filter information is matched against the destination
information in the IP packet. The second time the source filter information is
matched against the destination information in the IP packet and the destination fil-
ter information is matched against the source information in the IP packet.
-c <count of times rule used>
This option requests a counter for this filter. If specified, a count is kept of how
many IP packets have matched this filter since the router was rebooted. To see the
current count for a filter, use the eth ip filter list command. To clear a counter, use
the
eth ip filter clear command.
-ipsec <IPSec record name>
Use this option when the action specified is inipsec or outipsec. It specifies the IP-
Sec Security Association that uses the filter.