Jul 17 2008

Using FTP to upload an IOS image to a router

The ftp client in IOS will default to using the first username and password in the startup-config.  You therefore do not need to explicitly define an ftp username and password.  Make sure your FTP server is configured to accept the username and password configured on your router.

————————————————————————————-

conf t

username cisco password cisco

copy ftp: sup-bootdisk:

address or name of remote host []? 1.1.1.1

source filename []? s72033-ipservicesk9_wan-mz.122-18.SXF13.bin

destination filename [s72033-ipservicesk9_wan-mz.122-18.SXF13.bin]?

loading s72033-ipservicesk9_wan-mz.122-18.SXF13.bin !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

[OK - 80102916/4096 bytes]

————————————————————————————-

its probably not a good idea to use the above username and password:-)

By zismail • 12.2SX, 6509, FTP • 0 • Tags: , ,

Jul 3 2008

Add 802.11n to your existing network

Taken from Network World

By zismail • Wireless • 0 • Tags: , ,

Jul 3 2008

Lighting up a layer 2 trunk

I’ve seen this a number of times.  A user lights up a trunk and doesn’t restrict which VLANs can use the trunk, so Cisco IOS obviously allows all VLANs and this causes spanning tree to send a whole load of BPDUs to the remote device and if it has also been configured in a similar way at the remote end then spanning tree will then have to reconverge.  At this point you’ll probably have been kicked off the box and you’ll be sweating prefuously.  Hmm, not a good way to bring a trunk live.

The right way.

When you configure the port, make sure it is shut down.  Only bring it live (no shut) when you have configured both sides of the link and are sure that both sides have a compatible setup.  A good rule of thumb is to disallow ALL VLANs when you bring the trunk up.  Once the trunk is up, you can easily add more VLANs as and when required.

Heres a copy of a possible configuration you could use before you unshut the port.

interface GigabitEthernet1/1

switchport

switchport trunk encapsulation dot1q

switchport trunk allowed vlan none

switchport mode trunk

By zismail • Common Errors • 0 • Tags: , ,

Jul 3 2008

Etherchannel configurations – woops added the VLAN to the physical port.

Adding a VLAN to an Etherchannel

How many times have you heard that someone added a VLAN to a phyiscal layer2 interface instead of the logical layer2 port-channel and subsequently brought the etherchannel down.  If your lucky you might get away with it.  I’ve seen engineers take down entire data centers as well as call centers by issuing this command on the wrong interface.

For those of you who havent made this mistake, here is how to avoid it:-

Task: add vlan 20 to etherchannel 1.

The right way

conf t

interface port-channel 1

switchport trunk allowed vlan add 20

end

The wrong way

Do not add the VLAN to a port which is a member of the etherchannel.

ie

The command below will show the ports which are members of the etherchannel.

show etherchannel 1 summary

!

!

text removed

!

group     port-channel     protocol    ports

————————————–

1            po1(SU)              -               Gi5/3(P)    Gi5/4(P)

If you then look at the physical port, you can see it is a member of port-channel 1.

show run interface gi5/3

switchport

switchport trunk encapsulation dot1q

switchport trunk allowed vlan 10-19

switchport mode trunk

no ip address

channel-group 1 mode on

The last line ie channel-group 1 mode on indicates that this port is part of etherchannel 1.  If you try to add a VLAN to the etherchannel by adding the VLAN to the physical port, this port will be removed from the etherchannel and this will cause spanning tree to throw a wobbly.

Be warned:-)

By zismail • Common Errors • 0 • Tags:

Jul 2 2008

The Difference between 3G and 4G wireless

Taken from Network world

By zismail • Wireless • 1 • Tags: , ,

Jul 2 2008

Life after getting your CCIE

A few years after getting your CCIE (ie once you’ve recovered) you start wondering where to go next in your career. From my research there doesn’t seem to be an obvious next step. Some folks opt to go down the route of another CCIE, where as some decide to move into management.

I guess this is the point you have to ask yourself, which part of your job do you really enjoy. Here is a list of what I think are the main areas that a CCIE could be involved in. Id be interested to know if I’ve missed anything off the list.

1-Designing new networks based on proven technology.

2-Designing new networks based on unproven technology ie cutting edge stuff. these roles require a lot of perserverance. Early adopters especially need to be aware that cutting edge technologies can be full of bugs. Having an openmind in these situations can really help resolve issues. Whether you’re working for the vendor or end-user, these roles require a lot of energy and drive and the hunger to explore all possibilities. These roles can be very satisfying and rewarding and usually put you at the head of the game.

3-Product development ie stringing together various technologies to create products for service providers to sell. Similar to the above role, these roles can involve working with imature technologies but not always. These roles require good documentations skills, the ability to define flexible processes and usually the ability to train other members of staff how to provision that which you have developed.

4-Pre-sales – Usually requires a good high level understanding of technology, good visio skills, an understanding of the sales process and good presentation skills.

5-Post-sales -These roles require solid technical skills as well as the ability to train staff.

6-Advisory roles ie consultants – ie requires the ability to conduct a network analysis and advise an upgrade path.  Consultants need to be able to sift through the plethora of technological options available on the market and identify those with longevity as well as scalability and match them to funds available etc.

7-TAC – ie support roles- for those of us who like to dig deep.

8-Technical leads – usually require a good understanding of applications as well as network. These can be quite challenging roles. Leads need to be multi skilled who can clearly articulate current progress/issues to upper management, implement quaility controls to ensure consistency across the new rollout as well as oversee any technical issues which may arise.

9-Team leaders – these can vary depending on company – some Team leader roles are very non-technical.

10-Teaching – These roles require great communication skills as well as technical understanding.

11-Mentoring – can be very rewarding when you see others progress.

12-Architecture – A lot of these roles are hands off. These roles usually require a good understanding of hardware its limatations and ability to scale etc. These roles can be exciting but requires some good decision making skills.  if you’re going to recommend a company purchase 1000 Cisco 3750 switches for a local loop unbundling project, then you’d better be sure you’re you’ve got the right features, port densities and back plane speeds.

Im sure there are more roles out there for CCIEs.

comments welcome

By zismail • CCIE • 0 • Tags: