CCIE Pilot

Below are my checklist for troubleshooting. The layer 1up approached.

-Administratively down interface?
-IP address correctly applied to an interface? Swapped?
-Check for unwanted secondary ip address?
-Trunk or Access port ethernet interface?
-Vlan association to an interface correct?
-Watch out for tricky IP address name and vlan number?
-Frame-relay lmi type must match -  Cisco, ANSI, Q933a?
-Switchport? or No Switchport?
-Subnet mask consistent?
-Ip routing enabled or not needed?
-Consistent VTP Domain, Password?
-Unwanted dynamic routing protocol running on a router?
-Subnet zero not configured?
-Ip classless configured?
-Ip cef enabled?
-Frame-relay map DLCI mapping correct?

Please feel free to add.

We always see a /32 host route every time we use PPP. What if you dont like and want it? What will you do?

Diagram:

R1-s0/1<<—–Serial-Connection——>s0/1-R2

Answer Configuration: use “no peer neighbor-route” interface command.

R1 and R2

interface Serial0/1
 ip address 12.12.12.x 255.255.255.0
 encapsulation ppp
 no peer neighbor-route

Routing Table: Before

     12.0.0.0/8 is variably subnetted, 2 subnets, 2 masks
C       12.12.12.0/24 is directly connected, Serial0/1
C       12.12.12.2/32 is directly connected, Serial0/1 <<<<< Get rid of this!
After:

Gateway of last resort is not set

     12.0.0.0/24 is subnetted, 1 subnets
C       12.12.12.0 is directly connected, Serial0/1

Verification:

R1#ping 12.12.12.2

Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 12.12.12.2, timeout is 2 seconds:
!!!!!
Success rate is 100 percent (5/5), round-trip min/avg/max = 20/38/56 ms
R1# ping 12.12.12.1

Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 12.12.12.1, timeout is 2 seconds:
!!!!!
Success rate is 100 percent (5/5), round-trip min/avg/max = 52/68/120 ms
R1#

Show to know:

R1#sh int s0/1 | i Open
  Encapsulation PPP, LCP Open
  Open: IPCP, CDPCP, crc 16, loopback not set
R1#

Diagram:

R4-s0/1<<——–Serial-back-2-back———>>s0/1-R5

Question:

Configure PPP on the Serial connection between R4 and R5 using dialer
interfaces.

Answer:

R4 and R5

interface Serial0/1
 no ip address
 encapsulation ppp
 dialer in-band
 dialer pool-member 1
 pulse-time 1

interface Dialer0
 ip address 45.45.45.x 255.255.255.0
 encapsulation ppp
 dialer pool 1
 dialer idle-timeout 0
 dialer persistent
 end

Routing Table:

C       45.45.45.x/32 is directly connected, Dialer0
C       45.45.45.0/24 is directly connected, Dialer0

R4#sh dialer

Se0/1 - dialer type = IN-BAND SYNC NO-PARITY
Dialer pool 1, priority 0
Idle timer (never), Fast idle timer (20 secs)
Wait for carrier (30 secs), Re-enable (15 secs)
Dialer state is data link layer up
Interface bound to profile Di0
Time until disconnect never
Connected to <unknown phone number> (<unknown phone number>)

Di0 - dialer type = DIALER PROFILE
Idle timer (never), Fast idle timer (20 secs)
Wait for carrier (30 secs), Re-enable (15 secs)
Dialer state is data link layer up
Number of active calls = 1
Dial String      Successes   Failures    Last DNIS   Last status

My motivation of this trivia questions is to save myself from the unknown. I’ll do my best to post very quickly those small things that can never be discounted on the real lab.

Question:

• SW1 and SW2 should see each other as CDP neighbors via SW3
across the routed link that connects them.

Diagram:

SW1———-f0/1–SW3–f0/2———SW2

Answer:

SW2:

interface FastEthernet0/1
l2protocol-tunnel cdp
no cdp enable

interface FastEthernet0/2
l2protocol-tunnel cdp
no cdp enable