access-list ip

Syntax

Syntax to create an IPv4 ACL and enter its context. Plus syntax to remove an ACL:

access-list ip <ACL-NAME>

no access-list ip <ACL-NAME>

Syntax (within the ACL context) for creating or removing ACEs for protocols ah, gre, esp, igmp, ospf, pim (ip is available as an alias for any):

  [<SEQUENCE-NUMBER>]
  {permit|deny}
  {any|ip|ah|gre|esp|igmp|ospf|pim|<IP-PROTOCOL-NUM>}
  {any|<SRC-IP-ADDRESS>[/{<PREFIX-LENGTH>|<SUBNET-MASK>}]|<ADDRESS-GROUP>}
  {any|<DST-IP-ADDRESS>[/{<PREFIX-LENGTH>|<SUBNET-MASK>}]|<ADDRESS-GROUP>}
  [dscp <DSCP-SPECIFIER>] [ecn <ECN-VALUE>] [ip-precedence <IP-PRECEDENCE-VALUE>]
  [tos <TOS-VALUE>] [fragment] [vlan <VLAN-ID>] [ttl <TTL-VALUE>] [count] [log]

  no <SEQUENCE-NUMBER>

Syntax (within the ACL context) for creating or removing ACEs for protocols sctp, tcp, udp:

  [<SEQUENCE-NUMBER>]
  {permit|deny}
  {sctp|tcp|udp}
  {any|<SRC-IP-ADDRESS>[/{<PREFIX-LENGTH>|<SUBNET-MASK>}]|<ADDRESS-GROUP>}
  [{eq|gt|lt} <PORT>|range <MIN-PORT> <MAX-PORT>|group <PORT-GROUP>]
  {any|<DST-IP-ADDRESS>[/{<PREFIX-LENGTH>|<SUBNET-MASK>}]|<ADDRESS-GROUP>}
  [{eq|gt|lt} <PORT>|range <MIN-PORT> <MAX-PORT>|group <PORT-GROUP>]
  [urg] [ack] [psh] [rst] [syn] [fin] [established]
  [dscp <DSCP-SPECIFIER>] [ecn <ECN-VALUE>]  [ip-precedence <IP-PRECEDENCE-VALUE>]
  [tos <TOS-VALUE>]  [fragment] [vlan <VLAN-ID>] [ttl <TTL-VALUE>] [count] [log]

  no <SEQUENCE-NUMBER>

Syntax (within the ACL context) for creating or removing ACEs for protocol icmp:

  [<SEQUENCE-NUMBER>]
  {permit|deny}
  {icmp}
  {any|<SRC-IP-ADDRESS>[/{<PREFIX-LENGTH>|<SUBNET-MASK>}]|<ADDRESS-GROUP>}
  {any|<DST-IP-ADDRESS>[/{<PREFIX-LENGTH>|<SUBNET-MASK>}]|<ADDRESS-GROUP>}
  [icmp-type {echo|echo-reply|<ICMP-TYPE-VALUE>}] [icmp-code <ICMP-CODE-VALUE>]
  [dscp <DSCP-SPECIFIER>] [ecn <ECN-VALUE>]  [ip-precedence <IP-PRECEDENCE-VALUE>]
  [tos <TOS-VALUE>] [fragment] [vlan <VLAN-ID>] [ttl <TTL-VALUE>] [count] [log]

  no <SEQUENCE-NUMBER>

Syntax (within the ACL context) for ACE comments:

  [<SEQUENCE-NUMBER>] comment <TEXT-STRING>

  no <SEQUENCE-NUMBER> comment

Description

Creates an IPv4 Access Control List (ACL) comprised of one or more Access Control Entries (ACEs) ordered and prioritized by sequence number. The lowest sequence number is the highest prioritized ACE.

The no form of this command deletes the entire ACL, or deletes an ACE identified by sequence number, or deletes only the comment from the ACE identified by sequence number.

Command context

config

The access-list ip <ACL-NAME> command takes you into the named ACL context where you enter the ACEs.

Parameters

<ACL-NAME>

Specifies the name of this ACL.

<SEQUENCE-NUMBER>

Specifies a sequence number for the ACE. Range: 1 to 4294967295.

{permit|deny}

Specifies whether to permit or deny traffic matching this ACE.

<IP-PROTOCOL-NUM>

Specifies the protocol as its Internet Protocol number. For example, 2 corresponds to the IGMP protocol. Range: 0 to 255.

{any|<SRC-IP-ADDRESS>[/{<PREFIX-LENGTH>|<SUBNET-MASK>}]|<ADDRESS-GROUP>}
Specifies the source IPv4 address.
  • any - specifies any source IPv4 address.

