network cisco ccna gns3 certification arteq

network cisco ccna gns3 certification arteq
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Sunday, February 3, 2013

bgp states...

the ccie is your super bowl... the ccie doesn't happen after the super bowl, or during the halftime show... the ccie doesn't get postponed by reruns of breaking bad or the latest zombie stupidity out there... the ccie is always there, taunting you, telling you you're not good enough... get pissed...

do you have these memorized? are they second nature? if this ever gets old  you will never be ccie...  does scott morris sleep? of course not... wake up...

do you know all of ospf's lsa's... the opaque's too...

router, network, network summary, summary asbr, external, nssa... that's 1,2,3,4,5 and 7... 6 is group or mospf, 8 is external, 9,10,11 are opaque, link-local scope, area local scope, AS scope

what are the eigrp packet types, there are 7?
hello, update, query, reply, ack, sia query, sia reply...
which ones require an ack? hint, it's not hello or ack...

ospf neighbor states:
down, attempt (nbma), init, two way, exstart, exchange, loading, full

ip packet header:
v,hl,diffserv,total length,identification,flags,frag offset,ttl,protocol, header checksum, sa,da,options,data

ospf network types:
broadcast, nbma, point-to-point, multipoint b'cast, and mpoint nbma

bgp attribute preference:
w,lp,local origination,as-path,origin code, lowest med, ebgp/ibgp, ibgp to bgp next hop, age, rid

ospf router types:
bb, internal, abr,asbr

ospf packets:
hello, dbd, lsr, lsu, lsa

ospf areas:
bb,standard, stub, totally stub, nssa, virtual link

what are you waiting for? get back to your lab...

here is a nice little write up from this guy...

1. IDLE State :  veryfing route to neighbor
BGP refuses all incoming connections. No BGP resources are allocated in Idle state, and no incoming BGP connections are allowed.

2. Connect State : 
BGP waits for a TCP connection to be completed. If successful, the BGP state machine moves into OpenSent state after sending the OPEN message to the peer. Failure in this state could result in either going into Active state or Connect state, or reverting back to Idle state, depending on the failure reasons.

3. Active State : attempting connectivity to neighbor
In this state, a TCP connection is initiated to establish a BGP peer relationship. If successful, BGP sends its OPEN message to the peer and moves to OpenSent state. Failure can result in going to the Active or Idle states.

4. OpentSent State : open message sent to neighbor
After sending an OPEN message to the peer, BGP waits in this state for the OPEN reply.
If a successful reply comes in, the BGP state moves to OpenConfirm and a keepalive is sent to the peer. Failure can result in sending the BGP state back to Idle or Active.

5. OpenConfirm State : neighbor replied with open message
The BGP state machine is one step away from reaching its final state (Established).
BGP waits in this state for keepalives from the peer. If successful, the state moves to Established; otherwise, the state moves back to Idle based on the errors.

6. Established State : connection between neighbors established
This is the state in which BGP can exchange information between the peers. The information can be updates, keepalives, or notification.

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