What to Know Before Upgrading Your Cisco Router

What to Know Before Upgrading Your Cisco Router
Expanding the capacity of any high bandwidth network is always an involved process. The actual cost of upgrade hardware and the task of physically installing RAM memory into your Cisco routers' expansion slots is simple enough, but most high-capacity data networks serve production environments which demand fault-tolerance and as near to total uptime as possible. In order to build a network that can be relied upon to guarantee this level of service, network engineers need to plan a long way ahead. In addition to ensuring the servers, workstations, cabling and software can handle increasing loads for years to come, when planning a new segment, a good engineer will consider the possible lifetime cost and load of each and every crucial device on the network. This includes Cisco routers!

As it may be difficult to even temporarily disconnect a mission-critical router to upgrade its memory, one way to "future proof" your network is to upgrade the device at purchase - prior to installation. This may sound expensive, but in any truly high-bandwidth medium, the cost of downtime or loss of connectivity far outweighs the safe option of upgrading your routers memory to the maximum before installing it.

If you do indeed decide to take the path of pre-upgrading a Cisco router for life, you will be choosing to save yourself from ever having to take it out of commission in order to install new Cisco DRAM memory or flash. Though the cost may be significant, not upgrading presents even more significant risks. It's well known that a router is more likely to fail if it is run with insufficient RAM for it to cope with its workload.

This raises the question of Cisco memory will be enough over the lifetime of a given product. Unfortunately, there's no simple answer to this question: How much RAM a Cisco router is going to need changes depending on the enterprise and its scale, what sort of applications your network is (and will be) supporting, and of course, which series router you're using. Cisco makes some forecasts and recommendations available to customers to assist in making this judgment.

Generally, upgrading to the maximum memory your router is capable of supporting takes some of the guesswork out of this equation. The Cisco memory requirements for each are made available in individual the product specifications, and Cisco lists which product lines will be supported at least 18 months in advance. In this way, a diligent network analyst may make fairly accurate predictions of what their individual requirements will be for at least the next couple of years, and likely, much longer.

After checking the installation procedure and maximum upgrade capacity for your particular Cisco router, you have two options, either purchasing the memory directly from Cisco at a considerable markup, or from a memory reseller such as PC Wholesale. Memory resellers offer a tremendous advantage over purchasing directly from Cisco for the budget conscious company – many times their prices can be up to 90% off Cisco’s list price, for the same exact memory!

Upgrading Your Cisco Memory

Upgrading Your Cisco Memory
Almost all advanced Cisco routers and switches are equipped with the Cisco proprietary operating systems called the IOS (Internetwork Operating System). Cisco PIX firewalls have a special operating system, the PIX Finesse OS.

In some versions of the IOS, there is a MIB (Management Information Base) module integrated into the IOS operating system. The MIB is an operating system component included with all recent IOS distributions that allows network administrators to view and manage device memory over the network. MIB is prerequisite software for other applications that deal with Cisco memory management, reporting data to RME (Resource Manager Essentials) and during installation of other additional software to a given device.

Before discussing the reasons to upgrade your router's memory, the following is description of the different types of memory that used in a Cisco product.

Processor Memory

This memory acts similar to the CPU cache in a computer, controlling all basic computing operations of your switch or router. Regardless of any other memory being used, the processor memory is always the first memory that is accessed and used. All the files needed for booting and essential system files required for functioning for any Cisco device are stored in the processor memory. If you are using a product that has IOS before 11.1, then the total of all types of memory is reported as the processor memory.

Flash Memory Card/Disk or Cisco Memory Card

The flash memory is a special type of programmable memory that is used to store images of the IOS software on it, in addition the flash memory is used to upgrade versions of the router or switch being used. The term 'flashing a product' means upgrading the version of IOS stored on the flash memory card.

Shared Memory/RAM (Random Access Memory)

The reason this is often referred to as the shared memory, is that it is erased every time the router is restarted or when the memory is deliberately cleared. This memory is usually the easiest to upgrade. The RAM stores all data that is temporary in nature, and upgrading the RAM usually helps improve the speed and the computing power of the Cisco product. It is generally cheaper than Flash memory, and manufactured both OEM by Cisco and by third party manufacturers, such as PC Wholesale.

While PIX firewalls and the routers that IOS runs on ultimately have finite processing power, this is often not the bottleneck that first limits their ability to grow. More often, IOS is hampered by having allocated as much (or more) dynamic Random Access Memory (DRAM) than it has available. Older firewalls and routers, which shipped with very small Cisco memory (Flash) cards, the factor limiting the usefulness of the hardware may be the Operating System installed on it.