  • <SRC-IP-ADDRESS> - specifies the source IPv4 host address.

    • <PREFIX-LENGTH> - specifies the address bits to mask (CIDR subnet mask notation). Range: 1 to 32.

    • <SUBNET-MASK> - specifies the address bits to mask (dotted decimal notation).

  • <ADDRESS-GROUP> - specifies an IPv4 address group defined with object-group ip address.

{any|<DST-IP-ADDRESS>[/{<PREFIX-LENGTH>|<SUBNET-MASK>}]|<ADDRESS-GROUP>}
Specifies the destination IPv4 address.
  • any - specifies any destination IPv4 address.

  • <DST-IP-ADDRESS> - specifies the destination IPv4 host address.

    • <PREFIX-LENGTH> - specifies the address bits to mask (CIDR subnet mask notation). Range: 1 to 32.

    • <SUBNET-MASK> - specifies the address bits to mask (dotted decimal notation).

  • <ADDRESS-GROUP> - specifies an IPv4 address group that you defined earlier with object-group ip address.

[{eq|gt|lt} <PORT>|range <MIN-PORT> <MAX-PORT>|group <PORT-GROUP>]
Specifies the port, port range, or port group. Port numbers are in the range of 0 to 65535.
  • eq <PORT> - specifies the Layer 4 port.

  • gt <PORT> - specifies any Layer 4 port greater than the indicated port.

  • lt <PORT> - specifies any Layer 4 port less than the indicated port.

  • range <MIN-PORT> <MAX-PORT> - specifies the Layer 4 port range.

  • group <PORT-GROUP> - specifies the Layer 4 port group that you defined earlier with object-group port.

NOTE:

Upon application of the ACL, ACEs with L4 port ranges may consume more than one hardware entry.

urg

Specifies matching on the TCP Flag: Urgent.

ack

Specifies matching on the TCP Flag: Acknowledgment.

psh

Specifies matching on the TCP Flag: Push buffered data to receiving application.

rst

Specifies matching on the TCP Flag: Reset the connection.

syn

Specifies matching on the TCP Flag: Synchronize sequence numbers.

fin

Specifies matching on the TCP Flag: Finish connection.

established

Specifies matching on the TCP Flag: Established connection.

[icmp-type {echo|echo-reply|<ICMP-TYPE-VALUE>}]
Specifies the ICMP type.
  • echo - specifies an ICMP echo request packet.

  • echo-reply - specifies an ICMP echo reply packet.

  • <ICMP-TYPE-VALUE> - specifies an ICMP type value. Range: 0 to 255.

[icmp-code <ICMP-CODE-VALUE>]

Specifies the ICMP code value. Range: 0 to 255.

dscp <DSCP-SPECIFIER>

Specifies the Differentiated Services Code Point (DSCP), either a numeric <DSCP-VALUE> (0 to 63) or one of these keywords:

  • AF11 - DSCP 10 (Assured Forwarding Class 1, low drop probability)

  • AF12 - DSCP 12 (Assured Forwarding Class 1, medium drop probability)

  • AF13 - DSCP 14 (Assured Forwarding Class 1, high drop probability)

  • AF21 - DSCP 18 (Assured Forwarding Class 2, low drop probability)

  • AF22 - DSCP 20 (Assured Forwarding Class 2, medium drop probability)

  • AF23 - DSCP 22 (Assured Forwarding Class 2, high drop probability)

  • AF31 - DSCP 26 (Assured Forwarding Class 3, low drop probability)

  • AF32 - DSCP 28 (Assured Forwarding Class 3, medium drop probability)

  • AF33 - DSCP 30 (Assured Forwarding Class 3, high drop probability)

  • AF41 - DSCP 34 (Assured Forwarding Class 4, low drop probability)

  • AF42 - DSCP 36 (Assured Forwarding Class 4, medium drop probability)

  • AF43 - DSCP 38 (Assured Forwarding Class 4, high drop probability)

  • CS0 - DSCP 0 (Class Selector 0: Default)

  • CS1 - DSCP 8 (Class Selector 1: Scavenger)

  • CS2 - DSCP 16 (Class Selector 2: OAM)

  • CS3 - DSCP 24 (Class Selector 3: Signaling)

  • CS4 - DSCP 32 (Class Selector 4: Real time)

  • CS5 - DSCP 40 (Class Selector 5: Broadcast video)

  • CS6 - DSCP 48 (Class Selector 6: Network control)

  • CS7 - DSCP 56 (Class Selector 7)

  • EF - DSCP 46 (Expedited Forwarding)

ecn <ECN-VALUE>

Specifies an Explicit Congestion Notification value. Range: 0 to 3.

ip-precedence <IP-PRECEDENCE-VALUE>

Specifies an IP precedence value. Range: 0 to 7.

tos <TOS-VALUE>

Specifies the Type of Service value. Range: 0 to 31.

fragment

Specifies a fragment packet.

vlan <VLAN-ID>

Specifies VLAN tag to match on. 802.1Q VLAN ID.

