The FIFO queuing mechanism
FIFO queuing has no classification because all packets belong to the same class. Packets are dropped when the output queue is full – this process is known as tail dropping. The scheduler services packets in the order in which they arrive. The software FIFO queue is basically an extension of the hardware FIFO queue.

Although FIFO queuing might be regarded as the fairest queuing mechanism, it has some significant drawbacks:

• FIFO is extremely unfair when an aggressive flow is contesting with a fragile flow. Aggressive flows send a large number of packets, many of which are dropped. Fragile flows send a modest amount of packets, and most of them are also dropped because the queue is always full due tothe aggressive flow. This type of behavior is called starvation.
• Short or long bursts cause a FIFO queue to fill. Packets entering an almost-full queue have to wait a long time before they can be transmitted. At another time, the queue might be empty,causing packets of the same flow to experience almost no delay. Such variation in delay is called jitter.

In spite of such drawbacks, FIFO is still the most-used queuing mechanism because of the following benefits:

• FIFO is simple and fast. Most high-end routers with fast interfaces are not really affected by problems such as starvation and jitter. Furthermore, routers are not capable of complex classification and scheduling when they have to process a large number of packets per second. FIFO is, therefore, the most suitable queuing mechanism on these router platforms.
• FIFO is supported • on all platforms.
• FIFO queuing is supported in all versions of Cisco IOS.

To enable FIFO, you need to disable WFQ, which is automatically enabled on interfaces with less than 2Mbps of bandwidth.

The WFQ queuing mechanism
WFQ was introduced to address the problems associated with other queuing mechanisms. For example, FIFO queuing causes starvation, delay, and jitter, and the PQ queuing mechanism causes starvation of other lower priority classes and suffers from all the problems associated with FIFO within each of the four queues that it uses for prioritization. CQ causes long delays and also suffers from all of FIFO’s problems within each of the 16 queues that it uses for traffic classification. WFQ was developed to alleviate these problems by

• having a dedicated queue for each flow – this means there is no starvation, delay, or jitter within the queue
• allocating bandwidth fairly and accurately among all flows, which results in minimum scheduling delay and guaranteed service
• using IP precedence as weight when allocating bandwidth

WFQ uses automatic classification, which means that manually defined classes are not supported. WFQ dropping is not a simple tail dropping process. Instead, WFQ drops the packets of the most aggressive flows. The WFQ scheduler is a simulation of a time-division multiplexing (TDM) system. The bandwidth is fairly distributed to all active flows.

WFQ is supported on most Cisco routers, as well as on Versatile Interface Processors (VIPs). The implementation of WFQ on the VIP differs slightly from its implementation on the majority of Cisco platforms. For example, classification identifies a flow and assigns a queue to the flow, and weight is used for scheduling to give proportionately more bandwidth to flows with a higher IP precedence. In addition, the tail-dropping scheme is improved to drop packets of the most aggressive flows.

Advantages and disadvantages of WFQ queuing
WFQ offers a number of advantages over other queuing mechanisms:

• it’s simple to configure, so no manual classification is necessary
• it guarantees throughput to all flows
• it drops the packets of the most aggressive flows
• it’s supported on most platforms
• it’s supported in all IOS versions

Nevertheless, there are also a number of drawbacks associated with WFQ:

• it’s not always possible to have one flow per queue
• it does not allow manual classification
• it cannot provide fixed guarantees
• its classification and scheduling mechanisms are complex

Despite these drawbacks, WFQ is a useful queuing mechanism, and it is automatically enabled on all interfaces that have a default bandwidth of less than 2 Mbps.

As a summary
First-in-first-out (FIFO) and weighted fair queuing (WFQ) are the two main default queuing mechanisms implemented on Cisco routers. Although FIFO is the fairest queuing mechanism, it has some significant drawbacks in that its use can cause the queuing problems known as starvation, delay, and jitter. Despite this, FIFO is the most suitable queuing mechanism for high-end router platforms that aren’t seriously affected by these problems. FIFO is supported on all platforms and all versions of Cisco IOS.

Developed to resolve some of the problems resulting from the use of basic queuing methods such as FIFO, WFQ dynamically divides available bandwidth by a calculation based on the total number of flows and the weight of each given flow. Supported on most platforms and on all versions of Cisco
IOS, WFQ has the advantage of being simple to configure. Other benefits include the ability to drop the packets of the most aggressive flows and to guarantee throughput to all flows. However, WFQ also has a number of drawbacks. It does not allow manual classification and it cannot provide fixed
guarantees. Furthermore, its classification and scheduling mechanisms are complex, and it’s not always possible to have one flow per queue in WFQ.

