Network technologies and trends


January 6, 2009  6:11 AM

Cisco Etherchannel Overview and how it can be configured in Cisco Catalyst Switches – Series 6

Yasir Irfan Yasir Irfan Profile: Yasir Irfan

In the previous five posts I was talking about the Etherchannel  , types of protocols used , rules and restrictions applied to an Etherchannel  . Now it’s the time to see how an Etherchannel   can be configured in a Cisco Catalyst Switch.

An Etherchannel in a Cisco IOS can be defined as Layer 2 Etherchannel or a Layer 3 Etherchannel.

For a Layer 2 Etherchannel, physical ports are placed into an Etherchannel group.

For a Layer 3 Etherchannel, layer 3 SVI (Switch Virtual Interface) is created, and then the physical ports are placed into an Etherchannel group which is bound to the L3 SVI.

 

Now let’s see how to configure a Configure a Layer 2 Etherchannel in a Cisco Catalyst Switch using a PAGP (port aggregation protocol) Protocol. In my previous posts I did discussed about the PAGP protocol, it’s a Cisco proprietary protocol, can be applied only in Cisco Catalyst Switches.

Here is the scenario which we will follow

From the above diagram we have two Cisco 3560 Catalyst Switches named ITKESW01 and ITKESW02.

We will configure a Layer 2 Etherchannel between the Cisco 3560 Catalyst Switches  ITKESW01 and ITKESW02. The  Giga Ethernet ports 0/45, 0/46/,0/47 & 0/48 on a Cisco 3560 Catalyst Switches  ITKESW01 are trunk ports  and they are connected to Giga Ethernet ports 0/1,0/2,0/3 and 0/4 (also trunk ports) in Cisco 3560 Catalyst Switch  ITKESW02.

 

The configuration is as follows

 

Configuration in the Cisco 3560 Catalyst Switch  ITKESW01

 

First run the command “Show interfaces trunk

 

ITKESW01#sho interfaces trunk

 

Port        Mode             Encapsulation  Status        Native vlan

Gi0/45      on                        802.1q         trunking            1

Gi0/46      on                        802.1q         trunking            1

Gi0/47      on                        802.1q         trunking            1

Gi0/48      on                        802.1q         trunking            1

 

Port        Vlans allowed on trunk

Gi0/45        1-4094

Gi0/46        1-4094

Gi0/47        1-4094

Gi0/48        1-4094

 

Port        Vlans allowed and active in management domain

Gi0/45        1

Gi0/46        1

Gi0/47        1

Gi0/48        1

 

Port        Vlans in spanning tree forwarding state and not pruned

Gi0/45       1

Gi0/46       1

Gi0/47       1

Gi0/48       1

 

ITKESW01#

 

Second Step configure the Giga Ethernet ports 0/45 to 0/48 in the Etherchannel

 

ITKESW01#config t

ITKESW01(config)# interface range gigabitEthernet 0/45 – 48

ITKESW01(config-if-range)#channel-protocol pagp

 

Note: PAgP protocol is configured to be used in this channel

 

ITKESW01 (config-if-range)# channel-group 1 mode desirable

Note: A logical port-channel interface is automatically created when ports are grouped into a channel group.

Configure the mode desirable to be used in PAgP 

 

Configuration in the Cisco 3560 Catalyst Switch  ITKESW02

 

 

ITKESW02#sho interfaces trunk

 

Port        Mode             Encapsulation  Status        Native vlan

Gi0/1      on                        802.1q         trunking            1

Gi0/2      on                        802.1q         trunking            1

Gi0/3      on                        802.1q         trunking            1

Gi0/4      on                        802.1q         trunking            1

 

 

Port        Vlans allowed on trunk

Gi0/1        1-4094

Gi0/2        1-4094

Gi0/3        1-4094

Gi0/4        1-4094

 

 