NOTE:

This parameter cannot be used in any ACL that will be applied to a VLAN.

ttl <TTL-VALUE>

Specifies a time-to-live (hop limit) value. Range: 0 to 255. Not supported for ACLs.

count

Keeps the hit counts of the number of packets matching this ACE.

log

Keeps a log of the number of packets matching this ACE. Works with both permit and deny actions. Works with ACLs applied on ingress or egress, except for control plane.

[<SEQUENCE-NUMBER>] comment <TEXT-STRING>

Adds a comment to an ACE. The no form removes only the comment from the ACE.

Authority

Administrators or local user group members with execution rights for this command.

Usage

  • If the <IP-PROTOCOL-NUM> parameter is used instead of a protocol name, ensure that any needed ACE-definition parameters specific to the selected protocol are also provided.

  • When using multiple ACL types (IPv4, IPv6, or MAC) with logging on the same interface, the first packet that matches an ACE with log option is logged. Until the log-timer wait-period is over, any packets matching other ACL types do not create a log. At the end of the wait-period, the switch creates a summary log for all the ACLs that were matched, regardless of type.

Examples

Creating an IPv4 ACL with four entries:

switch(config)# access-list ip MY_IP_ACL
switch(config-acl-ip)# 10 permit udp any 172.16.1.0/24
switch(config-acl-ip)# 20 permit tcp 172.16.2.0/16 gt 1023 any
switch(config-acl-ip)# 30 permit tcp 172.26.1.0/24 any syn ack dscp 10
switch(config-acl-ip)# 40 deny any any any count
switch(config-acl-ip)# exit

switch(config)# show access-list
Type       Name
  Sequence Comment
           Action                          L3 Protocol
           Source IP Address               Source L4 Port(s)
           Destination IP Address          Destination L4 Port(s)
           Additional Parameters
-------------------------------------------------------------------------------
IPv4       MY_IP_ACL
        10 permit                          udp
           any
           172.16.1.0/255.255.255.0
        20 permit                          tcp
           172.16.2.0/255.255.0.0           >  1023
           any
        30 permit                          tcp
           172.26.1.0/255.255.255.0
           any
           dscp: AF11
           ack
           syn
        40 deny                            any
           any
           any
           Hit-counts: enabled

Adding a comment to an existing IPv4 ACE:

switch(config)# access-list ip MY_IP_ACL
switch(config-acl-ip)# 20 comment Permit all TCP ephemeral ports  
switch(config-acl-ip)# exit

switch(config)# show access-list
Type       Name
  Sequence Comment
           Action                          L3 Protocol
           Source IP Address               Source L4 Port(s)
           Destination IP Address          Destination L4 Port(s)
           Additional Parameters
-------------------------------------------------------------------------------
IPv4       MY_IP_ACL
        10 permit                          udp
           any
           172.16.1.0/255.255.255.0
        20 Permit all TCP ephemeral ports
           permit                          tcp
           172.16.2.0/255.255.0.0           >  1023
           any
        30 permit                          tcp
           172.26.1.0/255.255.255.0
           any
           dscp: AF11
           ack
           syn
        40 deny                            any
           any
           any
           Hit-counts: enabled

Removing a comment from an existing IPv4 ACE:

switch(config)# access-list ip MY_IP_ACL
switch(config-acl-ip)# no 20 comment
switch(config-acl-ip)# exit

switch(config)# show access-list
Type       Name
  Sequence Comment
           Action                          L3 Protocol
           Source IP Address               Source L4 Port(s)
           Destination IP Address          Destination L4 Port(s)
           Additional Parameters
-------------------------------------------------------------------------------
IPv4       MY_IP_ACL
        10 permit                          udp
           any
           172.16.1.0/255.255.255.0
        20 permit                          tcp
           172.16.2.0/255.255.0.0           >  1023
           any
        30 permit                          tcp
           172.26.1.0/255.255.255.0
           any
           dscp: AF11
           ack
           syn
        40 deny                            any
           any
           any
           Hit-counts: enabled

