Re: IP unnumbered question

check the difference in the routing tables between the PPP and HDLC and see
what the destination interface is, when the route recursion happens to
forward the packet...

HDLC forwards to Loopback0, check the debug ip packet detail:
R10#sh ip route
     1.0.0.0/24 is subnetted, 1 subnets
C 1.1.1.0 is directly connected, Loopback0
R10#ping 1.1.1.1 r 1

Type escape sequence to abort.
Sending 1, 100-byte ICMP Echos to 1.1.1.1, timeout is 2 seconds:

IP: tableid=0, s=1.1.1.2 (local), d=1.1.1.1 (Loopback0), routed via RIB
IP: s=1.1.1.2 (local), d=1.1.1.1 (Loopback0), len 100, sending
    ICMP type=8, code=0
IP: tableid=0, s=1.1.1.2 (Loopback0), d=1.1.1.1 (Loopback0), routed via RIB
IP: s=1.1.1.2 (Loopback0), d=1.1.1.1 (Loopback0), len 100, rcvd local pkt
    ICMP type=8, code=0.
Success rate is 0 percent (0/1)

PPP check the routing table and debup ip packet detail packet going out
Serial0/0:
R10#sh ip route
     1.0.0.0/8 is variably subnetted, 2 subnets, 2 masks
C 1.1.1.1/32 is directly connected, Serial0/0
C 1.1.1.0/24 is directly connected, Loopback0

R10#ping 1.1.1.1 r 1

Type escape sequence to abort.
Sending 1, 100-byte ICMP Echos to 1.1.1.1, timeout is 2 seconds:
!
Success rate is 100 percent (1/1), round-trip min/avg/max = 92/92/92 ms
R10#
IP: tableid=0, s=1.1.1.2 (local), d=1.1.1.1 (Serial0/0), routed via FIB
IP: s=1.1.1.2 (local), d=1.1.1.1 (Serial0/0), len 100, sending
    ICMP type=8, code=0
IP: tableid=0, s=1.1.1.1 (Serial0/0), d=1.1.1.2 (Loopback0), routed via RIB
IP: s=1.1.1.1 (Serial0/0), d=1.1.1.2, len 100, rcvd 4
    ICMP type=0, code=0

Check the PPP debug and watch it add the host route, look for remove and
install route below:

R10#debug ppp negotiation
PPP protocol negotiation debugging is on
R10#conf t
Enter configuration commands, one per line. End with CNTL/Z.
R10(config)#int s0/0
R10(config-if)#shut
R10(config-if)#
%LINK-5-CHANGED: Interface Serial0/0, changed state to administratively down
Se0/0 PPP: Sending Acct Event[Down] id[3]
Se0/0 CDPCP: State is Closed
Se0/0 IPCP: State is Closed
Se0/0 PPP: Phase is TERMINATING
Se0/0 LCP: State is Closed
Se0/0 PPP: Phase is DOWN
Se0/0 IPCP: Remove route to 1.1.1.1
%LINEPROTO-5-UPDOWN: Line protocol on Interface Serial0/0, changed state to
down
R10(config-if)#no shut
R10(config-if)#
Se0/0 PPP: Outbound cdp packet dropped
%LINK-3-UPDOWN: Interface Serial0/0, changed state to up
Se0/0 PPP: Using default call direction
Se0/0 PPP: Treating connection as a dedicated line
Se0/0 PPP: Session handle[F0000002] Session id[2]
Se0/0 PPP: Phase is ESTABLISHING, Active Open
Se0/0 LCP: O CONFREQ [Closed] id 2 len 10
Se0/0 LCP: MagicNumber 0x151A2C5E (0x0506151A2C5E)
Se0/0 LCP: I CONFREQ [REQsent] id 8 len 10
Se0/0 LCP: MagicNumber 0x161C632E (0x0506161C632E)
Se0/0 LCP: O CONFACK [REQsent] id 8 len 10
Se0/0 LCP: MagicNumber 0x161C632E (0x0506161C632E)
Se0/0 LCP: I CONFACK [ACKsent] id 2 len 10
Se0/0 LCP: MagicNumber 0x151A2C5E (0x0506151A2C5E)
Se0/0 LCP: State is Open
Se0/0 PPP: Phase is FORWARDING, Attempting Forward
Se0/0 PPP: Phase is ESTABLISHING, Finish LCP
Se0/0 PPP: Phase is UP
Se0/0 IPCP: O CONFREQ [Closed] id 1 len 10
Se0/0 IPCP: Address 1.1.1.2 (0x030601010102)
Se0/0 CDPCP: O CONFREQ [Closed] id 1 len 4
Se0/0 PPP: Process pending ncp packets
Se0/0 IPCP: I CONFREQ [REQsent] id 1 len 10
Se0/0 IPCP: Address 1.1.1.1 (0x030601010101)
Se0/0 IPCP: O CONFACK [REQsent] id 1 len 10
Se0/0 IPCP: Address 1.1.1.1 (0x030601010101)
Se0/0 IPCP: I CONFACK [ACKsent] id 1 len 10
Se0/0 IPCP: Address 1.1.1.2 (0x030601010102)
Se0/0 IPCP: State is Open
Se0/0 CDPCP: I CONFREQ [REQsent] id 1 len 4
Se0/0 CDPCP: O CONFACK [REQsent] id 1 len 4
Se0/0 CDPCP: I CONFACK [ACKsent] id 1 len 4
Se0/0 CDPCP: State is Open
Se0/0 IPCP: Install route to 1.1.1.1
%LINEPROTO-5-UPDOWN: Line protocol on Interface Serial0/0, changed state to
up

On Wed, Jan 27, 2010 at 9:01 PM, Naufal Jamal <naufalccie_at_yahoo.in> wrote:

> I got a small question over ip unnumberd.
> I have two simple routers connected thru s0/0 interfaces
> on one router i have configured the interfaces as below
> 1)Does ipunnumbered has got to do with the encapsulation of the poin to
> point
> link.why is it not working with the default enc HDLC? when I give enc ppp
> on
> both the interfaces the ping works fine between the routers else it
> doesnt...
> Pls clarify...
>
> R0#sh run int s0/0
>
> Building configuration...
> Current configuration : 76 bytes
> !
> interface Serial0/0
> ip unnumbered Loopback0
> serial restart_delay 0
> end
> R0#sh run int lo0
> Building configuration...
> Current configuration : 61 bytes
> !
> interface Loopback0
> ip address 1.1.1.4 255.255.255.0
> end
> ======
> R1#sh run int s0/0
> Building configuration...
> Current configuration : 85 bytes
> !
> interface Serial0/0
> ip address 1.1.1.2 255.255.255.0
> serial restart_delay 0
> end
> ======
>
>
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-- 
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