Port        Vlans allowed and active in management domain

Gi0/1        1

Gi0/2        1

Gi0/3        1

Gi0/4        1

 

 

Port        Vlans in spanning tree forwarding state and not pruned

Gi0/1       1

Gi0/2       1

Gi0/3       1

Gi0/4       1

 

ITKESW02#

 

Second Step configure the Giga Ethernet ports 0/1 to 0/4 in the Etherchannel

 

ITKESW02#config t

ITKESW02(config)# interface range gigabitEthernet 0/1 – 4

ITKESW02(config-if-range)#channel-protocol pagp

 

Note: PAgP protocol is configured to be used in this channel

 

ITKESW02 (config-if-range)# channel-group 1 mode auto

Note: A logical port-channel interface is automatically created when ports are grouped into a channel group.

Configure the mode auto to be used in PAgP 

Now run show command to display the Etherchannel configurations on the Cisco 3560 Catalyst Switches  ITKESW01 and ITKESW02

ITKESW01#sho etherchannel 1 summary

Flags:  D – down        P – in port-channel

        I – stand-alone s – suspended

        H – Hot-standby (LACP only)

        R – Layer3      S – Layer2

        u – unsuitable for bundling

        U – in use      f – failed to allocate aggregator

        d – default port

 

Number of channel-groups in use: 1

Number of aggregators:           1

 

Group  Port-channel  Protocol    Ports

——+————-+———–+———————————————–

1      Po1(SD)          PAgP      Gi0/45 (P)   Gi0/46 (P)  Gi0/47 (P)  Gi0/48 (P)  

ITKESW01#

 

ITKESW02#sho etherchannel 1 summary

Flags:  D – down        P – in port-channel

        I – stand-alone s – suspended

        H – Hot-standby (LACP only)

        R – Layer3      S – Layer2

        u – unsuitable for bundling

        U – in use      f – failed to allocate aggregator

        d – default port

 

Number of channel-groups in use: 1

Number of aggregators:           1

 

Group  Port-channel  Protocol    Ports

——+————-+———–+———————————————–

1      Po1(SD)          PAgP      Gi0/1 (P)   Gi0/2 (P)  Gi0/3 (P)  Gi0/4 (P)  

ITKESW02#

 

In upcoming posts I will show how to configure a Layer 2 Etherchannel  using LACP protocol

January 3, 2009  6:47 AM

Cisco Etherchannel Overview and how it can be configured in Cisco Catalyst Switches – Series 5

Yasir Irfan Yasir Irfan Profile: Yasir Irfan

Dear Friends,

 Hope it’s going to be a good beginning in the year 2009 and lest hope to see the peace and harmony all over the world.

Now let’s see what options are available for load balancing in an Etherchannel  bundle.  How does the Cisco Catalyst Switch determines which physical link in the Etherchannel  bundle to use to forward the data?

The answer is the Cisco Catalyst Switch uses a polymorphic algorithm taking key fields from the header of the packet to generate a hash to a physical link in the Etherchannel group.

Data sent across an Etherchannel is not load-balanced equally between all interfaces. Etherchannel  utilizes a load-balancing algorithm, which can be based on several forms of criteria, including:


December 29, 2008  8:00 AM

Cisco Etherchannel Overview and how it can be configured in Cisco Catalyst Switches – Series 4

Yasir Irfan Yasir Irfan Profile: Yasir Irfan

Automating and Creating of an Etherchannel.

The automate creation of an Etherchannels group can occur only when the Cisco Switches are running same Etherchannel protocols. Using different Etherchannel protocols at each end will not work. One more important criterion for the automated creation of the Etherchannel  is the links must share the similar physical characteristics.   etherchannel4

Configuration of ports into an Etherchannel  are based on pre defined Etherchannel  modes that are assigned as a default or modified via user configuration to an Ethernet port. There are five Etherchannel modes, which can be used for automated creation of an Etherchannel  .

etherchannel5


December 28, 2008  11:16 AM

Here is the great opportunity to attend virtually the Cisco News Conference at CES 2009

Yasir Irfan Yasir Irfan Profile: Yasir Irfan

Dear Friends what a gift from Cisco Systems to its lovers for the New Year 09. Cisco will unveil new consumer products and initiatives during a news conference at the 2009 International Consumer Electronics Show (CES) in Las Vegas Convention Center on January 7, 2009.