Adding an ACE (insert line 25) to an existing IPv4 ACL:

switch(config)# access-list ip MY_IP_ACL
switch(config-acl-ip)# 25 permit icmp 172.16.2.0/16 any
switch(config-acl-ip)# exit

switch(config)# show access-list
Type       Name
  Sequence Comment
           Action                          L3 Protocol
           Source IP Address               Source L4 Port(s)
           Destination IP Address          Destination L4 Port(s)
           Additional Parameters
-------------------------------------------------------------------------------
IPv4       MY_IP_ACL
        10 permit                          udp
           any
           172.16.1.0/255.255.255.0
        20 permit                          tcp
           172.16.2.0/255.255.0.0           >  1023
           any
        25 permit                          icmp
           172.16.2.0/255.255.0.0 any
        30 permit                          tcp
           172.26.1.0/255.255.255.0
           any
           dscp: AF11
           ack
           syn
        40 deny                            any
           any
           any
           Hit-counts: enabled

Replacing an ACE in an existing IPv4 ACL:

switch(config)# access-list ip MY_IP_ACL
switch(config-acl-ip)# 25 permit icmp 172.17.1.0/16 any
switch(config-acl-ip)# exit

switch(config)# show access-list
Type       Name
  Sequence Comment
           Action                          L3 Protocol
           Source IP Address               Source L4 Port(s)
           Destination IP Address          Destination L4 Port(s)
           Additional Parameters
-------------------------------------------------------------------------------
IPv4       MY_IP_ACL
        10 permit                          udp
           any
           172.16.1.0/255.255.255.0
        20 permit                          tcp
           172.16.2.0/255.255.0.0           >  1023
           any
        25 permit                          icmp
           172.17.1.0/255.255.0.0
        30 permit                          tcp
           172.26.1.0/255.255.255.0
           any
           dscp: AF11
           ack
           syn
        40 deny                            any
           any
           any
           Hit-counts: enabled

Removing an ACE from an IPv4 ACL:

switch(config)# access-list ip MY_IP_ACL
switch(config-acl-ip)# no 25
switch(config-acl-ip)# exit

switch(config)# show access-list
Type       Name
  Sequence Comment
           Action                          L3 Protocol
           Source IP Address               Source L4 Port(s)
           Destination IP Address          Destination L4 Port(s)
           Additional Parameters
-------------------------------------------------------------------------------
IPv4       MY_IP_ACL
        10 permit                          udp
           any
           172.16.1.0/255.255.255.0
        20 permit                          tcp
           172.16.2.0/255.255.0.0           >  1023
           any
        30 permit                          tcp
           172.26.1.0/255.255.255.0
           any
           dscp: AF11
           ack
           syn
        40 deny                            any
           any
           any
           Hit-counts: enabled

Copy an IPv4 ACL:

switch(config)# access-list ip MY_IP_ACL copy MY_IP_ACL2
switch(config)# show access-list 
Type       Name                                              
  Sequence Comment                                           
           Action                          L3 Protocol       
           Source IP Address               Source L4 Port(s) 
           Destination IP Address          Destination L4 Port(s)
           Additional Parameters                             
-------------------------------------------------------------------------------
IPv4       MY_IP_ACL
        10 
           permit                          udp 
           any                             
           172.16.1.0/255.255.255.0        
        20 
           permit                          tcp 
           172.16.2.0/255.255.0.0           >  1023
           any                             
        30 
           permit                          tcp 
           172.26.1.0/255.255.255.0        
           any                             
           dscp: AF11 
           ack 
           syn 
        40 
           deny                            any  
           any                             
           any                             
           Hit-counts: enabled 
-------------------------------------------------------------------------------
IPv4       MY_IP_ACL2
        10 
           permit                          udp 
           any                             
           172.16.1.0/255.255.255.0        
        20 
           permit                          tcp 
           172.16.2.0/255.255.0.0           >  1023
           any                             
        30 
           permit                          tcp 
           172.26.1.0/255.255.255.0        
           any                             
           dscp: AF11 
           ack 
           syn 
        40 
           deny                            any  
           any                             
           any                             
           Hit-counts: enabled 

Removing an IPv4 ACL:

switch(config)# no access-list ip MY_IP_ACL

switch(config)# show access-list
Type       Name
  Sequence Comment
           Action                          L3 Protocol
           Source IP Address               Source L4 Port(s)
           Destination IP Address          Destination L4 Port(s)
           Additional Parameters
-------------------------------------------------------------------------------
IPv4       MY_IP_ACL2
         1 permit                          udp
           any
           172.16.1.0/255.255.255.0
         2 permit                          tcp
           172.16.2.0/255.255.0.0           >  1023
           any
         3 permit                          tcp
           172.26.1.0/255.255.255.0
           any
           dscp: AF11
           ack
           syn
         4 deny                            any
           any
           any
           Hit-counts: enabled