CCIE Candidate.com: Keith Tokash Is The New Dread Pirate Roberts

Ethan Banks recently ascended into the ranks of the numbered, but his blog still lives on.  Keith “Genghis” Tokash has begun posting his quest for the CCIE.  He’s from LA and works for MySpace.  He seems to be a good guy although he did once dis Fremont (I’ll try not to hold a grudge :-)  ).  You can check out his posts here.

He has attended both the Micronics (Nabrik) and Unitek CCIE bootcamps.  He has posted a very good review of the Unitek bootcamp (as well as some comparisons to Narbik’s camp) here.

Good luck to Keith (it sounds like he’s close to the end of his journey) and be sure to check out his posts.

Question Of The Day: 20 May, 2008

Topic: OSPF

You’ve rolled out your new OSPF auto-cost command to your network.  It looks like one of your colleagues has adjusted the OSPF cost of interface FastEthernet0/0.  That interface should have an OSPF cost of 1000.  What will it’s OSPF cost be based on the following configuration:

interface FastEthernet0/0
 description ->r2 fa0/0
 ip address 100.1.12.1 255.255.255.0
 ip ospf cost 10
 !
router ospf 100
 router-id 1.1.1.1
 auto-cost reference-bandwidth 100000
 network 100.1.12.1 0.0.0.0 area 0
 network 100.1.12.1 0.0.0.0 area 0

Click Here For The Answer

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Yesterday’s Question

Question Of The Day: 19 May, 2008 

You’ve rolled out your new OSPF auto-cost command to your network.  It looks like you’ve missed a router.  r1 is peered with r2 over an Ethernet connection.  r1 has been updated with the new reference bandwidth, but r2 has not.

r1
router ospf 100
 auto-cost reference-bandwidth 100000
 network 10.1.12.1 0.0.0.0 area 0
!
interface FastEthenet 0/0
 ip address 10.1.12.1 255.255.255.0

r2
router ospf 100
 network 10.1.12.2 0.0.0.0 area 0
!
interface FastEthenet 0/0
 ip address 10.1.12.2 255.255.255.0

Will these routers form an OSPF neighbor adjacency?

Answer: Yes, the routers will form an OSPF adjacency.

r1 is peered with r2:

r1(config)#do show ip ospf neighbor

Neighbor ID     Pri   State           Dead Time   Address         Interface
2.2.2.2           0   FULL/  -        00:00:37    10.1.12.2       FastEthernet0/0

r1(config-router)#do show ip ospf neighbor detail | i interface|State|is up
 Neighbor 2.2.2.2, interface address 10.1.12.2
    In the area 0 via interface FastEthernet0/0
    Neighbor priority is 0, State is FULL, 6 state changes
    Neighbor is up for 00:11:42

Now let’s change the bandwidth-reference on r1:

r1(config)#router ospf 100
r1(config-router)#auto-cost reference-bandwidth 100000
% OSPF: Reference bandwidth is changed.
        Please ensure reference bandwidth is consistent across all routers.

The peering does not drop:

r1(config)#do show ip ospf neighbor

Neighbor ID     Pri   State           Dead Time   Address         Interface
2.2.2.2           0   FULL/  -        00:00:35    10.1.12.2       FastEthernet0/0

r1(config)#do show ip ospf neighbor detail | i interface|State|is up
 Neighbor 2.2.2.2, interface address 10.1.12.2
    In the area 0 via interface FastEthernet0/0
    Neighbor priority is 0, State is FULL, 6 state changes
    Neighbor is up for 00:14:38

I guess that this should not come as a surprise as reference-bandwidth is not one of the required attributes to establish an OSPF neighbor adjacency.

r1#show ip ospf interface brief
Interface    PID   Area            IP Address/Mask    Cost  State Nbrs F/C
Se1/0        100   0               10.1.12.1/24       1000 P2P   1/1

r2#show ip ospf interface brief
Interface    PID   Area            IP Address/Mask    Cost  State Nbrs F/C
Fa0/0        100   0               10.1.12.2/24       1    P2P   1/1