IOS and PIX OS each have vastly larger memory footprints than they did as recently as a few years ago, and the current versions of these operating systems require more memory than many devices are equipped with. Both the RAM and Flash memory of a Cisco router can be upgraded. Such an upgrade may significantly extend the longevity of a network operating with older equipment. Two of the principal reasons to upgrade your devices memory to increase its speed and to run the most current version of Cisco IOS.

Increasing speed

Just like conventional computers, increasing the memory of a Cisco product increases its speed. If the product is a Cisco router or switch that handles large amounts of data over the network, increasing the RAM of the product can improve both the processing speed and the device's performance.

Upgrading the IOS

For devices with Cisco IOS 11.1 or older the only way to improve its performance is to upgrade the IOS. However, older Cisco hardware is usually not equipped with sufficient flash memory to store a newer version of the IOS. In this case, the only option is to upgrade the flash memory of the Cisco product. All versions of the Cisco IOS after version 11.1, used by most Cisco routers and non-firewall hardware around the world, has functionality to report MIB values over the network via SNMP (Simple Network Management Protocol), allowing network administrators and other authorized device managers to make queries to the database from across the network. Obsolete versions of the IOS, without the MIB module, do not have this functionality and can only report the size of processor memory.

Cisco CCNP Certification FAQ

Cisco CCNP Certification FAQ
To earn your CCNP, you've got to pass some very rigorous Cisco exams, and you also need to know the rules regarding this important certification. In this article, I'll answer some of the most commonly asked questions regarding the CCNP.

Q: What exams do I need to pass to get my CCNP?

A: You have two options, a three-exam path and a four-exam path. Currently, the four-exam path consists of rigorous exams on advanced routing techniques (BSCI), advanced switching (BCMSN), remote access methods (BCRAN), and advanced troubleshooting techniques (CIT). The three-exam path combines the BCMSN and BSCI exams into a single exam, the Composite exam.

Q: Do I have to take them in any order?

A: No, the order is up to the candidate. Most CCNP candidates take the BSCI exam first and the CIT exam last, but again this is up to the candidate.

Q: What else do I have to do to get the CCNP?

A: You must earn your CCNA before you can be CCNP certified (as well as passing the exams, of course).

Q: Is there a recertification requirement?

A: Cisco CCNP certifications are valid for three years. During that time, you must either pass the Composite exam, the BSCI and BCMSN exams, or pass any CCIE written exam.

Q: What if I don't recertify within the three-year period?

A: You must then meet whatever CCNP requirements there are at that time, from the beginning. It's easier to make sure you recertify!

Becoming CCNP certified is a great boost to your career and your confidence, and as with any Cisco certification, it's up to you to stay current with the CCNA and CCNP requirements. Visit the Career Certification section of Cisco's website regularly to learn about the program's requirements and changes.

Setting Up As A Cisco Network Engineer

Setting Up As A Cisco Network Engineer
The individual who works as a Cisco network engineer is one that has some of the most sought after training in the world of Internet technology. Cisco systems are widely used around the globe in the networking of devices and various computer systems. Because of this, individuals who have an inner knowledge of Cisco and can keep the system up and running are greatly in demand.

Though many depend on their computers for a number of daily tasks, few have the skills or knowledge to understand the ins and outs of the systems they use. When that system needs maintenance or repair, most find it is necessary that a professional be used to deal with these issues. This can not only keep a system in tip-top shape but also prevent costly mistakes from being made.

When one decides to become a Cisco network engineer, he or she will find there are a number of certifications and qualifications to achieve. For the most part, individuals will need a strong understanding of the basics. This often consists of an education that combines textbook learning with a hands-on environment.

The curriculum for this type of training teaches an individual how to troubleshoot Cisco Systems from start to finish. Those who pursue this field should have an eye for detail. Learning the various aspects of what can go wrong during such things as installations, upgrades and configurations is what makes the Cisco engineer so important.

Once an individual learns the essential basics, it is then that he or she can move on to other types of certifications. It is not uncommon for some Cisco engineers to carry a number of different certifications under their belt. This not only gives them more career options but also increases their earning potential.

As with all computer-based vocations, Cisco engineers will find they must regularly update their skills. The world of technology simply moves at too fast a pace to assume that this is unnecessary. However, this means a Cisco network engineer can look forward to always being on the cutting edge of technology thanks to their career.

Because it is such a highly popular aspect of Internet technology, finding institutions that offer training is hardly difficult. However, before making a final decision, prospective students should make sure the course is accredited and offers all the necessary skills. Students can expect to invest as little as a year to earn their Cisco Certified Networking Associate, or CCNA.

