MPLS VPN Security

C H A P T E R

5

Security Recommendations

In this chapter, we recommend security measures for every router and progress to customer

edge, core infrastructure, and provider edge security mechanisms. The reader will find a full

provider edge configuration example in Appendix A with a clarification of key security

explanations.

In any network, security considerations devolve into essentially two areas of focus, this

first area being compromises that can be either accidental or deliberate. Accidental

compromises can occur as a result of misconfigurations or by anticipated changes in the

network. Alternatively, compromises can be deliberate, such as attacks by some miscreant

entity determined to cause havoc. In either case, the risk vectors are either external, such

as issues driven by events external to the network in question, or internal, such as problems

that are sourced from within the network itself.

The methods used to accomplish the compromises are the second area of focus. Most

security-related problems fall into the categories of Denial of Service (DoS) or intrusion

in any network. Security considerations devolve into essentially two sets of two types of

issues. Compromises are either of the following:

• Accidental—Problems that occur due to misconfigurations or anticipated changes in

the network

• Deliberate—Attacks by some entity bent on causing havoc

The risk factors of these compromises are either external (issues driven by events external

to the network in question) or internal (problems sourced from within the network itself).

Additionally, most security-related problems fall into two categories:

• Denial of Service (DoS)—These events may be intentional or accidental.

• Reconnaisance—These issues by definition are intentional.

It is essential to harden the network components and the entire system to minimize the

likelihood of any of these scenarios. However, as with all resource-consuming features,

you must strike a balance between maximizing security and offering the performance

and usability the service is intended to provide. Clearly, a completely disconnected

host or router has total security; however, its ability to forward data or provide services

is substantially compromised.