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New Member

ACL before (Router) or after(Multilayer Switch) Firewall

I have the following network topology (from outside to inside):

Router <=> Firewall <=> Multilayer Switch <=> L2 Switches <=> PC & Servers

One of my Servers is Web-server and there is a requirement to eliminate  the access to the Web-Site (which is resides to this Web-Server) to  specific range of public IP Addresses.

For instance my Web-Server  has the Private IP Address and  via static NAT at my firewall takes place the translation to one Public  IP Address

In order to implement the requirement I have two basic options:

1)Set ACL at Router to the appropriate physical Gigabit interface

In this instance I am using the internal gigabit interface towards my  Firewall. In order to construct the ACL I am using for the destination  IP Address the public IP ( In this case every packet from  the internet must be inspect by this ACL before enter to my local  network.

2)Set ACL at Multilayer Switch to the appropriate Vlan Interface.

In this instance I am using the corresponding Vlan interface (at the  same network of my Web servers). In order to create the ACL I utilize  for the destination Address the private IP Address ( as now  there has been executed the NAT translation. In this case the I  constraint the inspection only to a specific VLAN but also at the same  time many unwanted packets come into my local network  up to the  Mutlilayer Switch.

Which of these two methods could be assessed more ideal in terms of performance and security?

Everyone's tags (4)
New Member

ACL before (Router) or after(Multilayer Switch) Firewall

In my opinion the best way it to set the ACL at the Router or Firewall Outside interface.

if your objective it to restrict outside traffic from accessing your local network.



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