Traffic Management And Improved Network Performance; Security - HP ProCurve 6120G/XG Manual

Traffic Management and Improved
Network Performance
You can use ACLs to block unnecessary traffic caused by individual hosts,
workgroups, or subnets, and to block user access to subnets, devices, and
services. Answering the following questions can help you to design and
properly position ACLs for optimum network usage.
■ What are the logical points for minimizing unwanted traffic? In many
cases it makes sense to block unwanted traffic from the core of your
network by configuring ACLs to drop such traffic at or close to the
edge of the network. (The earlier in the network path you block
unwanted traffic, the greater the benefit for network performance.)
What traffic should you explicitly block? Depending on your network
■
size and the access requirements of individual hosts, this can involve
creating a large number of ACEs in a given ACL (or a large number of
ACLs), which increases the complexity of your solution and rapidly
consumes the resources.
What traffic can you implicitly block by taking advantage of the
■
implicit deny any to deny traffic that you have not explicitly permitted?
This can reduce the number of entries needed in an ACL and make
more economical use of switch resources.
■ What traffic should you permit? In some cases you will need to
explicitly identify permitted traffic. In other cases, depending on your
policies, you can insert a permit any (standard ACL) or permit ip any
any (extended ACL) entry at the end of an ACL. This means that all IP
traffic not specifically matched by earlier entries in the list will be
permitted.

Security

ACLs can enhance security by blocking inbound IP traffic carrying an unau­
thorized source IP address (SA). This can include:
■ Blocking access to or from subnets in your network
■ Blocking access to or from the internet
■ Blocking access to sensitive data storage or restricted equipment
IPv4 Access Control Lists (ACLs)

Traffic Management and Improved Network Performance

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