CES Banner Courtesy: Cisco SystemsThe key personalities who are expected to join the stage with the Cisco Chairman and CEO John Chambers are his team of team of senior executives. They are expected to discuss how Cisco is enabling the connected life through a new class of compelling communication and entertainment experiences that are more visual, more social and more personal. The press conference will be webcast live for those unable to attend in person.

Register to Receive Cisco at CES 2009 Text Messages

[kml_flashembed movie="http://www.youtube.com/v/7AtOEsnPhMY" width="425" height="350" wmode="transparent" /]

Stay current with what Cisco is doing at CES 2009. Receive video messages and speaker updates both preshow and onsite. Get a text message as soon as new content is posted.Register from your personal computer by going to www.cisco.com/alerts and clicking the text messing registration and manager link. You can register directly from your cell phone by texting to our number 24726 (spells Cisco on your phone keypad) with the word CES in the body of the message.


December 27, 2008  6:19 AM

Cisco Etherchannel Overview and how it can be configured in Cisco Catalyst Switches – Series 3

Yasir Irfan Yasir Irfan Profile: Yasir Irfan

Dear Friends, hope everyone is having great holidays, have fun. In my previous post  I was focusing on some of the limitations of Etherchannel. Now let’s proceed a step ahead and figure out about the Etherchannel negotiation protocols. Etherchannels can be negotiated between two Cisco Catalyst Switches  to provide some dynamic link configuration.

 Basically there are two types of protocols are available, which can be used to bundled the automated creation of an Etherchannel in the Cisco Catalyst Switches.

Etherchannel3

In upcomming post I will try to concentrate on automating the creation of an Etherchannel . Have fun and happy new year 2009.


December 24, 2008  12:07 PM

90% of email is spam according to Cisco Annual Security report 2008

Yasir Irfan Yasir Irfan Profile: Yasir Irfan

According to the Cisco Annual Security Report 2008, Spam accounts nearly 200 billion messages per day or approximately 90% of all email worldwide. 

The report highlights the security threats and trends; the most disturbing fact is more online criminals are using real email accounts with legitimate web mail providers to bombard the emails with spam. This method, known as ‘reputation hijacking’, makes spam harder to detect and block.

According to Cisco estimates, spam resulting from email reputation hijacking of the top three web mail providers accounted for less than 1% of all spam worldwide, but made up 7.6% of the providers’ mail traffic.

Additionally, researchers have seen a 90% growth in threats originating from legitimate domains, doubling 2007 figures. For rest of the story please check the article published by ITP Middle East.


December 20, 2008  6:33 AM

Cisco Etherchannel Overview and how it can be configured in Cisco Catalyst Switches – Series 2

Yasir Irfan Yasir Irfan Profile: Yasir Irfan

Dear Friends, in my previous post I just introduced Etherchannel, now let’s proceed one step ahead,  there are certain limits with the Etherchannel  lets figure out what are those  limits,

Etherchannel2

 

·         An Etherchannel  Group Number must be in the range of 1 to 256.

·         All ports in the target Etherchannel  group MUST be in the same VLAN.

·         If one physical link in the Etherchannel  group is a TRUNK, then all other ports must be configured as trunks carrying the same VLAN information.

·         Any defined broadcast limits must be the same across all ports in an Etherchannel.

·         An LACP Etherchannel  group cannot support any physical links in half duplex mode.

·         No port in the Etherchannel  group can be defined as a SPAN port.


