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IP prefix-list ip prefix-list provides the most powerful prefix based filtering mechanism Here is a quick little tutorial on Prefix-lists for you. A normal access-list CANNOT check the subnet mask of a network. It can only check bits to make sure they match, nothing more. A prefix-list has an advantage over an access-list in that it CAN check BOTH bits and subnet mask - both would have to match for the network to be either permitted or denied. For checking bits a prefix list ALWAYS goes from left to right and CANNOT skip any bits. A basic example would be this: 172.16.8.0/24 If there is only a / after the network (no le or ge) then the number after the / is BOTH bits checked and subnet mask. So in this case it will check the 24 bits from left to right (won't care about the last 8 bits) AND it will make sure that it has a 24 bit mask. BOTH the 24 bits checked and the 24 bit subnet mask must match for the network to be permitted or denied. No we can do a range of subn...

LSA types allowed per area type. Area Type 1&2 3 4 5 7 Backbone (area 0) Yes Yes Yes Yes No Non-backbone, non-stub Yes Yes Yes Yes No Stub Yes Yes No No No Totally stubby Yes No [*] No No No Not-so-stubby Yes Yes Yes No Yes

You need to remember how an access list wildcard mask works. 192.168.1.0 0.0.0.255 Where you have a 0 bit in the wildcard then the corresponding bit within the IP Address must match. So in the example above 192.168.1 must match. Where you have a 1 bit then the Wildcard mask does not care about the corresponding bit within IP address (also known as the 'don't care bit), thus the 255 in the last octect means that the corresponding bit within the IP address can be anything between 1 and 255. Therefore when matching routes with an access list, the access list would let through 'Prefixes' from: 192.168.1.0 to 192.168.1.255 Obviously within this range there would be no routes that are advertised as routes from a routing protocol (like broadcast), however it does capture everything. A Prefix list is far more precise 192.168.1.0/24 will only let through 192.168.1.0, if you wanted the prefix list to act like the access list, you would use the ge and le statements at th...

"match precedence" will match both ipv4 and ipv6. "match ip precedence" will match on only ipv4. http://www.cisco.com/en/US /docs/ios/12_3t/qos/command /reference/qos_m1gt.html #wp1112521

if you want to use udld on copper ports, udld aggressive is your only option. Notes: If you use udld enable global config this will enable udld for fibre ports only If you use udld aggregssive global config command this will enable aggressive udld for fibre ports but won't enable udld on copper ports. To enable udld for copper ports, you manually need to go onto that port and enable using 'udld aggress'.

Brian McGahan to Herbert , slevin , Cisco show details 8/22/07 Reply Also keep in mind that in a regular NSSA the ABR does not originate a default route automatically. With the stub , totally-stubby, and not-so-totally-stubby areas the ABR does automatically originate a default route. This means without additional configuration all devices in the NSSA will lose connectivity to external OSPF routes that are originated in other areas, unless they already have an alternate route to them aside from a route via the ABR.

OSPF Not-So-Stubby Area (NSSA) Downloads OSPF Not-So-Stubby Area (NSSA) Document ID: 6208 Author: Syed Faraz Shamim Contents Introduction Prerequisites Requirements Components Used Conventions What Is a Type 7 LSA? Configuration Tasks Defining a Not-So-Stubby Area Defining an NSSA Totally Stub Area Filtering in NSSA Default Route in NSSA Default Summary Route Default Type 7 NetPro Discussion Forums - Featured Conversations Related Information Introduction The OSPF not-so-stubby area (NSSA) feature is described by RFC 1587 and is first introduced in Cisco IOS ® Software release 11.2. It is a non-proprietary extension of the existing stub area feature that allows the injection of external routes in a limited fashion into the stub area. This document explains how the NSSA feature works. Redistribution into an NSSA area creates a special type of link-state advertisement (LSA) known as type 7, ...

IP Routing How Does OSPF Generate Default Routes? Document ID: 13692 Contents Introduction Before You Begin Conventions Prerequisites Components Used Types of OSPF Areas Normal Areas Stub and Totally Stub Areas NSSAs Related Information Introduction The way that Open Shortest Path First (OSPF) generates and advertises default routes (0.0.0.0) varies depending on the type of area the default route is being injected into. In this document, we cover normal areas, stub/totally stub areas and not-so-stubby areas (NSSAs). Before You Begin Conventions For more information on document conventions, refer to the Cisco Technical Tips Conventions . Prerequisites There are no specific prerequisites for this document. Components Used This document is not restricted to specific software and hardware versions. Types of OSPF Areas Normal Areas: These areas can either be standard areas or transit (backbone) areas. Standard areas are defined as ...

Using multiple IPBlue Phones on one PC The IPBlue phones are very handy for the vmware/dynamips simulated voice lab. However, the problem is that when you start up a second instance, it defaults to the first MAC address available and the first and second instances start flapping trying to re-register to the call manager using the same MAC address. Here is a quick and 'not so dirty' solution: The phone basically reads its configuration from the windows registry when started. The trick is to make sure the appropriate MAC address is in the registry (assuming you have 2 or 3 NICs or Virtual vmnet interfaces in case of VMware) before you start the application each time. The settings are stored under HKEY_CURRENT_USER\Software\IPblue\ in the registry. Follow the procedure below to create multiple phone 'profiles' first Launch the IPblue phone Choose one of the available MAC addresses. Make sure settings on CCM / CCME is set correc...

 

 

 

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RESUME Name : Usman Ali Nationality : Pakistani Date of birth : 12/04/1973 Languages : English, Urdu and Arabic Contact : usman198@yahoo.com Mobile: 0092 333 4857766 Education BCS (Bachelor of Computer Sciences) 1996 Certifications Cisco certified network associate CCNA 2.0. Cisco Certified Network Professional CCNP. Cisco Sales Essentials CSE (646-201) MCSE (Microsoft certified system engi...

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