MicroNugget: What are SRX Security Flows?

In this video, Scott Morris covers JUNOS SRX security flows. When packets arrive, a router or security gateway has certain policies and tables that help decide what to do with those packets. This video helps explain the flow of lookups and decisions a device makes to maintain security.

Scott uses a flow chart to help demonstrate the JUNOS security model and what happens to packets entering a security gateway. First, they pass through the stateless filters and policers and they're checked to see if a session already exists for them. If not, a series of lookups is performed to determine what's to be done with them. This includes firewall policies, destination-NAT, routing, zones based on ingress/egress, routing policies, source-NAT, and application layer group configuration.

With the results of those lookups, a session is created. No policies have been applied at this point — that treatment requires a session. The session table is where the information is stored about what to apply to each packet: firewall options, basic TCP features, NAT features and ALG services. From there, stateless output filters and shapers can be applied, and the security process has run its course.

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[muralifayaz]

Superb video thanking you sir for this information

[wmurray]

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