CBAC (Context Base Access Control) is both a stateful and an application firewall that is it can filter traffic from network layer to Application Layer.
Context Base Access Control (CBAC) is a firewall that can filter traffic at network layer (source and destination IPs), Control Layer (source and destination ports, TCP and UDP sessions), Session Layer and Application Layer (protocols for special applications and multi-channel applications like FTP). It can also examine services like DNS, SMTP and other Application layer services.
As compared to reflexive ACL stateful filtering method CBAC is more advance stateful firewall because along with monitoring ACK,SYN, FIN, RST, source & destination IPs and Portts it can also inspect and monitor
TCP connections and sessions,UDP connections and Sessions, DNS queries and replies, Applications that relies on Multiple connections (tftp, ftp, multimedia) and Embedded services (NAT, PAT).
CBAC is a legacy Firewall and its very rarely used nowadays because a more advance version of stateful firewalls are available known as zone base firewalls and ASAs.
Configuration
Implementation of CBAC requires 2 steps
In first step the incoming traffic from outside is blocked using an inbound extended ACL
In 2nd step we define the protocol and services to be inspected
Step 1: Filtering Incoming Traffic
config t
ip access-list extended DENY
deny ip any any log
exit
interface fa 0/1
ip access-group DENY in
exit
Step 2: (Defining and Applying Inspection Method)
ip inspect name REMEBER tcp
ip inspect name REMEMBER udp
ip inspect name REMEMBER icmp
interface fa 0/1
ip inspect REMEMBER out
exit
with Applying these two steps your CBAC is up and running.
Using Zone Base Firewall
Using ASA (Adaptive Security Appliance)
Using Reflexive ACL
Context Base Access Control (CBAC) is a firewall that can filter traffic at network layer (source and destination IPs), Control Layer (source and destination ports, TCP and UDP sessions), Session Layer and Application Layer (protocols for special applications and multi-channel applications like FTP). It can also examine services like DNS, SMTP and other Application layer services.
As compared to reflexive ACL stateful filtering method CBAC is more advance stateful firewall because along with monitoring ACK,SYN, FIN, RST, source & destination IPs and Portts it can also inspect and monitor
TCP connections and sessions,UDP connections and Sessions, DNS queries and replies, Applications that relies on Multiple connections (tftp, ftp, multimedia) and Embedded services (NAT, PAT).
CBAC is a legacy Firewall and its very rarely used nowadays because a more advance version of stateful firewalls are available known as zone base firewalls and ASAs.
Configuration
Implementation of CBAC requires 2 steps
In first step the incoming traffic from outside is blocked using an inbound extended ACL
In 2nd step we define the protocol and services to be inspected
Step 1: Filtering Incoming Traffic
config t
ip access-list extended DENY
deny ip any any log
exit
interface fa 0/1
ip access-group DENY in
exit
Step 2: (Defining and Applying Inspection Method)
ip inspect name REMEBER tcp
ip inspect name REMEMBER udp
ip inspect name REMEMBER icmp
interface fa 0/1
ip inspect REMEMBER out
exit
with Applying these two steps your CBAC is up and running.
Using Zone Base Firewall
Using ASA (Adaptive Security Appliance)
Using Reflexive ACL
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