Once an individual earns their CCNA, he or she can then move on to other certifications if so desired. As some Cisco Systems qualifications only last up to three years, individuals will be required to update their credentials in order to stay certified. While each certification will require a fee to update, the good news is most employers are willing to pick up the tab for their employees.

For those individuals looking to take on this type of training, it is important that the program be fully accredited. This ensures that a certification will be considered legitimate upon completing the required coursework. Without legitimate certification, it will be next to impossible to find employment in this field.

Becoming a Cisco network engineer promises to be one of the most stable IT careers a person can choose. Unlike other vocations that become outmoded with time, the use of computers guarantees there will always be a need for the services of a Cisco engineer. It is also one of the few professions that allow an individual to take their career as far as they see fit.

Cisco Memory Types and Their Function

Cisco Memory Types and Their Function
Most Cisco networking hardware, with the exception of the Cisco PIX firewall series, ships with the Cisco Inter-network Operating System, or IOS. IOS hardware includes network routers, switches, and other similar devices. The basic design of most of this hardware controls the types of memory a device is equipped with, and what functions the various types of Cisco memory serve. At the hardware level, there are four main types of Cisco memory: DRAM, EPROM, NVRAM, and Cisco Flash Memory.

DRAM, or Dynamic Random Access Memory caters to two main device requirements. The first of these is known as Processor Memory which is reserved for exclusive access by the CPU, which it uses when executing software running on the Cisco IOS platform. Processor Memory also stores crucial data that is used constantly, like the configuration settings in current use, and any routing tables. The second is Shared Memory, also known as I/O Memory, or Cisco Packet Memory. The function of Packet Memory is simple and self-explanatory: Data coming in and being sent out is buffered to the Packet Memory portion of the available DRAM before it is transmitted over the network interface.

EPROM, or Erasable Programmable Read-Only Memory is usually referred to as a BootROM. EPROM is generally programmed at some point during the latter stages of manufacture, and cannot generally be changed by consumers. In Cisco devices, EPROM is generally loaded with two crucial firmware components. The first is a boot loader which takes over should the device fail to find a valid bootable image in Flash Memory, and provides alternate boot options. If even this failsafe should fail, the second firmware application installed on Cisco EPROM is used, the ROM Monitor. ROM Monitor has a user interface and includes options for troubleshooting failures of the ROM chips.

In Cisco devices, NVRAM, or Non-Volatile Random Access Memory, stores important configuration information that is used by IOS during boot and by some programs during startup, which is stored in the Startup Configuration File. NVRAM also allows the functionality provided by the Cisco Software Configuration Register, which allows a device to be booted and selection from multiple Cisco IOS images that may be available in Flash Memory. It is sometimes called Shared Memory.

Cisco Flash Memory is the most diverse of each of these types, and it comes in many forms, however, its primary use is to store a bootable Cisco IOS image from which a device can start. Most devices have onboard Flash memory from which the device boots, however, some equipment - particularly higher-end hardware like Cisco GSR routers - also have the capability to boot from an image stored on a Cisco Flash Memory card, which is removable. Regardless of the memory type, it is important to find a memory reseller who is reliable. Things to look for when choosing a memory reseller are that they have memory for every Cisco device in stock, offer a warranty on the memory, and have technical people with whom you can speak if you have any problems.

Cisco CCNA /CCNP: How And Why To Build An Etherchannel

Cisco CCNA /CCNP: How And Why To Build An Etherchannel
CCNA and CCNP candidates are well-versed in Spanning-Tree Protocol, and one of the great things about STP is that it works well with little or no additional configuration. There is one situation where STP works against us just a bit while it prevents switching loops, and that is the situation where two switches have multiple physical connections.

You would think that if you have two separate physical connections between two switches, twice as much data could be sent from one switch to the other than if there was only one connection. STP doesn't allow this by default, however in an effort to prevent switching loops from forming, one of the paths will be blocked.

SW1 and SW2 are connected via two separate physical connections, on ports fast0/11 and fast 0/12. As we can see here on SW1, only port 0/11 is actually forwarding traffic. STP has put the other port into blocking mode (BLK).

SW1#show spanning vlan 10

(some output removed for clarity)

Interface Role Sts Cost Prio.Nbr Type

Fa0/11 Root FWD 19 128.11 P2p

Fa0/12 Altn BLK 19 128.12 P2p

While STP is helping us by preventing switching loops, STP is also hurting us by preventing us from using a perfectly valid path between SW1 and SW2. We could literally double the bandwidth available between the two switches if we could use that path that is currently being blocked.

The secret to using the currently blocked path is configuring an Etherchannel. An Etherchannel is simply a logical bundling of 2 - 8 physical connections between two Cisco switches.

