Access Control List Commands
4-93
4
Command Usage
• A mask can only be used by all ingress ACLs or all egress ACLs.
• The precedence of the ACL rules applied to a packet is not determined by
order of the rules, but instead by the order of the masks; i.e., the first mask
that matches a rule will determine the rule that is applied to a packet.
• You must configure a mask for an ACL rule before you can bind it to a port or
set the queue or frame priorities associated with the rule.
Example
Related Commands
mask (IP ACL) (4-93)
ip access-group (4-97)
mask (IP ACL)
This command defines a mask for IP ACLs. This mask defines the fields to check in
the IP header. Use the no form to remove a mask.
Syntax
[no]mask [protocol]
{any | host | source-bitmask}
{any | host | destination-bitmask}
[precedence] [tos] [dscp]
[source-port [port-bitmask]] [destination-port [port-bitmask]]
[control-flag [flag-bitmask]]
•protocol – Check the protocol field.
•any – Any address will be matched.
•host – The address must be for a host device, not a subnetwork.
•source-bitmask – Source address of rule must match this bitmask.
• destination-bitmask – Destination address of rule must match this bitmask.
•precedence – Check the IP precedence field.
•tos – Check the TOS field.
•dscp – Check the DSCP field.
•source-port – Check the protocol source port field.
•destination-port – Check the protocol destination port field.
• port-bitmask – Protocol port of rule must match this bitmask.
(Range: 0-65535)
•control-flag – Check the field for control flags.
•flag-bitmask – Control flags of rule must match this bitmask. (Range: 0-63)
Default Setting
None
Console(config)#access-list ip mask-precedence in
Console(config-ip-mask-acl)#