If Your Lab Went Smoothly - Most Likely You Didn't Learn as Much as You Could Have!

As mentioned in my earlier blog, "The Classful vs. Classless Routing Behavior Dilemma", there was a problem with our lab last week. Classful routing behavior was working for us, as described in the lab. As it turns out, to get the lab to work correctly, we needed to disable CEF, Cisco Express Forwarding. With which platforms, which version of ios, the no ipclassless command stopped working, I am not sure. Doesn’t matter, really. What’s more important, I believe, is that we understand the difference between process switching and CEF so you know what it is you are disabling in the lab. No better time like the present to take a look at these two different technologies (there are others, as well, but let’s focus on process switching and CEF today).

As we have discussed already, there are three main steps to forwarding a packet through a router: 1) determine if the packet’s destination is reachable, 2) determine the next hop toward the destination, and the interface through which that next hop is reachable, and 3) rewrite the source and destination MAC address on the frame header so it will successfully reach its next hop. I am not going to go into a lot of detail, but I do want to briefly introduce several switch technologies used by Cisco IOS releases. Let’s start with process switching.

Process switching is available on every version of IOS, on every platform. With process switching, the forwarding decision and information used to rewrite the MAC header on the packet are taken from the RIB (routing Information Base) and the ARP table cache (which maps the MAC header information to the IP address of each host that is directly connected to the router). Processes that normally run on the router are not interrupted to process switch a packet.

The input interface processor detects there is a packet on the network media, and transfers the packet to the input/output memory on the router. The interface processor generates a receive interrupt, and during the interrupt, the central processor determines what type of packet it is. If it is an IP packet, the processor places the packet in an input queue and the interrupt is released. When the scheduler runs, it finds the packet in the input queue of ip_input and schedules the process to run. When ip_input runs, it consults the RIB to determine the next hop and the output interface, then consults the ARP cache to determine the correct physical layer address for this next hop. Ip_input then rewrites the packet’s MAC header, and places the packet on the output queue of the correct outbound interface. The packet is copied from the output queue of the outbound interface to the transmit queue of the outbound interface. The output interface processor detects the packet on its transmit queue, and transfers to packet onto the network media.

Cisco Express Forwarding (CEF) is advanced, Layer 3 IP switching technology. It stores the reachability and forwarding information in two different tables. An adjacency table holds the forwarding information and the CEF table holds the reachability information. The CEF table is called the FIB (Forwarding Information Base) table. Both are built without process switching any packets.

Whereas process switched technologies used the routing table, CEF uses this FIB table. Because the FIB lookup table contains all known routes that exist in the routing table, it eliminates route cache maintenance (fast switch technology). CEF uses a FIB to make IP destination prefix-based switching decisions. The FIB is conceptually similar to a routing table and maintains a mirror image of the forwarding information contained in the IP routing table. When routing or topology changes occur in the network, the IP routing table is updated and those changes are reflected in the FIB. The FIB maintains next-hop address information based on the information in the IP routing table. Because there is a one-to-one correlation between FIB entries and routing table entries, the FIB contains all known routes and eliminates the need for route cache maintenance associated with fast switching.

In addition to the FIB, CEF uses adjacency tables to prepend Layer 2 addressing information. The adjacency table maintains Layer 2 next-hop addresses for all FIB entries. When CEF mode is enabled, the CEF FIB and adjacency tables reside on the route processor (along with the routing table), and the route processor performs the express forwarding. When distributed CEF mode is enabled (dCEF), line cards maintain an identical copy of the FIB and adjacency tables. The line cards then perform the express forwarding between port adapters, relieving the route processor of involvement in the switching operation. Inter Process Communication mechanism acts as an interface between the route processor and the line cards to ensure synchronization of FIBs and adjacency table.

I hope this brief explanation of process switching (routing as we know it) and CEF gives you some idea of the difference between the two technologies. In order to see the difference between classful and classless behavior, as explained to us in our text, powerpoint, and lab of chapter 8, we needed to disable cef with the no ip cef command. As put in the title of this blog entry, if our labs run smoothly each week, we probably are not learning as much as we could!

Anyway, hope this helps!

Joanne

The Classful vs Classless Routing Behavior Dilemma

We had a very interesting time in our labs this week. One of the topics covered this week in our CCNA2 (CIT1122) Routing Class was Classful and Classless Routing behavior. We have been studying classfull and classless routing but, this week, focused on classful and classless routing behavior.