Components of a network

Because companies have adopted networks as part of their business strategy, they typically subdivide and map corporate networks to the corporate business structure. In the figure, the network is defined based on the grouping of employees (users) into a main office and various remote access locations.

A main office is a site where everyone is connected via a LAN and where the bulk of corporate information is located. A main office can have hundreds or even thousands of people who depend on network access to do their jobs. It may have several LANs, or it may be a campus that contains several buildings. Because everyone needs access to central resources and information, it is common to see a high-speed backbone in a LAN as well as a data center with high-performance computers or servers and networked applications.

A variety of remote access locations connect to the main office or each other using WAN services as follows:

• In branch offices, smaller groups of people work and connect to each other via a LAN. To connect to the main office, these users must use WAN services such as Integrated Services Digital Network (ISDN). Although some corporate information may be stored at a branch office, it is more likely that branch offices have local network resources, such as printers, but have to access information directly from the main office.
• A home office is where individuals are set up to work from their own home. Home office workers most likely require on-demand connections to the main office or a branch office to access information or use network resources such as file servers.
• Individuals who are mobile users connect to the main office LAN when they are at the main office, at the branch office, or on the road. Their network access needs are based on where they are located.

In order to understand what types of equipment and services to deploy in a network and when to deploy them, it is important to understand the business and user needs. The figure shows how to map an organization’s business or user requirements to a network.

Computer networks

In this example, the business needs may require LAN connectivity within the campus to interconnect the servers and end-user PCs, and WAN connectivity to connect the campus to the remote branch office and telecommuters. The WAN connection to the remote branch office requires a permanent connection, such as a leased line, and the home office connection requires a dial-up connection, such as ISDN.

Network applications

Network applications are software programs that run between different computers connected together on a network.

Some of the more common uses of network applications include using a web browser program to find content from the World Wide Web, or using an e-mail program to send e-mails over the Internet.

Network applications are selected based on the type of work that needs to be done. A complete set of application-layer programs is available to interface with the Internet. Each application program type is associated with its own application protocol. Some examples include:

• HTTP is the World-Wide-Web communications protocol used to connect to web servers. Its primary function is to establish a connection with a web server and transmit HTML pages to the client browser.
• Post Office Protocol 3 (POP3) is an application-layer protocol supported by e-mail programs for the retrieval of electronic mail. POP3 is a standard e-mail server commonly used on the Internet. It provides a message storage container that holds incoming e-mail until users log on and download their messages.
• File Transfer Protocol (FTP) is a simple file utility program for transferring files between remote computers, which also provides for basic user authentication.
• Telnet is a remote access application and protocol for connecting to remote computer consoles, which also provides for basic user authentication. Telnet is not a graphical user interface but is command-line driven or character mode only.
• Simple Network Management Protocol (SNMP) is used by network management programs for monitoring the network device status and activities.

It is important to emphasize that the application layer is just another protocol layer in the OSI model or TCP/IP protocol stack. The programs interface with application layer protocols.

Sending e-mail

E-mail client applications, (such as Eudora, Microsoft Mail, Pegasus, and Netscape Mail) all work with the POP3 protocol. The same principle is true with web browsers. The two most popular web browsers are Microsoft Internet Explorer and Netscape Communicator. The appearance of these two web browser programs is very different, but they both work with the application layer HTTP protocol.

Electronic mail enables you to send messages between connected computers. The procedure for sending an e-mail document involves two separate processes – sending the e-mail to the user’s post office, which is a computer running the POP3 server software, and delivering the e-mail from that post office to the user’s e-mail client computer, which is the recipient.

According to the vendor ,the Original Cisco Console Cable worth approximate RM100 above (60USD++). Usually Cisco console cable only come with each Cisco product you bought, but I found that ebay just sold at around 5USD to 10USD exclude shipping fees, while local website sold at RM60 above.

Should be those user who bough a lot Cisco switches and router, and they only use few to configure their Cisco device.

I was thinking does any Cisco’s Freak out there custom DIY their own Cisco Console Cable? I guess I am one of the “freak” who plan to do it.

