1.1 VIRTUAL PRIVATE NETWORK:
A VPN is a method to connect the office network (for example Private network) from the client systems (for example home Laptop) via public network (for example an Internet). A VPN tunnelling will have the advantages of dial-up connection to a dial-up server, because of the flexibility of an Internet connection and also the ease access of an Internet connection. By using an Internet connection the client can connect to the server or the resource in all over the world, like accessing the office desktop from home through an Internet connection. The computer and the office desktop can communicate at full Internet speed or very high speed if you have an Internet connection as cable or digital subscriber line (DSL). This type of connection works very fast …show more content…
Example of Rule on a Listed Tree-Rule Firewall
For example, Rule-3 in Table1 is a shadowed rule because any packet that matches this rule has already matched Rule-1 in order of precedence.
1.3.2. REDUNDANT RULE:
If more than one rule can do the same action in the set of rules is called redundant rule, otherwise one rule is redundant to another rule with the same action. For example, Rule-8 in Table 1 is redundant to Rule-9. The firewall policy won’t change while removing a redundant rule. It will waste the firewall processing time and it leads to speed problem and also it require lot of memory to store the redundant rule. Without any change in the firewall policy, we can able to delete the redundant rules which are not necessary to check.
1.3.3. SWAPPING THE RULE POSITION:
In Listed-Rule firewall if two rules have different action then swapping the position of that rule can cause policy changes on the firewall and both of them can be matched with the same packet.
For example, swapping between Rule-7 and Rule-8 (see Table 1) will change the action on the packet (with Source IP = 172.3.3.9, Destination IP = 20.3.3.9, Destination Port = 80) from being accepted to being