Unfortunately, or interestingly, the lab did not work as expected, using RIPv1, a classful protocol. According to what we read in our text and online curriculum, we should be able to use the "no ip classless" command with RIPv1. As a result of using that command, if we ping to a subnet that doesn't exist in the RIPv1 routing table, the packet destined to that subnet should be dropped. Because we were using the, "no ip classless" command, the router, as described in our studies, should not have been able to reach the default route. The ping should have failed.

I contacted Rick Graziani, author of our text and professor at Cabrillo Community College, and he is trying to get an answer for us.

The question we are asking is, does the "no ip classless" command still work in current IOS images for RIPv1? As stated above, in the lab this week, we found that it didn't matter if we disabled the "ip classless" command with the "no ip classless" command - RIPv1 still used the classless behavior and found the default route.

Below is a example with the routing table looking like this (I don't remember the exact networks but found this one on the Internet):

Gateway of last resort is 0.0.0.0 to network 0.0.0.0

172.16.0.0/24 is subnetted, 3 subnets
R 172.16.1.0 [120/1] via 172.16.2.2, 00:00:12, Serial0/1/0
C 172.16.2.0 is directly connected, Serial0/1/0
C 172.16.3.0 is directly connected, FastEthernet0/0
C 192.168.1.0/24 is directly connected, Serial0/1/1
S* 0.0.0.0/0 is directly connected, Serial0/1/1

Regardless if "no ip classless" or "ip classless" was in use, the ping to
the network 172.16.4.0 was successful (but with classfull behaviour shouldn't):


Router#ping 172.16.4.1

Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 172.16.4.1, timeout is 2 seconds:
!!!!!
Success rate is 100 percent (5/5), round-trip min/avg/max = 12/14/16 ms

As soon as we here back from Rick, I will update you with his findings. We now have him curious!!

Joanne

Load Balancing

As we have learned in our CIT1122 class, load balancing is used when a router has multiple paths to a destination when forwarding packets. It is a standard function of the Cisco IOS software for all of the routing protocols we study.

Load balancing occurs when a router receives multiple paths with the same administrative distance and the same cost to a destination. You can set load-balancing to work per-destination or per-packet.

Per-destination load balancing means the router distributes the packets based on the destination address. Given two paths to the same network, all packets for a specific destination go over the first path, all packets for a second destination on that same network would go over the seconed path.

Per-packet load-balancing means that the router sends one packet for destination1 over the first path, the second pacet for the same destination1 over the second path, and so on. Per-packet load balancing guarantees equal load across all links. For per-packet load balancing, the forwarding process determines the outgoing interface for each packet by looking up the route table and picking the least used interface. This ensures equal utilization of the links, but is a processor intensive task.

For most Cisco routers, per-destination load-balancing is the default. You can enable per-packet load-balancing with the ip route-cache command for a specific interface.

If you issue the show ip route command, you will see an asterick corresponding to the active route that is used for new traffic (single packet or entire flow to a destination - depending on what method you are using). For per-packet load-balancing, the asterisk points to the interface over which the nexst packet is sent. For per-destination load-balancing, the asterisk points to the interface over which the next destination flow is sent. Check this out, in the lab, such as Lab 7.5.1. Let me know what you observe - I will be curious as to your findings/reflections.

There is more to know about load-balancing, but this should get you started. You will learn more in your CCNP class about per-packet load-balancing (process-switching) and per-destination load-balancing (fast-switching).

Hope this helps!

There was recently an article in the Naperville Sun by Katie Morrell, "Hiring experts offer unconventional job tips", Thursday, September 9, 2010. She had indicated that the Naperville Sun had consulted with a few job search experts to bring you some cutting-edge job-hunting tips. Things you might do beyond just posting your resume on Monster and Career Builder. I thought I would share these tips with you:

1) Keep in Touch
"Try to keep in touch long after a job you've applied for is filled," suggested Fran Liontakis, regional vice president for Robert Half International, a job search firm in Naperville. "Oftentimes, the person they choose may not be the best fit. The person who continues to follow-up may be the potential backup. Try sending a friendly e-mail once a week."

2) Work for Free
"Offer to work pro bono for a period of a month," Liontakis said, "Tell them you want to volunteer your time for a period to highlight your skills. At the end of the time, tell them that if you don't have the skills they want, you will part ways without obligation."

