What is Administrative Distance & Metric Distance?

I just had an email from a student asking, "what is administrative distance and Metric Distance?".  I will give a brief answer here, but if any of you want more detail, please let me know.

When a Cisco router has more than one route to a particular destination and those routes come from different route sources (directly connected, static, and/or dynamic routing protocol(s)), the router ios uses the administrative distance to decide which of those routes to place in the routing table (the best route(s)).

Whereas, the metric value is used when there is more than one way to get to a particular destination and all of the routes to that destination come from a single route source (i.e. RIP dynamic routing protocol).

As we discussed in class, the metric used by the routing protocol will be different, depending on the routing protocol. RIP uses hop count, Cisco’s OSPF uses bandwidth; EIGRP uses bandwidth and delay by default (but can be configured to include load and reliability).

The administrative distance value is set by Cisco and not an actual standard. However, other vendors do use it. The route that has the lower administrative distance will be preferred over the router with the higher administrative distance and will be added to the routing table. The term “trustworthy” is commonly used when defining administrative distance. The lower the administrative distance value, the more “trustworthy” the route.

I hope this helps - Joanne

Network Security Engineer, Chicago, IL

Hi Joanne!

I am in the process of looking for my replacement. I need a network security engineer that meets the following job description:

Must have a solid understanding and working knowledge of networking, security, server hardware and operating systems as well as the interdependencies between them. Additional Responsibilities: May be responsible for day-to-day coaching, providing on-the-job and formal training, reference materials, procedures, and system documentation. May interface with other stakeholders including vendors, application development and technical support staff. May provide inventory and asset management resources to the IT security operation, including office administrative supplies, security specific resources such as SecurID cards or cryptographic key management, specialized security software, etc. Must possess working knowledge of Security Vulnerabilitiy assessments; Information Security Standards and Practices; firewall technology and administration; knowledge of Intrusion Detection system technology and adminstration; public-key infrastructure technology. Windows and Unix Administration is a must.

If you know anyone who would qualify and is interested please pass this on. It is hard to find someone with this background in Chicago so I am reaching out to you.

Thank you!

Scott Otocki CISSP

Network Engineer Specialist

630-854-8204