Once you're finding out to cross the Cisco CCNA and CCNP certification exams, you rapidly learn that there's at all times one thing else to learn. (You'll really decide up on this in your CCIE studies, trust me!) At the moment we'll check out an usually-neglected topic in Frame Relay, the encapsulation type. You do not precisely change this every day in manufacturing networks (not if you want to keep employed, anyway!), but it's an essential examination subject that you simply must be familiar with.
The DCE and DTE must agree on the LMI type, but there's another worth that must be agreed upon by the 2 DTEs serving because the endpoints of the VC. The Body encapsulation can be left at the default of Cisco (which is Cisco-proprietary), or it can be changed to the business-customary IETF, as proven below. If a non-Cisco router is the remote endpoint, IETF encapsulation must be used. Note that the default of Cisco is not listed as an option by IOS Help, so you higher know that one by heart!
R1(config)int s0
R1(config-if)encap frame ?
ietf Use RFC1490/RFC2427 encapsulation
R1(config-if)encap frame ietf
What if a bodily interface is in use and some distant hosts require Cisco encapsulation and others require IETF? The encapsulation kind could be configured on a per-PVC foundation as well. One encap type can be utilized on the interface, and any map statements that require a different encap sort can have that specified in the appropriate map statement. In the following instance, all PVCs will use the default Cisco encapsulation sort aside from PVC 115. The frame map assertion utilizing that PVC has ietf specified.
R1(config)int s0/zero
R1(config-if)encap body
R1(config-if)frame map ip 172.12.123.3 123 broadcast
R1(config-if)body map ip 172.12.123.2 122 ietf broadcast
present body map shows us that the mapping to DLCI 123 is using Cisco encapsulation, and DLCI 122 is utilizing IETF.
R1show body map
Serial0 (up): ip 172.12.123.3 dlci 123(0x7B,0x1CB0), static
broadcast, CISCO, standing outlined, energetic
Serial0 (up): ip 172.12.123.2 dlci 122(0x7B,0x1CB0), static
broadcast, ietf, standing defined, lively
Simply keep in mind that Cisco is the default, and all PVCs will use Cisco until you specify IETF in the frame map statement itself. You could possibly also change the whole interface to use IETF for all mappings with the body-relay encapsulation IETF command. For Cisco exams, in addition to work on production networks, it is always a good idea to know a couple of approach to do something!
As a CCNA or CCNP, one factor you've got to get used to is that change is constant. Cisco repeatedly points new IOS variations, not to point out the many different sorts of hardware they produce! While it is at all times good to have "the most recent and the greatest" relating to routers, switches, firewalls, etc., we now have to be prepared for the fact that not all our shoppers are going to have that latest and best!
For example, there are nonetheless fairly a number of Catalyst 5000 switches on the market humming away, and in the event you're used to engaged on IOS-pushed switches just like the 2950, the same command can have dramatically different results.
As an instance you are going to look at the spanning tree protocol (STP) setup of a brand new client. You are used to working with newer 2950 switches, and you've at all times run present span on those switches to display spanning-tree information. Then, you run show span on a Catalyst 5000 - and one thing like this shows:
change (enable) present span
Destination : Port 6/1
Admin Source : Port 6/2
Oper Supply : Port 6/2
Course : transmit/receive
Incoming Packets: disabled
Learning : enabled
Multicast : enabled
Filter : -
Standing : lively
Whole native span periods: 1
What's going on right here?
The command present span on a 5000 won't present spanning tree stats - as a substitute, what you are going to see are statistics referring to Switched Port ANalyzer (SPAN). Surprise!
Think about an instance the place you're used to working show span on 5000 switches to see SPAN information. Once you run that on a 2950, you know now what you are going to get - spanning tree data! On a 2950, you will have to run show monitor session, adopted by the SPAN session number.
SW1show monitor session 1
Session 1
---------
Sort : Local Session
Supply Ports :
Each : Fa0/1
Destination Ports : Fa0/2
Encapsulation : Native
Ingress: Disabled
As a CCNA and CCNP, this is one of those belongings you simply must get used to. Commands are going to be different, typically radically so, between models. That's why you want to be adept with both IOS Assist and Cisco's on-line documentation site. IOS Help is straightforward, but the on-line doc web site take just a little getting used to. When you learn to navigate that website, a world of Cisco information is at your fingertips.
In addition to, when you sit for the CCIE lab examination, that will be the solely pal you have got! And a worthwhile friend it may be - you're simply going to must belief