3) Link in
"You need to have a well-developed profile on LinkedIn," said John Myers, managing partner of Kensington Internalional, a talent management consulting firm in Oak Brook. "Make sure you know how to expand it well beyond the people you know. Most people don't think they have a very big network and think in finite terms. Your network is much bigger than you think LinkedIn casts a big net and if you purchase an upgraded membership, you will have the ability to directly communicate with those people. Today, more and more search firms are accessing LinkedIn for candidates."

4) Get involved
"Do volunteer work at a nonprofit organization that is aligned with the industry in which you are looking to work," said Liontakis. For example, if you are a credit specialist, you may want to volunteer your time at a consumer credit counseling service. This type of volunteering will give you networking opportunities."

5) Be creative
"Be creative about the ways you are presenting your skills," Liontakis said. "Some candidates send DVDs highlighting their experience. Don't do away with traditional resumes, but look for creative ways to capture the decsion maker's attention early on."

6) Help others help you
"When people ask you what they can do to help, make sure you are well-prepared," Myers said. "Present them with a list of companies you want to get introduced to and go down the list."

7) Act
"Be proactive," Liontakis said. "Let's say you've make it past the first interview. From there, try to make a business plan for the company on how to solve their problems. Putting in that extra time and creating extra ideas shows your interest."

8) Sell yourself
"Try approaching a company as an entrepreneur instead of a candidate," Myers said. "Package yourself with your own business card and materials that describe the value you can deliver. That way, you are offering your services for rent instead of for hire, but you aren't using a project firm as an intermediary, you are doing it yourself. "Instead of going in with your resume as a job candidate, you are going in and saying you can do a project. Oftentimes, those turn into offers."

Please keep in mind, these are just suggestions that I ran into a week or so ago. There are no guarantees here, just suggestions. I would love to hear from you as to job interviewing tips that have worked for you. I have some thoughts of my own that I will be sharing with you, as well.

Hope this helps - Joanne

Full-Time Configuration Technicians Needed

3 to 5 COD CIT students/alumni needed for a full-time Configuration Technician position. Other Roles, as well, as described below:

Supplier/Roles & Responsibilities

Supplier personnel, as required, shall attend coordination meetings as needed with CLIENT and OEM suppliers. Supplier shall provide the following personnel to ‘Jointly’ perform the services described in this Agreement:

(1) Depot Deployment Manager – This person will be responsible to work hand in hand with the assigned CLIENT employee Depot Lead role to plan, coordinate, and execute the CLIENT deployment schedules and various duties as performed in the depot per the CLIENT schedule of work. The Depot Deployment Manager shall dotted line report to the Senior Technical Director of the CLIENT ITO Evolving Technologies Operations Support team and will be located at the ITO Configuration Depot Center.
- The Depot Deployment Manager shall provide assistance to the Senior Technical Director of the CLIENT ITO Evolving Technologies Operations Support team as necessary to build deployment schedules, assist with project management planning, and ensure timely deployments are occurring in the field and administrative tasks as needed.
Responsibilities shall also:
 Serve as the primary interface between CLIENT and Supplier’s account team;
 Coordinate all Supplier activities to support the success of this relationship;
 Manage, escalate, and resolve any issues impacting SUPPLIER’s ability to meet CLIENT requirements.
 Facilitate and attend CLIENT meetings as necessary;
 Work with CLIENT focal points to understand CLIENT requirements.

(1) Installation Services Manager – This person will be responsible to plan, coordinate, and execute the CLIENT Mobile Office Installation deployment schedule per the CLIENT schedule of work.
- The Installation Services Manager will be located at the ITO Configuration Depot Center. The Installation Services Manager shall dotted line report to the Senior Technical Director of the CLIENT ITO Evolving Technologies Operations Support team.

One (1) Configuration Center Technical Lead –This person will be responsible to manage and coordinate all activities of Supplier’s staff in the ITO Configuration Depot. This Technical lead shall dotted line report to the Senior Technical Director of the CLIENT ITO Evolving Technologies Operations Support team.

Configuration Technicians – (Minimum 3 - 5 staffed on site) These personnel shall be responsible for day-to-day Services in accordance with the CLIENT schedule, the ITO Configuration Depot processes and Warranty / Break fix and / Hot swap / software re-configurement as required. Supplier is responsible to maintain the correct number of resources required to meet all obligations of the various support models and obtain SLA consistently, month over month, over and above set minimum staffing levels. These technicians shall be assigned to the ITO Configuration Depot and dotted-line’ report to the Senior Technical Director of the CLIENT ITO Evolving Technologies Operations Support team.