Before I get start to DIY Cisco Console Cable, I require to know the arrangement of the cable. Arrangement on the RJ45 pin and another end at DB9 port.

Let study on the serial port numbering location 1st (DB9),  and RJ45 numbering location 1st. below are the port number for DB9 connector and RJ45 port number:

DB 9 Port Pin Number

RJ45 Pin Number

The color code for Cisco Console Cable as below:

rj45-1 to db9-8

rj45-2 to db9-6

rj45-3  to  db9-2

rj45-4 to db9-5

rj45-5 to db9-5

rj45-6 to db9-3

rj45-7 to db9-4

rj45-8 to db9-7

To confirm the above Cisco Console Cable color code correct, I require to do some verification. I require a Multimeter, mostly I will prefer tone mode, which mean the positive (Red) and negative (Black) touch together, will hv beep sound from the multimeter.

I require a  mini gender changer, male to male type, shown as below:

I connected this mini gender changer to the Cisco Console Cable’s Serial Port end as shown the picture below:

I need to use either 1 end of the multimeter to point to the RJ45′s Pin 1, and another end touching each pin on the DB9 serial connector until the beep tone occur. Record down which pin is come from RJ45′s Pin 1 (as above stated, RJ45′s Pin 1 connected to Db9′s Pin

Repeat the same step for RJ45′s Pin 2 until Pin 8, the result will be as above Cisco console cable color code.

After get known all the color code, now you require to get a soldering iron, and also a female db9 connector.

Solder the RJ45 cable to the DB9 Connector according to the cisco console cable color code above

You can get variety of db9 connector which come with cover, just like as below. I does not know what this kind of connector call, but it is very convenience just to have 1 pcs of this DB9 to RJ45 connector.

If you interested to DIY your own Cisco Console Cable, you can have a try, the above Cisco Colsole Cable color code has been proven correct by me. To ensure all the thing goes smoothly, it is advice to test it your self before you create your own console cable.

Happy “Do it Your Self” Cisco Console Cable.

• A network interface card (NIC), pronounced “nick,” is also called the LAN adapter, or just the network interface. This card typically goes into an ISA, PCI, or PCMCIA (PC card) slot in a computer and connects to the network medium. It then connects to other computers through the network media.
• Media refers to the various physical environments through which transmission signals pass. Common network media include twisted-pair, coaxial, and fiber-optic cable, and even the earth’s atmosphere through which wireless transmission occurs.
• A protocol is a set of rules. In the case of a network protocol, it is a set of rules by which computers communicate. The term “protocol suite” describes a set of several protocols that perform different functions related to different aspects of the communication process.
• Cisco IOS software which runs on Cisco equipment and devices, is the industry-leading and most widely deployed network system software. It delivers intelligent network services for enabling the rapid deployment of Internet applications.

Cisco IOS software provides a wide range of functionality, from basic connectivity, security, and network management to technically advanced services. The functionality of Cisco IOS software is the result of a technological evolution. First-generation networking devices could only store and forward data packets.

Today, Cisco IOS software can recognize, classify, and prioritize network traffic, optimize routing, support voice and video applications, and much more. Cisco IOS software runs on most Cisco routers and Cisco switches. These network devices carry most of the Internet traffic today.

• Network operating system (NOS) usually refers to server software such as Windows NT, Windows 2000 Server, Windows Server 2003, Novell NetWare, UNIX, and Linux. The term sometimes refers to the networking components of a client operating system such as Windows 95 or the Macintosh OS.
• Connectivity devices refer to several different device types, all of which are used to connect cable segments, connect two or more smaller networks (or subnets) into a larger network, or divide a large network into smaller ones. The term encompasses repeaters, hubs, switches, bridges, and routers.

The following are three categories of networks:

• A local-area network (LAN) is a network that is confined to a limited geographic area. This area can be a room, a floor, a building, or even an entire campus.
• A metropolitan-area network (MAN) is a network that is larger in size than a LAN and smaller in size than a WAN. This is a network that covers approximately the area of a large city or metropolitan area.
• A wide-area network (WAN) is made up of interconnected LANs. It spans wide geographic areas by using WAN links such as telephone lines or satellite technology to connect computers in different cities, countries, or even different continents.

