Cisco Tips & Tricks

October 27, 2008

Compute an access-list to match even or odd networks

Filed under: Access-lists, ccie, IP Routing, Router, security, Technology and Software — ciscotips @ 10:16 pm

One of my old student who is preparing for CCNP asked me on how to write an access-list for permitting/denying even or odd networks. So I am just pasting my email reply to him

Here is a simple tip to write an access-list for even or odd networks.

Lets say we are asked to permit all odd or permit all even for 192.168.1.0/24 ?

We’ll play the game with last octet or I should say the least significant bit of last octet.

-If it is 0, the IP address will be Even

-If it is 1, the IP address will be Odd 

192.168.1.00000001 = 192.168.1.1 – odd

192.168.1.00000011 = 192.168.1.3  – odd

192.168.1.00000010 = 192.168.1.2   even

192.168.1.00000100 = 192.168.1.4   even

FOR Even Networks

The IP address will be 192.168.1.0

With the wild card mask as 0.0.0.254

254 = 11111110

Here, 0 means DO CARE of the last bit in IP address (must be ZERO)

Hence ACL will be

access-list 1 permit 192.168.1.0  0.0.0.254

For Odd Networks

The IP address will be 192.168.1.1

With the wild card mask as 0.0.0.254

254 = 11111110

Here, 0 means DO CARE of the last bit in IP address (must be ONE)

Hence ACL will be

access-list 1 permit 192.168.1.1 0.0.0.254
 

  

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October 24, 2008

Day 3, 4 and 5 of Narbik’s Bootcamp

Filed under: bgp, ccie, IP Routing, QOS, Technology and Software — ciscotips @ 6:22 pm

Sorry for posting late, Narbiks bootcamp was fun. Its worth attending his bootcamp if you are somewhere in the mid-tier of your CCIE preparation. Narbik recommends to cover Soups-to-nuts before you attend his bootcamp and he is right., otherwise it can be too much of information for you in 5 Days. Here is what he covered in last three days.

Day 3:- BGP

It was a big day for me. Day 3 is a BGP day, youy have  almost 200 pages worth of BGP labs. Narbik’s BGP  lecture style is totally different then the conventional CCIE Instructors. He doesn’t start BGP with Attributes or BGP states. He attacks on BGP optimization and then buiold you towards attributes and other advance topics. Simply awesome. He will start with MSS ( Maximum segment size) , Scan time, Advertising Interval and then take you to Memory pools, templates and Peer-groups. At last he will talk about BGP states, Aggregation, Attributes and some awesome route-filtering techniques. I will say that was my best BGP class.

Day 4:- RIPv2 and QoS

Another big day which was dedicated to Qos and 2 hours worth of lecture for RIP v2.  He showed what RIPv2 is worth of. People normally ignore RIP but if you know what all you can do with RIP. You will never be disappointed to use it for your small size network. He covered optimization, RIP updates,Filtering,redistribution,authentication  building it on some advanced scenarios.

Qos:- Qos

Qos was never my strong topic, although I am using it regularly in my job but I always struggled on few advanced topics. I should not have a problem in Qos after attending Narbik’s lecture.  Narbik started Qos with Queuing. He covered, CBWFQ, LLQ, filtering,CBWRED,Shaping, CAR,policing and SRR. Pretty good lecture indeed!

FInal Day ( Day 5 Multicast and CCIE lab tips).

Narbik covered multicast Addressing, Delievery Methods, Manipulating MCast Traffic, Dense,sparse modes, MSDP,ANycast and udp helper. I still have to work on Multicast labs but I am sure  I can practice on it  and grasp what I need most for my Lab.

As I am going through Narbik’s Advance 6 volume CCIE workbooks, I will try to post tips and tricks on various technologies going forward.

October 17, 2008

Mobile CCIE Routing and Switching Labs

Filed under: ccie — ciscotips @ 9:08 am

Cisco has introduced the mobile lab program to provide candidates greater access to Lab testing while greatly reducing travel time and expenses. Mobile CCIE Labs provide a convenient and cost-effective method for candidates to test for CCIE Routing and Switching in areas which do not have permanent lab locations.

The Mobile CCIE Lab reduces the need for costly travel, hotel, passport, and visa fees, missed days of work and the need to leave the country to take the CCIE Lab exam.

Scheduled Mobile Lab Location: Scheduled Dates:
Karachi, Pakistan Oct 13-17
Cairo, Egypt Oct 26-30
Istanbul, Turkey Nov 3-7
Johannesburg, South Africa Nov 24-28

 

Map of Cisco Lab Locations and proposed Mobile Labs

 

Proposed Mobile Lab Locations: Proposed Dates:
Seoul, Korea Dec ’08
Kuala Lumpur, Malaysia Jan‘09
Shanghai, China Jan‘09
Moscow, Russia Jan, Apr, Jul, Sep ‘09
Riyadh, Saudi Arabia Mar ‘09
Belgrade, Serbi Mar‘09
Kiev, Ukraine Mar & Apr‘09
Osaka, Japan Apr & Jul‘09
New Delhi, India May ‘09
Jakarta, Indonesia May‘09
Chi Min City, Vietnam Jun ‘09
Johannesburg, South Africa Jun ‘09
Amman, Jordan Aug ‘09
Mexico City, Mexico Aug ‘09
Singapore Aug ‘09

October 15, 2008

Narbik’s Bootcamp Day-2

Filed under: Router — ciscotips @ 4:40 pm

The day started with excellent humor from Narbik 🙂 and then he grilled all of us with OSPF. I must say Now I know why I scored so less in my IGP. Here is what he covered in his OSPF and EIGRP class.

-RID,Areas
-LSA’s
-Adjacency
-N/w Types
-Fast neighbor down detection
-DB overload protection
-Authentication
-Filtering
-Summary
-Area Types

Guys trust me, It just opened my eyes wide. It was not just overview. I simply loved it!

Here are the EIGRP topics we covered
-Update
-Passive-interface
-Summary
-default route
-Authentication
-Metric
-Stub

Last but not least, excellent workbook and bootcamp labs.

October 14, 2008

Narbik’s Bootcamp Day-1

Filed under: ccie, IP Routing, Router — ciscotips @ 7:35 pm

This is my first ever training class of Cisco. I never knew what to expect. Most of the guys have either attended boot-camps from other vendors or have attended other cisco classes in the past. For me its all for the first time. Without bragging I must say Narbik class is full of tips and tricks 🙂 . People say no to experiments AND do exactly what is specified in doc cd but Narbik is different. He recommendsless commands to accomplish the task. Simply do what is meaningful. Don’t do things which doesn’t mean anything?

The first day was 60-70% hands on as Narbik handed us 5 volumes of Advance CCIE R&S workbook. and a seperate bootcamp workbook. First day we did basic switching hands on and then Narbik went through Security topics ( Theory/White board… no slides/projectors). Here is the list

Vlan Mapping
MAC Floding
DHCP snooping
IP source-guard
DAI
MAC ACL’s
VLAN ACL’s
Private VLan’s

And some Great Tips on FR, which I’ll probably share in my later posts.

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