Brocade FastIron Ethernet Switch Security Configuration Guide User Manual

Page 119

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The wildcard parameter specifies the portion of the source IP host address to match against. The
wildcard is in dotted-decimal notation (IP address format). It is a four-part value, where each part is 8
bits (one byte) separated by dots, and each bit is a one or a zero. Each part is a number ranging from 0
to 255, for example 0.0.0.255. Zeros in the mask mean the packet’s source address must match the
source-ip . Ones mean any value matches. For example, the source-ip and wildcard values
10.157.22.26 0.0.0.255 mean that all hosts in the Class C subnet 10.157.22.x match the policy.

If you prefer to specify the wildcard (mask value) in Classless Interdomain Routing (CIDR) format, you
can enter a forward slash after the IP address, then enter the number of significant bits in the mask. For
example, you can enter the CIDR equivalent of "10.157.22.26 0.0.0.255" as "10.157.22.26/24". The CLI
automatically converts the CIDR number into the appropriate ACL mask (where zeros instead of ones
are the significant bits) and changes the non-significant portion of the IP address into zeros. For
example, if you specify 10.157.22.26/24 or 10.157.22.26 0.0.0.255, then save the changes to the
startup-config file, the value appears as 10.157.22.0/24 (if you have enabled display of subnet lengths)
or 10.157.22.0 0.0.0.255 in the startup-config file.

If you enable the software to display IP subnet masks in CIDR format, the mask is saved in the file in "/
mask-bits " format. To enable the software to display the CIDR masks, enter the ip show-subnet-
length
command at the global CONFIG level of the CLI. You can use the CIDR format to configure the
ACL entry regardless of whether the software is configured to display the masks in CIDR format.

NOTE
If you use the CIDR format, the ACL entries appear in this format in the running-config and startup-
config files, but are shown with subnet mask in the display produced by the show ip access-list
command.

The destination-ip | hostname parameter specifies the destination IP host for the policy. If you want the
policy to match on all destination addresses, enter any .

The icmp-type | icmp-num parameter specifies the ICMP protocol type:

• This parameter applies only if you specified icmp as the ip-protocol value.
• If you use this parameter, the ACL entry is sent to the CPU for processing.
• If you do not specify a message type, the ACL applies to all types of ICMP messages.

The icmp-num parameter can be a value from 0 - 255.

The icmp-type parameter can have one of the following values, depending on the software version the
device is running:

• any-icmp-type
• echo
• echo-reply
• information-request
• log
• mask-reply
• mask-request
• parameter-problem
• redirect
• source-quench
• time-exceeded
• timestamp-reply
• timestamp-request
• traffic policy
• unreachable
• num

Rule-Based IP ACLs

FastIron Ethernet Switch Security Configuration Guide

119

53-1003088-03

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