Administrator Guide

{deny | permit} udp {source mask | any | host ip-address}} [count [byte]] [order] [monitor
[session-id]] [fragments]
When you use the log keyword, the CP logs details about the packets that match. Depending on how many packets match the log entry
and at what rate, the CP may become busy as it has to log these packets’ details.
The following example shows an extended IP ACL in which the software assigned the sequence numbers. The lters were assigned
sequence numbers based on the order in which they were congured (for example, the rst lter was given the lowest sequence number).
The show config command in IP ACCESS LIST mode displays the two lters with the sequence numbers 5 and 10.
Example of Viewing Filter Sequence for a Specied Extended ACL
Dell(config-ext-nacl)#deny tcp host 123.55.34.0 any
Dell(config-ext-nacl)#permit udp 154.44.123.34 0.0.255.255 host 34.6.0.0 monitor 199
Dell(config-ext-nacl)#show config
!
ip access-list extended nimule
seq 5 deny tcp host 123.55.34.0 any
seq 10 permit udp 154.44.0.0 0.0.255.255 host 34.6.0.0 monitor 199
Dell(config-ext-nacl)#
To view all congured IP ACLs and the number of packets processed through the ACL, use the show ip accounting access-list
command in EXEC Privilege mode, as shown in the rst example in Congure a Standard IP ACL.
Established Flag
To obtain the functionality of est, use the following ACLs.
• permit tcp any any rst
• permit tcp any any ack
Congure Layer 2 and Layer 3 ACLs
You can congure both Layer 2 and Layer 3 ACLs on an interface in Layer 2 mode.
If both L2 and L3 ACLs are applied to an interface, the following rules apply:
• When Dell Networking OS routes the packets, only the L3 ACL governs them because they are not ltered against an L2 ACL.
• When Dell Networking OS switches the packets, rst the L3 ACL lters them, then the L2 ACL lters them.
• When Dell Networking OS switches the packets, the egress L3 ACL does not lter the packet.
For the following features, if you enable counters on rules that have already been congured and a new rule is either inserted or prepended,
all the existing counters are reset:
• L2 ingress access list
• L3 egress access list
• L2 egress access list
• L3 ingress access list
If a rule is simply appended, existing counters are not aected.
Table 7. L2 and L3 Filtering on Switched Packets
L2 ACL Interfaces Behavior L3 ACL Interfaces Behavior Decision on Targeted Trac
Deny Deny L3 ACL denies.
Deny Permit L3 ACL permits.
Permit Deny L3 ACL denies.
Permit Permit L3 ACL permits.
Access Control Lists (ACLs) 117