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PowerConnect B-Series FCX Configuration Guide
53-1002266-01
How hardware-based ACLs work
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How hardware-based ACLs work
When you bind an ACL to inbound traffic on an interface, the device programs the Layer 4 CAM with
the ACL. Permit and deny rules are programmed. Most ACL rules require one Layer 4 CAM entry.
However, ACL rules that match on more than one TCP or UDP application port may require several
CAM entries. The Layer 4 CAM entries for ACLs do not age out. They remain in the CAM until you
remove the ACL:
•
If a packet received on the interface matches an ACL rule in the Layer 4 CAM, the device
permits or denies the packet according to the ACL.
•
If a packet does not match an ACL rule, the packet is dropped, since the default action on an
interface that has ACLs is to deny the packet.
How fragmented packets are processed
The descriptions above apply to non-fragmented packets. The default processing of fragments by
hardware-based ACLs is as follows:
•
The first fragment of a packet is permitted or denied using the ACLs. The first fragment is
handled the same way as non-fragmented packets, since the first fragment contains the Layer
4 source and destination application port numbers. The device uses the Layer 4 CAM entry if
one is programmed, or applies the interface's ACL entries to the packet and permits or denies
the packet according to the first matching ACL.
•
For other fragments of the same packet, they are subject to a rule only if there is no Layer 4
information in the rule or in any preceding rules.
The fragments are forwarded even if the first fragment, which contains the Layer 4 information,
was denied. Generally, denying the first fragment of a packet is sufficient, since a transaction
cannot be completed without the entire packet.
For tighter control, you can configure the port to drop all packet fragments. Refer to
“Enabling strict
control of ACL filtering of fragmented packets”
on page 572.
Hardware aging of Layer 4 CAM entries
Rule-based ACLs use Layer 4 CAM entries. The device permanently programs rule-based ACLs into
the CAM. The entries never age out.
Configuration considerations
•
PowerConnect devices support inbound ACLs. Outbound ACL are not supported.
•
Hardware-based ACLs are supported on:
•
Gbps Ethernet ports
•
10 Gbps Ethernet ports
•
Trunk groups
•
Virtual routing interfaces
Содержание PowerConnect B-FCXs
Страница 1: ...53 1002266 01 18 March 2011 PowerConnect B Series FCX Configuration Guide ...
Страница 136: ...94 PowerConnect B Series FCX Configuration Guide 53 1002266 01 Viewing information about software licenses 4 ...
Страница 228: ...186 PowerConnect B Series FCX Configuration Guide 53 1002266 01 PowerConnect B Series FCX hitless stacking 5 ...
Страница 229: ...PowerConnect B Series FCX Configuration Guide 187 53 1002266 01 PowerConnect B Series FCX hitless stacking 5 ...
Страница 230: ...188 PowerConnect B Series FCX Configuration Guide 53 1002266 01 PowerConnect B Series FCX hitless stacking 5 ...
Страница 248: ...206 PowerConnect B Series FCX Configuration Guide 53 1002266 01 IPv6 management commands 7 ...
Страница 346: ...304 PowerConnect B Series FCX Configuration Guide 53 1002266 01 802 1s Multiple Spanning Tree Protocol 8 ...
Страница 374: ...332 PowerConnect B Series FCX Configuration Guide 53 1002266 01 Jumbo frame support 9 ...
Страница 424: ...382 PowerConnect B Series FCX Configuration Guide 53 1002266 01 Virtual Switch Redundancy Protocol VSRP 10 ...
Страница 568: ...526 PowerConnect B Series FCX Configuration Guide 53 1002266 01 CLI examples 14 ...
Страница 588: ...546 PowerConnect B Series FCX Configuration Guide 53 1002266 01 Sample application 15 ...
Страница 674: ...632 PowerConnect B Series FCX Configuration Guide 53 1002266 01 Enabling or disabling layer 2 switching 19 ...
Страница 684: ...642 PowerConnect B Series FCX Configuration Guide 53 1002266 01 VLAN based mirroring 20 ...
Страница 724: ...682 PowerConnect B Series FCX Configuration Guide 53 1002266 01 Reading CDP packets 23 ...
Страница 768: ...726 PowerConnect B Series FCX Configuration Guide 53 1002266 01 Clearing cached LLDP neighbor information 24 ...
Страница 930: ...888 PowerConnect B Series FCX Configuration Guide 53 1002266 01 26 ...
Страница 948: ...906 PowerConnect B Series FCX Configuration Guide 53 1002266 01 Configuring MLD snooping 27 ...
Страница 962: ...920 PowerConnect B Series FCX Configuration Guide 53 1002266 01 Displaying CPU utilization statistics 28 ...
Страница 1022: ...980 PowerConnect B Series FCX Configuration Guide 53 1002266 01 Displaying OSPF information 29 ...
Страница 1142: ...1100 PowerConnect B Series FCX Configuration Guide 53 1002266 01 Clearing diagnostic buffers 30 ...
Страница 1258: ...1216 PowerConnect B Series FCX Configuration Guide 53 1002266 01 Using Secure copy with SSH2 33 ...
Страница 1314: ...1272 PowerConnect B Series FCX Configuration Guide 53 1002266 01 Displaying port security information 35 ...
Страница 1348: ...1306 PowerConnect B Series FCX Configuration Guide 53 1002266 01 Example configurations 36 ...
Страница 1406: ...1364 PowerConnect B Series FCX Configuration Guide 53 1002266 01 IP source guard 39 ...
Страница 1422: ...1380 PowerConnect B Series FCX Configuration Guide 53 1002266 01 SNMP v3 Configuration examples 40 ...