WESM zl Management and Configuration Guide WT.01.28 and greater

7-19
Access Control Lists (ACLs)
Configuring ACLs
The ICMP Type and ICMP Code settings are based on the first 16 bits of the
32-bit ICMPv6 message packet, illustrated in Figure 7-7.
Figure 7-7. ICMPv6 Message Packet
In the ICMPv6 message packet:
– The ICMP type value is based on the first eight bits (bits 0 through 7).
ICMP type values from 0 through 127 are used for error messages, and
ICMP type values from 128 through 255 are used for information
messages.
– The ICMP code value is based on the second eight bits (bits 8
through 15). This value depends on the ICMP message type, and
specifies the type of packet with more granularity.
Table 7-5 lists common ICMP types and the corresponding ICMP codes.
Use this table to find the correct values for the packets that you want to
control, and then enter the values in the ICMP Type and ICMP Code fields
of the ICMP Options screen.
Click the OK button to return to the Add Rule screen and finish configuring
other filters.
Table 7-5. ICMP Types and Codes
ICMP
Typ e
Type Description ICMP
Code
Code Description
1 Destination Unreachable
message
0 No route to destination
1 Communication with destination
administratively prohibited
2 (Not assigned)
3 Address unreachable
4 Port unreachable
2 Packet Too Big message 0 Set to 0 by the sender and ignored by
the receiver