Network structure is described in the following two ways:

• The logical topology is the path that the signals take from one computer to another. The logical topology may or may not correspond to the physical topology. For instance, a network can be a physical “star,” in which each computer connects to a central hub, but inside the hub the data can travel in a circle, making it a logical “ring.”

The physical topology refers to the layout or physical shape of the network, and includes the topologies in this table.

Bus – Computers arranged so that cabling goes from one to another in a linear fashion

Ring – When there are no clear beginning points or endpoints within a topology, forming a circle.

Star – If the systems “meet in the middle” by connecting to a central hub

Mesh – When multiple redundant connections make pathways to some or all of the endpoints.

In recent days, Cisco Study Group of Experts for the Cisco Certified Voice Professional (CCVP) released a new test plan. CCVP: Cisco Unified Call Manager and CCVP: Cisco Unified Communications Manager. Originally a simple two divided CCVP section, CCVP: Cisco Unified CallManager and CCVP: Cisco Unified Communications Manager, candidates can choose according to one of their own test cases.

The 2 part of CCVP certification requires candidates to participate in five examinations, three of which are compulsory in both directions, the subjects must be passed the CVOICE Cisco exams, the latest release of the examination number (642-436) This is with the CCVP: Cisco Unified CallManager authentication and released, CCVP certification have been obtained by the people, may choose to attend in July in the old version of CVOICE (642-432) exam, to obtain updates.  Cisco Exam 2 is another quality of service (QoS) 2.2 exam number (642-642) and Cisco’s failure to deal with the examination, the examination number (642-426).

Cisco Unified CallManager is the unique direction of the examination is the gateway Cisco exam (642-453) and new or old versions of the Cisco IP phone examination, the examination for No. (642-444) and. ?642-445)? (642-445).

Cisco Unified Communications Manager of the examination requirements of the direction of three compulsory examination subjects with two new test, these two new test were: IP Phone 6.0 1 (642-446) and 2 (642-456).

In addition, for all new test, Cisco all laboratory-based simulation training, are available.

“More than 50,000 worldwide and more than 70% of the world’s top 500 enterprises to use Cisco Unified Communications Certificate, which requires the current high level of IP telephony has been the people by increasing their own skills.” Cisco general manager LeJeanne Beliveau-Dunn said in a statement to comment on that. “CCVP provided to individuals in the field of IP phones and the promotion of play to their potential for career development opportunities.”

Ciscopedia , which is a dictionary that have the collection of cisco command line. This Cisco Pedia contain where, when, why, and how to use the cisco commands. Most of the new Network engineer, or begineer who like to learn Cisco Networking Commands must keep this as their weapon especially those CCNA, CCNP, CCIE holder.

In CiscoPedia, the content in this software are very informative, it will shows the command, the mode, the syntax, syntax description, command description, examples, misconceptions, and also related command, the most I like will be the examples, because for new network engineer who without much experience, can actually more understanding with the example provide.

Let pick a normal command like “VLAN”

Command:
copy

Mode:
Router#

Syntax:
copy {flash | ftp | nvram | running-config|startup-config | system | tftp} {flash | ftp | nvram | running-config | startup-config | system | tftp}

Syntax Description:
Specify a source filesystem and destination filesystem.

Command Description:
To copy any file from a source to a destination, use the copy EXEC command. Use the /erase option to erase the destination file system before copying.

Example:

Router(config)#copy tftp flash

Misconceptions:
None

Related Commands:
cd
dir
erase
delete

You can always get free stuff, software download at iCalvyn.com, but please do remember “give and take“, appreciate if able to provide me a review and link back if you like this Cisco Pedia, cisco command dictionary, or sign up my feed to get more valuable update.

CiscoPedia Download Link: hxxp://rap*idsha*re.com/files/175464175/CiscoPedia_3_0.rar

Router>enable
Password:
Password:
Password:
% Bad secrets

Router>show version
Cisco IOS Software, 2800 Software (C2800NM-ADVIPSERVICESK9-M), Version 12.4(15)T1, RELEASE SOFTWARE (fc2)
Technical Support: http://www.cisco.com/techsupport
Copyright (c) 1986-2007 by Cisco Systems, Inc.
Compiled Wed 18-Jul-07 06:21 by pt_rel_team

ROM: System Bootstrap, Version 12.1(3r)T2, RELEASE SOFTWARE (fc1)
Copyright (c) 2000 by cisco Systems, Inc.