One (1) Warehouse Lead –This person will be responsible to manage and coordinate all activities of Supplier’s staff in the ITO Configuration Depot Warehouse. This lead shall dotted line report to the Senior Technical Director of the CLIENT ITO Evolving Technologies Operations Support team.

Warehouse Services personnel – (Minimum 3 staffed on site) These person(s) shall be responsible for the day-to-day warehouse services in the ITO Configuration Depot. They shall be responsible for receipts of Supplier’s goods at the CLIENT dock location or in the depot through receipt and inventorying of goods, in addition to preparation of Laptops for activation and configuration and Shipment to CLIENT. Supplier is responsible to maintain adequate resources required to meet all obligations of the various support models and obtain SLA consistently, month over month over and above set minimum staffing levels. The Warehouse Services team members shall be assigned to the ITO Configuration Depot and dotted-line’ report to the Senior Technical Director of the CLIENT ITO Evolving Technologies Operations Support team.

Note: Looking for 3 to 5 Configuration Technicians ($40,000 to $50,000). The Configuration Center Technical Lead position ($45,000). Windows OS and some Cisco needed.

If interested, email me via wagnerjo@cod.edu.

On August 25th, I blogged on COD's Alpha Beta Gamma. As a result, a former student sent me an email with the following question on ABG:

"Was looking at your blog and saw the posting on ABG. I'm interested in learning more about it since I meet the requirements.
What advantages does it bring to a resume? What does it involve? I work full time now and have classes Tues and Thur night, so if I had to attend meetings or something
I might be hard pressed to find the time. Any other info you could give me would be appreciated. Thanks. Dan"

I turned Dan's question over to Kathy Horton, ABG advisor, for an answer. Here is what she told us:

"Hi Joanne and Dan. Thank you both for your interest in ABG. It is an international honor society for business and technology majors in two-year institutions. To qualify, a student must have a 3.0 GPA, 12 hours of semester credit at COD completed, and be a business or technology major.

Dan, if you meet those qualifications, please return the attached completed form to me, per the instructions. We will let you know what to do next when we receive your application.

And why would you want to do this? First of all, it recognizes your exceptional academic achievement. You can participate in an induction ceremony in the spring, attended by faculty and administrators. This recognition should be a part of your resume and included on academic and job applications. Other advantages include:

· Leadership opportunities

· Special scholarships to transfer schools

· Recognition at COD graduation

· Participation in ABG essay competitions for scholarship monies

· Networking opportunities"

Please let Kathy or me know if you have any other questions about ABG. Hope this helps - Jo

Great Website for IINS 640-553 exam

Hi Joanne,
Found a great website for the IINS 640-553 exam. They cover quite a bit and have LabSim examples
for port security and Cisco SDM, also a Zone Based Firewall LabSim that is being updated.
Hope this helps out other students who are looking for some way to study for IINS.

Dan

http://www.securitytut.com/

Jr. Systems Administrator

This lead comes to us from Dan Dunhac: EmailJob@site.CareerBuilder.com.
Thanks Dan!

NOC Support Engineer

The Network Operations Center (NOC) Support Engineer will be one of the resources responsible for year round 24 hour and 7 day a week support and monitoring of the website infrastructure (applications and associated hardware).
• The NOC resource will ensure that all interactions with the client requests and reports of issues are resolved in a prompt, professional and personable manner, meeting the business’ continuity objectives.
• The NOC resource will provide exceptional Level 1 & some Level 2 customer service.
• The NOC resource will diagnose, troubleshoot and resolve all phone, e-mail, and ticketing system inquiries, requests, and issues received from customers regarding site functionality and operations.
• The NOC resource will appropriately escalate those issues and inquiries to Level 2 Technical Operations Support (Site Ops, Sys Admin’s, DBA, DataMgmt, Help Desk) and continue to work with Level 2 Tech Ops support as necessary until the issue is resolved.
• The NOC resource will manage the collection of performance and availability metrics, capacity management metrics, and continuity of service metrics for reporting purposes.
• The NOC resource will be responsible for the installation and maintenance of the tools (i.e. Tivoli, KeyNote) utilized in the day to day operations of the NOC.
• Reporting to work onsite and on time, on a daily basis is an essential function of the job (rotating schifts).

If interested, contact Dave Galati at dgalati000@sbcglobal.net