December 17, 2008  5:41 AM

Serious security flaw found in Internet Explorer

Yasir Irfan Yasir Irfan Profile: Yasir Irfan

Dear Friends users of Microsoft’s Internet Explorer are being advised by experts to switch to a rival until a serious security flaw has been fixed.

The flaw in Microsoft’s Internet Explorer could allow criminals to take control of people’s computers and steal their passwords, internet experts say.

According to CNET news  Microsoft issued a critical security warning Tuesday that a malicious exploit is making the rounds and attacking vulnerabilities in Internet Explorer 7.

The risk is believed to be widespread, given that IE 7 is the latest version of Microsoft’s browser and is bundled with XP service pack 3 and also Vista, said Dave Marcus, director of security research and communications for McAfee’s Avert Labs.

The AZN Trojan, which has been making the rounds since the first week of December, has the potential of infecting users’ system with a Trojan horse, or “downloaders” that can download other forms of malware onto a user’s system.

Please acces the complete article  at CNET  website.


December 15, 2008  6:55 AM

Cisco Etherchannel Overview and how it can be configured in Cisco Catalyst Switches – Series 1

Yasir Irfan Yasir Irfan Profile: Yasir Irfan

Dear Friends in this upcoming series of posts I would like to concentrate on Etherchannel , what is Etherchannel? , what rules and restrictions are  applied to an Etherchannel and finally I will show you how to configure an Etherchannel in Cisco Switches both layer 2 as well as layer 3.

 

An Etherchannel combines multiple physical links into a single logical link that provides aggregate bandwidth of 800 MBPS (fast Etherchannel, full duplex) , 8 GBPS (Giga Etherchannel) or 80 Gbps (10 Giga Ethernet) . Ideal for load sharing or link redundancy – can be used by both layer 2 and Layer 3 subsystems and Etherchannel  can provide network managers with a reliable, high-speed solution for the campus network backbone. EtherChannel technology was invented by Kalpana in the early 1990s. They were later acquired by Cisco Systems in 1994. In 2000 the IEEE passed 802.3ad which is an open standard version of EtherChannel.

I would like to explain some key points about Etherchannel using graphical diagrams so that it’s easy understand and to remember.

Etherchannel1

 

Etherchannel  can be configured defined on Ethernet, Fast Ethernet, Giga Ethernet or 10 Giga Ethernet ports.


December 14, 2008  7:04 AM

Cisco Systems announces CCIE Wireless Certification

Yasir Irfan Yasir Irfan Profile: Yasir Irfan

Dear Friends Cisco Systems has announced the availably of CCIE Wireless Certification and it’s confirmed. So what are waiting for, you can start planning for the prestigious CCIE Wireless Certification, again Cisco proves they are concerned about the latest technological developments in the field of networking. Please do check a great article about CCIE Wireless Certification from Search Networking.Beta candidate registration should begin this fall, along with a blueprint release. Beginning early 2009 the Wireless CCIE beta testing will begin! As of now, topics of the test are expected to cover all aspects of wireless from design through implementation including the implications of security, routing and switching and voice technologies. Check back often for any additional information!Cisco CCIE Wireless Certification
The Cisco CCIE Wireless certification assesses and validates wireless expertise. Candidates who pass the CCIE Wireless certification exams demonstrate broad theoretical knowledge of wireless networking and a solid understanding of wireless local area networking (WLAN) technologies from Cisco, the market leader in WLAN technology.Benefits of CCIE Certified Wireless Certification

  • Greater opportunity for salary increase and job advancement in wireless networking industry
  • Validates expertise in major aspects of WLAN technology
  • Provides next step for individuals interested in a career in managing or working with Cisco wireless technologies

The written exam for CCIE Wireless will be made available through Pearson VUE on February 17th, 2009. The lab exam for CCIE Wireless will be made available in April 2009. To find out more about the CCIE Wireless Certification and access the latest blueprints and study materials, visit the Cisco Learning Network.


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