System returned to ROM by power-on
System image file is “c2800nm-advipservicesk9-mz.124-15.T1.bin”

This product contains cryptographic features and is subject to United
States and local country laws governing import, export, transfer and
use. Delivery of Cisco cryptographic products does not imply
third-party authority to import, export, distribute or use encryption.
Importers, exporters, distributors and users are responsible for
compliance with U.S. and local country laws. By using this product you
agree to comply with applicable laws and regulations. If you are unable
to comply with U.S. and local laws, return this product immediately.

A summary of U.S. laws governing Cisco cryptographic products may be found at:

http://www.cisco.com/wwl/export/crypto/tool/stqrg.html

If you require further assistance please contact us by sending email to
export@cisco.com.

cisco 2811 (MPC860) processor (revision 0×200) with 60416K/5120K bytes of memory
Processor board ID JAD05190MTZ (4292891495)
M860 processor: part number 0, mask 49
2 FastEthernet/IEEE 802.3 interface(s)
239K bytes of NVRAM.
62720K bytes of processor board System flash (Read/Write)

Configuration register is 0×2102

Router>

Just remember the current cisco router register number “2102“, after that, on and off your cisco router, press crtl + backspace + break to enter the NVram

Self decompressing the image :
######################
monitor: command “boot” aborted due to user interrupt
rommon 1 > confreg 2142
rommon 2 > reset
System Bootstrap, Version 12.1(3r)T2, RELEASE SOFTWARE (fc1)
Copyright (c) 2000 by cisco Systems, Inc.
cisco 2811 (MPC860) processor (revision 0×200) with 60416K/5120K bytes of memory

Self decompressing the image :
#######################

What is Rommon? it stand for ROM Monitor, we require to enter rommon to change the register number, when you enter rommon 1> follow above code in bold, type in confreg 2142, After that type in “reset” or reboot the cisco router, once reboot you are actually enter the router which the register number is 2142 you can just set the password exactly same with cisco router basic configuration step

Router>ena
Router#config t
Enter configuration commands, one per line. End with CNTL/Z.
Router(config)#ena password newpass
Router(config)#ena secret newsec
Router(config)#config-register ox2102
Router(config)#exit
Router#sh ver
Cisco IOS Software, 2800 Software (C2800NM-ADVIPSERVICESK9-M), Version 12.4(15)T1, RELEASE SOFTWARE (fc2)
Technical Support: http://www.cisco.com/techsupport
Copyright (c) 1986-2007 by Cisco Systems, Inc.
Compiled Wed 18-Jul-07 06:21 by pt_rel_team

ROM: System Bootstrap, Version 12.1(3r)T2, RELEASE SOFTWARE (fc1)
Copyright (c) 2000 by cisco Systems, Inc.

System returned to ROM by power-on
System image file is “c2800nm-advipservicesk9-mz.124-15.T1.bin”

This product contains cryptographic features and is subject to United
States and local country laws governing import, export, transfer and
use. Delivery of Cisco cryptographic products does not imply
third-party authority to import, export, distribute or use encryption.
Importers, exporters, distributors and users are responsible for
compliance with U.S. and local country laws. By using this product you
agree to comply with applicable laws and regulations. If you are unable
to comply with U.S. and local laws, return this product immediately.

A summary of U.S. laws governing Cisco cryptographic products may be found at:

http://www.cisco.com/wwl/export/crypto/tool/stqrg.html

If you require further assistance please contact us by sending email to
export@cisco.com.

cisco 2811 (MPC860) processor (revision 0×200) with 60416K/5120K bytes of memory
Processor board ID JAD05190MTZ (4292891495)
M860 processor: part number 0, mask 49
2 FastEthernet/IEEE 802.3 interface(s)
239K bytes of NVRAM.
62720K bytes of processor board System flash (Read/Write)

Configuration register is 0x2142 (will be 0×2102 at next reload)

Router#copy run start
Destination filename [startup-config]?
Building configuration…
[OK]
Router#reload

Reload mean reboot the router, after reboot the router, you can access with the new password already. This is how we reset cisco router password, some said hack cisco router login password , but this is the correct way to recover password for cisco router.

Few week back I face one confusion when one of our client require to increase their company computer from 200 to 1000′s PC, in the near future. They require to change the subnet mask in all their computer, server, and manageable switch. The client currently are using 255.255.255.0 for their subnet mask, and require to change it to 255.255.252.0. I have to assist them to change the setting in their 3Com manageable switches. I was confuse, why set to 252 instead of 255?