Configuring an Etherchannel is actually quite simple. Use the command "channel-group 1 mode on" on every port you want to be placed into the Etherchannel. Of course, this must be done on both switches if you configure an Etherchannel on one switch and don't do so on the correct ports on the other switch, the line protocol will go down and stay there.

The beauty of an Etherchannel is that STP sees the Etherchannel as one connection. If any of the physical connections inside the Etherchannel go down, STP does not see this, and STP will not recalculate. While traffic flow between the two switches will obviously be slowed, the delay in transmission caused by an STP recalculation is avoided. An Etherchannel also allows us to use multiple physical connections at one time.

Here's how to put these ports into an Etherchannel:

SW1#conf t

Enter configuration commands, one per line. End with CNTL/Z.

SW1(config)#interface fast 0/11

SW1(config-if)#channel-group 1 mode on

Creating a port-channel interface Port-channel 1

SW1(config-if)#interface fast 0/12

SW1(config-if)#channel-group 1 mode on

SW2#conf t

Enter configuration commands, one per line. End with CNTL/Z.

SW2(config)#int fast 0/11

SW2(config-if)#channel-group 1 mode on

SW2(config-if)#int fast 0/12

SW2(config-if)#channel-group 1 mode on

The command "show interface trunk" and "show spanning-tree vlan 10" will be used to verify the Etherchannel configuration.

SW2#show interface trunk (some output removed for clarity)

Port Mode Encapsulation Status Native vlan

Po1 desirable 802.1q trunking 1

SW2#show spanning vlan 10 (some output removed for clarity)

Interface Role Sts Cost Prio.Nbr Type

Po1 Desg FWD 12 128.65 P2p

Before configuring the Etherchannel, we saw individual ports here. Now we see "Po1", which stands for the interface "port-channel1". This is the logical interface created when an Etherchannel is built. We are now using both physical paths between the two switches at one time!

That's one major benefit in action let's see another. Ordinarily, if the single open path between two trunking switches goes down, there is a significant delay while another valid path is opened - close to a minute in some situations. We will now shut down port 0/11 on SW2 and see the effect on the etherchannel.

SW2#conf t

Enter configuration commands, one per line. End with CNTL/Z.

SW2(config)#int fast 0/11

SW2(config-if)#shutdown

3w0d: %LINK-5-CHANGED: Interface FastEthernet0/11, changed state to administratively down

SW2#show spanning vlan 10

VLAN0010

Spanning tree enabled protocol ieee

Interface Role Sts Cost Prio.Nbr Type

Po1 Desg FWD 19 128.65 P2p

SW2#show interface trunk

Port Mode Encapsulation Status Native vlan

Po1 desirable 802.1q trunking 1

The Etherchannel did not go down! STP sees the Etherchannel as a single link therefore, as far as STP is concerned, nothing happened.

Building an Etherchannel and knowing how it can benefit your network is an essential skill for CCNA and CCNP success, and it comes in very handy on the job as well. Make sure you are comfortable with building one before taking Cisco's exams!

Cisco Certification: Recertifying Your CCNA And CCNP

Cisco Certification: Recertifying Your CCNA And CCNP
Once you get your CCNA and CCNP, you can't just rest on your accomplishment. You've got to continue to study and add to your skill set - and then prove to Cisco you've been doing just that by recertifying.

Recertification sounds like a pain, but it's actually one of the best things to ever happen to computer certification, and it helps your career as well. One trap many LAN and WAN personnel fall into is that they fail to keep up with changes in technology, and if they happen to be laid off or want to change jobs, they're unable to because they didn't keep their skill set up.

Cisco's recertification policies ensure that if you want to keep your CCNA, CCNP, or one of the other valuable Cisco certifications, you've got to take a recertification exam.

As of November 2005, to recertify as a CCNA, you need to pass either the current CCNA exam, ICND exam, or any 642 professional level or Cisco Qualified Specialist exam. (This does not include Sales Specialist exams.) Passing a CCIE written qualification exam also recertifies you as a CCNA. CCNAs are valid for three years.

For the CCNP, you need to pass the 642-891 Composite exam, a CCIE written qualification exam, or BOTH the BSCI and BCMSN exams (642-801 and 642-811, respectively.) CCNP certifications are valid for three years.

As you can see, you've got quite a few options either way. The one classic mistake you must not make is waiting too long to begin preparing for the exams, and give yourself a little leeway just in case you don't recertify the first time around. Once the deadline passes, your certification is gone, and in the case of the CCNP that means taking all the exams again.

As a professional, it's your responsibility to keep up with changes in the Cisco certification world, and this includes changes in the recertification program. Make a point of visiting the "Learning And Events" section of Cisco's website regularly to look for changes in the certification program. And while you're there, you just might see another cert that catches your eye!