Users Guide

Layer 2 Switching Commands 281
Default Configuration
No ACLs are configured by default. An implicit deny all condition is added by
the system after the last MAC or IP/IPv6 access group if no route-map is
configured on the interface.
Command Mode
Ipv4-Access-List Configuration mode
User Guidelines
Administrators are cautioned to specify permit and deny rule matches as fully
as is possible in order to avoid false matches. Rules that specify an IP port
value should also specify the protocol (TCP or UDP) and relevant IP
addresses or subnets. In general, any rule that specifies matching on an upper
layer protocol field should also include matching constraints for lower layer
protocol fields. For example, a rule to match packets directed to the well-
known UDP port number 22 (SSH) should also include constraints on the IP
protocol field (UDP). IPv4 and IPv6 ACLs implicitly include the EtherType
in the match criteria. Below is a list of commonly used EtherTypes:
Ethertype Protocol
0x0800 Internet Protocol version 4 (IPv4)
0x0806 Address Resolution Protocol (ARP)
0x0842 Wake-on LAN Packet
0x8035 Reverse Address Resolution Protocol (RARP)
0x8100 VLAN tagged frame (IEEE 802.1Q)
0x86DD Internet Protocol version 6 (IPv6)
0x8808 MAC Control
0x8809 Slow Protocols (IEEE 802.3)
0x8870 Jumbo frames
0x888E EAP over LAN (EAPOL – IEEE 802.1x)
0x88CC Link Layer Discovery Protocol
0x8906 Fibre Channel over Ethernet
0x8914 FCoE Initialization Protocol