After Re-attend my CCNA class, CCNA in Penang, I understand how this work and also get the method on how to calculate subnet mask.

Normally for class C IP address, we will put the subnet mask as 255.255.255.0, but some other case, they are putting 255.255.255.128, 255.255.255.192, 255.255.255.224…. So when will use 128 or 192 or 225…. as your subnet mask?

For example, We use 128 (255.255.255.128), when we require not more then 126′s PC in the network.

Method to calculate subnet mask
For 255.255.255.128, Binary is 11111111.1111111.11111111.10000000, we categories this binary as ,

NetID: 1 (1′s One)

HostID: 7 (7′s Zero)

How many PCs:

Formula: 2^ HostID -2= PC s

How many PC: 2^7-2=126 PC

How many Network:

Formula: 2^NetID=Network

How many Network: 2^1=2

Below are the table on calculate subnet mask for:

255.255.255.128 (Max 126′s PC)

255.255.255.192 (Max 62′s PC)

255.255.255.224 (Max 30′s PC)

255.255.255. 240 (Max 14′s PC)

255.255.255. 248 (Max 6′s PC)

255.255.255. 252 (Max 2′s PC)

255.255.255. 254 (Serial subnet mask)

IT Engineer’s Life Experience
As above situation in my client side, they need 1000 PC’s, base on the formula above stated,

How many PCs:

Formula: 2^ HostID -2=number of PC

2^ ? =1024

2^10 =1024

HostID =10 (10′s zero)

The binary code for the subnet mask should be :

11111111.11111111.11111100.00000000

or we use 255.255.252.0 as the subnet mask in the network that we need 1000′s PC

Base on the above diagram, subnet mask quick reference, you are able to decide what is the subnet mask that suitable your company or your network need.

Example your computer require 4000′s PC, refer to the MAX HOST above, look for the 4096 Max Host, and the subnet mask are 255.255.240.0 without calculate subnet mask manually.

As above experience on my client side networking setting, now I know how to use suitable setting for the subnet mask in the future. Feel free to download the subnet mask quick reference and also copy down the above example on how to calculate subnet mask manually.

]]> http://www.icalvyn.com/calculate-subnet-mask-and-vlsm/feed/ 15 http://www.icalvyn.com/packet-tracer-video-tutorial-part-3/ http://www.icalvyn.com/packet-tracer-video-tutorial-part-3/#comments Mon, 24 Nov 2008 16:31:15 +0000 calvyn http://www.icalvyn.com/?p=722 After watch the Packet Tracer video tutorial about “What If” and “Visualization” on Packet Tracer Video Tutorial Part 1; also “Troubleshooting on Packet Tracer” and “Using Packet Tracer in Presentation” on Packet Tracer VIdeo Tutorial Part 2, this Part 3 video tutorial and also the last 2 tutorial on packet tracer that I am going to show you on:

Video Tutorial 5 - Guiding Student Configurations

At this chapter, the video tutorial guide the Cisco trainer/instructor to disable the physical and configuration tab (automatic mode), and only allow the student to use the command line to configure the cisco router in the cisco simulation software.

To disable this 2 tab (physical and configuration), just simply go to Option -> Preferences, go to Hide tab, tick the function you would like to hide, and also can go to administrative tab to key in password , and enable it, the password is to protect packet tracer software being changes by the student.

Video Tutorial 6 - Configuration Portability

This is the last packet tracer video tutorial that I going to shows, in this chapter, shows how we copy the real cisco product command line, and apply all this command over packet tracer by just copy and paste, or vice versa. Meaning that after you success configure the simulation router over the packet tracer, you are able to “show run”, copy down all the command line, and paste it into the real router without typing all the command over again.

This make me remember during I follow my senior over client side to configure cisco product, my senior use to have a pen drive, and all those cisco coding and command line are store in the notepad file. Once login to client’s cisco router, just copy the notepad, and paste in the hyper terminal, the command immediate apply after “copy run start” (save the setting)

Wanna to try this cisco simulation software? You can try to create a simple simulation with just a router, and try to put in the cisco router basic configuration. Once success the simulation, follow the “Configuration Portability” above, and paste the coding into your real cisco router. Happy learn on Cisco.