Wednesday, 21 December 2011

Quick Cisco Switch and Router Troubleshooting

Haye.. !! some helpful quick troubleshooting commans

show run sec class-map
show run sec policy-map
sh run sec router
sh run sec crypto
sh run inc ip access-group
sh run inc ip local
sh run inc ip policy
sh run inc service-policy
sh run inc ip access-group
sh run inc vlan filter

Friday, 16 December 2011

Cisco and HP Procurve Trunk 802.1Q

This post only discusses how to configure an 802.1q VLAN trunk between a Cisco switch and an HP ProCurve switch. In this test I am using Cisco 3560 and HP ProCurve 2910 AL over here trunking refer to an 802.1q tagged VLAN trunk. Don’t get confused in Procurve world trunking refers to a feature like ether channel in Cisco world.

Mind that ISL trunk will not work between Cisco and HP because it is Cisco proprietary protocol. The trunk between a Cisco and HP Procurve switch must be 802.1q I rarely see ISL in use these days, and I personally consider 802.1q the preferred method of encapsulation if for no other reason than its interoperability.

Once you have configured all of the required VLANs (I hope I don’t need to explain how to configure VLANS) now configure the trunk on the Cisco switch in fa0/48 is our trunk port connected to HP ProCurve using the following commands:

Cisco3560(config)# interface fa0/48
Cisco3560(config-if)#switchport mode trunk
Cisco3560(config-if)# switchport trunk allow vlan 1,2,3
Cisco3560(config-if)#no shut

In this example I am using three VLANS Vlan 1 , 2, and 3
Here interface Fa0/48 is the trunk port on the Cisco switch.

Procurve switches, can have a VLAN either tagged or untagged on any particular port as shown in the configuration below.

HP2910al(config)#vlan 2
HP2910al(Vlan-2)#tagged 48

Now we have enabled trunk interface between HP and Cisco for Vlan 2 only, trunk will not carry any traffic a part from Vlan 2 in order to allow Vlan 3 traffic on Trunk we need to setup port 48 in HP switch as tagged port for Vlan 3 (Clear as MUD.. !!!!)

HP2910al(config)#vlan 3
HP2910al(Vlan-2)#tagged 48

Key point you have to setup uplink port 48 in our case on HP as tagged port for all the vlan that will pass through the trunk.

Now test connectivity between two hosts that are in the same VLAN i.e Vlan 2 , but on different switches. As you have learnt, configuration of 802.1q trunks between Cisco and HP Procurve switches is not a rocket science . if its not working double check the config and every thing should be fine.

Thursday, 15 December 2011

HP and Cisco commands Reference

Hi Everyone , forget about the fight which one is the better technology every product have its on Pros and Cons .
I am sharing here some terminologies and command differences , I hope they would be helpful

HP aggregated interfaces are called trunks and Cisco it is EtherChannel.

The confusion arises because term trunk is used differently in Cisco and HP. In Cisco trunk is an interface that is configured to support 802.1Q (VLAN). which is configured to support multiple VLANs is called a trunk however in HP Prociurve operating system, an interface that supports multiple VLANs is tagged.

Remeber these guidelines

An “access port” on Cisco is an “untagged port” on HP ProCurve.
A “trunk port” on Cisco is a “tagged port” on HP ProCurve.
A “port channel” on Cisco is called a “trunk” on HP ProCurve.
A Cisco "Access port" is "untagged" in HP Procurve

Trunking from the ProCurve side is meant to aggregate multiple ports together, while on Cisco it is meant to transport multiple VLANs over one port.

Link aggregation on the Cisco side is called “channeling"

*****Some main Hints and Tips******

Pay attention to multi-VLAN ports.
Make sure that the native VLAN on the Cisco trunk is the untagged VLAN on the ProCurve tagged port.
Ensure that the same VLANs are allowed and configured on both sides.
Remember that, unlike with Cisco, BPDUs (spanning tree, LLDP, and LACP) are not attached to the untagged port or any VLAN on HP ProCurve

To combine Cisco and HP ProCurve spanning tree networks, MSTP can be run on the Cisco devices, or PVST Cisco networks can be combined with MSTP HP ProCurve networks, I am running PVST on Cisco network and I added couple of HP Procurves with RSTP and didn't caused any problem, make sure you modify the priority at HP or cisco as per requirement.

Cisco supports Hot Standby Router Protocol (HSRP), and HP ProCurve supports Virtual Router Redundancy Protocol (VRRP), during migration ensure that both cores are from the same
vendor, whether HP ProCurve or Cisco. If you replace one core, replace the other at the same time.

Finally Routing Protocol HP doesn't support Cisco proprietary routing protocols.

There are some minor differences to consider between the two different OSPF implementations:

  • Cisco OSPF is enabled with network statements globally.

  • HP ProCurve OSPF is enabled within the VLAN context.

  • There are redistribution differences.

  • HP ProCurve is always non-broadcast multiple access (NBMA).

  • Cisco uses the highest loopback IP address for router ID, while HP ProCurve devices typically use the lowest.

  • With HP ProCurve, the loopback is always /32 mask.

  • With HP ProCurve, the OSPF link cost is “1” by default.

Tuesday, 6 December 2011

Toughest Job interview Questions

I and my friends have recently gone though some interviews processes, last night we thought to share our experience to help others.

Below are top tough interview questions that you may face, there is no obvious right answers that is aimed to highlight your abilities and strengths.

1. Describe your self.

It is definitely not an invitation to give your life history they are not interested in this. You should aim to describe the kind of person you are in a couple of minutes at most. Concentrate on positive qualities, and link them to the key responsibilities of the job you're applying for.

2.What do you enjoy most in your current job?

It is tricky question he actually wants to know what you don’t link in this job. The key is that you like everything about your job. Pick some part of current job that matches new job for which you are interviewed fro.

3. What do you feel you can bring to this job?

This is another question that gives you a chance to shine. You need to link your past experience or skills to the requirements of the job. Pick up to three key strong points in your favour that are relevant to this job.

4. What is your biggest weakness?

Huummm!!! it is hard and very easy at the same time depending if you are prepared for it or not, I always answer 'I'm useless at getting round to household jobs - changing light bulbs and fixing leaky taps. Avoid giving any weakness like I don’t like taking OrdersJ. Then why you are here start your own business.

5. What is your goal or what you want to do in next 5 years time?

Explain your career aligned with the role you are applying for, don’t tell about your dreams :)

6. Why you think you are the right Candidate for the role? Being on harsh end it can be asked as Convince me to hire you.

This question need some preparation and company research, interviewer is looking for any one candidate who have same goals as the company have.

7. Tell me about how you work as part of a team?

Employer want to know how well you work as a part of team , explain you can work on your own or with any one else , you are a self starter , good time management skills .