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374 PowerConnect B-Series TI24X Configuration Guide
53-1002269-02
Configuring extended named ACLs
13
The first entry in this ACL denies TCP traffic from the 209.157.21.x network to the 209.157.22.x
network.
The second entry denies all FTP traffic from the 209.157.21.x network to the 209.157.22.x
network.
The third entry denies TCP traffic from the 209.157.21.x network to the 209.157.22.x network, if
the TCP port number of the traffic is less than the well-known TCP port number for Telnet (23), and
if the TCP port is not equal to 5. Thus, TCP packets whose TCP port numbers are 5 or are greater
than 23 are allowed.
The fourth entry denies UDP packets from any source to the 209.157.22.x network, if the UDP port
number from the source network is 5 or 6 and the destination UDP port is 7 or 8.
The fifth entry permits all packets that are not explicitly denied by the other entries. Without this
entry, the ACL would deny all incoming or outgoing IP traffic on the ports to which you assign the
ACL.
The following commands apply ACL 103 to the incoming traffic on ports 1 and 2.
Configuring extended named ACLs
The commands for configuring named ACL entries are different from the commands for configuring
numbered ACL entries. The command to configure a numbered ACL is access-list. The command
for configuring a named ACL is ip access-list. In addition, when you configure a numbered ACL
entry, you specify all the command parameters on the same command. When you configure a
named ACL, you specify the ACL type (standard or extended) and the ACL number with one
command, which places you in the configuration level for that ACL. Once you enter the
configuration level for the ACL, the command syntax is the same as the syntax for numbered ACLs.
Extended ACLs let you permit or deny packets based on the following information:
• IP protocol
• Source IP address or host name
• Destination IP address or host name
• Source TCP or UDP port (if the IP protocol is TCP or UDP)
• Destination TCP or UDP port (if the IP protocol is TCP or UDP)