3com OfficeConnect Remote 812 Manual De Usuario

Creating Filters Using Command Line Interface

6-51

Generic Filter Rule

The syntax for generic filters is slightly different than that for other filters:

<line #> <verb> GENERIC => ORIGIN = <FRAME > DATA>/OFFSET = <# of bytes>/
LENGTH = <# of bytes>/MASK = < 0x Mask>/VALUE = <0x value>

ORIGIN - The location in the packet to start the offset count. This location can
be at byte 0 (FRAME) or at the start of the protocol data (DATA).

OFFSET - The number of bytes from the origin to skip before comparing the
value to the packet contents.

LENGTH - The number of bytes in the packet to compare to the value.

MASK - The mask to logically "and" with the packet contents before
comparing with the value (hex).

VALUE - The value (hex) to compare to the packet contents.

For example, a generic bridge filter to prevent all IP packets from being bridged is:

BR-ETH:
1 reject generic=>origin=frame/offset=12/length=2/mask=0xFFFF/value=0x0800;

Applying the Rules

Using CLI

The sections that follow provide detailed information and examples for creating
specific filters based on protocol.

Table 6-6 Protocol Keywords

Protocol
Section

Keyword

Operators

Description and Value Range

src-addr
dst-addr
tcp-src-port
tcp-dst-port
udp-src-port
udp-dst-port
protocol
generic

=, !=
=, !=
all
all
all
all
=, !=
=

Source IP Address (ddd.ddd.ddd.ddd/mask)
Destination IP Address (ddd.ddd.ddd.ddd/mask)
TCP source port (1 - 65535)
TCP destination port (1 - 65535)
UDP source port (1-65535)
UDP destination port (1-65535)
IP protocol (UDP, TCP, ICMP)
Generic filter

IP-RIP

network

=, !=

IP network number (ddd.ddd.ddd.ddd/mask)

IPX

src-net
dst-net
src-host
dst-host
src-socket
dst-socket
generic

=, !=
=, !=
=, !=
=, !=
all
all
=

Source IPX network (xx-xx-xx-xx)
Destination IPX network (xx-xx-xx-xx)
Source IPX host node address (xx-xx-xx-xx-xx-xx)
Destination IPX host node address (xx-xx-xx-xx-xx-xx)
Source IPX socket (0x1 - 0xFFFF)
Destination IPX socket (0x1 - 0xFFFF)
Generic Filter

IPX-RIP

network

=, !=

IPX network (xx-xx-xx-xx)

IPX-SAP

network
node
server
service-type
socket

=, !=
=, !=
=, !=
=, !=
all

IPX network (xx-xx-xx-xx)
IPX node (xx-xx-xx-xx-xx-xx)
Server name (character string to 32 characters)
Service type (0x0 - 0xFFFF)
Socket (0x1 - 0xFFFF)

BR-ETH

src-addr
dst-addr
generic

=, !=
=, !=
=

Source MAC address (xx-xx-xx-xx-xx-xx)
Destination MAC address (xx-xx-xx-xx-xx-xx)
Generic filter