CCIE Wireless Multicast Best Practices

Here are some best practices for multicast with wireless.

First thing make sure multicast is enabled on the switch:

• Switch(config)#ip multicast-routing distributed

There are two flavors of multicast dense mode or sparse mode.  Dense mode is a push and prune method where you just enable multicast on which interfaces you want to participate and all of those interfaces are pushed the multicast stream.  If you want to enable that use the command:

• Switch(config-if)#interface vlan 100
• Switch(config-if)#ip pim dense-mode

Most people use sparse mode and this is most likely what you will see on the exam.  With pim-sparse mode you need a rendezvous point where all the multicast is directed where you can joing the multicast group.  There are different ways to configure this but for the interfaces to use multicast you use the commands:
  

• Switch(config-if)#interface loopback 0
• Switch(config-if)#ip pim sparse-mode 

To create a rendezvous point you use the following command:

• Switch(config)#ip pim rp-address 10.10.10.10

Most users use a loopback address as the rendezvous point.  You can also add access-lists after that command with the access-list number to limit what groups can join or deny.

You can also use Auto-RP so instead of using a static rendezvous point, a router can advertise itself as a RP.  You need a RP mapping agent to listen to other routers RP's to decide which should be the RP.  
You can use the following command:

• Switch(config)#ip pim send-rp-announce loopback 0 scope 6 group-list 1
• Switch(config)#ip pim send-rp-discovery loopback 0 scope 6

The scope means how many hops you want to announcement goes. In this example it is 6 hops.  The group list is an access-list for what multicast groups can join this rendezvous point. 

  

Wireless QoS Best Practices

QoS the necessary evil of CCIE Wireless.

1. Best practices are to trust CoS on trunk ports and DSCP on access ports.

2.  Make sure QoS is turned on the switch by the command:

     Switch#show mls qos

     Switch#conf t

     Switch(config)# mls qos

     Switch(config)#interface g0/1
   
     Switch(config-if)# mls qos trust cos

     Switch(config)#interface g0/2
   
     Switch(config-if)# mls qos trust dscp

3.  Cisco Controllers do not know how to map the DSCP to CoS to match what the switch has so you have to map the correct DSCP to CoS value and Cos to DSCP values. The first command provides the the CoS to DSCP map, and the next two are for the DSCP to CoS maps. 

     Switch(config)#mls qos map cos-dscp 0 8 16 26 32 46 48 56

     Switch(config)#mls qos map dscp-cos 26 to 3

     Switch(config)#mls qos map dscp-cos 46 to 5

4.   You may be asked to different types of traffic policy maps, or to match certain kinds of traffic.  The first step is to create a class-map to match your traffic, then create a policy-map and then apply that policy-map to an interface.

Easy Cisco ACL Editing

 If you want to make an ACL change at anytime follow these steps of changing an ACL.  

 Login to Router or switch that needs an ACL change. 

 Issue the following command:

Router# sh ip access-lists [access-list name or #]

Note the line numbers of where you need to insert a line or delete a line.

Cisco Nexus Changes

       When you need to insert a line or lines issue the following commands on all Nexus devices:

NexusRouter# conf t

NexusRouter(config)#  ip access-list [name or #]

NexusRouter(config-acl)# (line #) permit (tcp/udp/ip) source ip(x.x.x.x/x) destination ip(y.y.y.y/y) (port)

Cisco IOS Changes

      When you need to insert a line on lines issue the following commands on all Cisco gear except Nexus:

Router# conf t

Router(config)# ip access-list extended [name or #]

Router(config-acl)# (line #) permit (tcp/udp/ip) source ip wildcard mask(x.x.x.x  y.y.y.y) destination ip wildcard mask.

 Lines will never be overwritten during an ACL change it will error out. You will have to say no line number and then renter the line with a new line number.  This is universal against all Cisco gear.

Router(config-acl)#no (line #)

If you need to re-sequence  the line numbers you can by issuing the following commands:

On Nexus Gear:

NexusRouter(config)# resequence ip access-list [name or #] [start #] [increment step]

On  Cisco Gear:

Router(config)# ip access-list resequence [name or #] [start #] [increment step]

My Adventures in the Network

So I thought I would try this again, I was excited the first time I did this and now I think I will start over once again.  I have been studying for my CCIE Wireless exam now for about two years.  I passed the written exam in March of 2012 and have attempted the lab once already and failed.  My next attempt is coming up soon and I thought I would start documenting some of my adventures since. 

I have had a lot of inspirations since I joined twitter of all things.  When I originally started this thing I did not want to start that at all but I have met and learned a ton of knowledge just from all of you.  This world is so connected now and the best part is that we all get to learn from each other so I hope that I can start doing that as well.  So lets get this started.

I passed!

Well good news I passed my ARCH exam and now CCDP certified. Whew I am glad those are done. I guess I will move on to prepare for CCIE. I have learned there are just over a hundred CCNP Wireless in the world I am glad that I am in that group. Cisco just made it over double digits for CCIE Wireless in the world. That would be an accomplishment that I am looking forward to.

On My Way

Well next week I am going to take the Arch Exam so I can get my CCDP. I am debating on what CCIE I want to get after that, I am leaning toward going for my CCIE Wireless because I know there are not many of them and it could set me apart from others, but also I like routing and switching so maybe I should get my CCIE R&S. Maybe I should just do both why not right.

First Post

Welcome to my blog. I am a Network Engineer who specializes in Wi-Fi technology. I wanted to create a place where I can share some of the things I have learned in the industry and to give tips on home wireless as well as my adventures in Networking. I am CCNP, CCNP Wireless, CCDA and Trapeze Wireless Certified. In the future I will post some things I have learned from getting my certificates also my progress in getting my CCIE, either in Routing and Switching, or Wireless maybe both.