RE: Encapsulation failed woes

From: Brian Dennis (brian@labforge.com)
Date: Fri Mar 07 2003 - 14:51:23 GMT-3


Jim,
This is a classic example of what someone can run into in the real CCIE
lab and I teach this in my class. You've built a complex ISDN
configuration but a basic ping doesn't even work across it. You
shouldn't build the "whole" solution and then test. You should build it
in "layers" and test it as you add in "features" (ppp callback, ppp
multilink, etc) so you can easily isolate problems. You've got so much
going on with this configuration it's harder to figure out what the
exact problem is and you end up wasting time in the lab trying to find
the problem because of it.

Example:
1) Configure the ISDN spids and switch type then "no shut" the
interface. Then use to "isdn call" command to test and see if a call can
be successfully made across.
2) Next create the dialer interface and bind it to the physical using
the "dialer pool/pool-member" commands. Now add ppp encapsulation to the
physical and dialer interface. Also configure the dialer-string, IP
address, dialer-group and dialer-list (global). After you all have this
on you should be able to ping across.
3) Now add in ppp callback and ping again.
4) Now add in ppp multilink and ping again.
5) Etc.....

Right off the bat looking at your configuration, at least the part you
sent, you have a few different problems. You have "dialer
callback-secure" on the wrong router. You have OSPF authentication on
one side and not the other. You have ppp callback commands under the
physical BRI that aren't needed there. Etc....

Brian Dennis, CCIE #2210 (R&S/ISP Dial/Security)
brian@labforge.com
http://www.labforge.com

-----Original Message-----
From: nobody@groupstudy.com [mailto:nobody@groupstudy.com] On Behalf Of
jim.phillipo@guardent.com
Sent: Friday, March 07, 2003 8:57 AM
To: ccielab@groupstudy.com
Subject: Encapsulation failed woes

I have a couple of routers connected via ISDN with dialer profiles.
Everything connects but I cannot ping the other side and I am getting
the
encapsulation failed message.

I am probably missing something stupid.

Here are the configs:

This is from lab 26 btw.

r5
interface BRI0
 no ip address
 encapsulation ppp
 dialer pool-member 1
 isdn switch-type basic-ni
 isdn spid1 5101 8995101
 isdn spid2 5102 8995102
 ppp callback request
 ppp authentication chap
 ppp multilink
!
interface Dialer0
 ip address 162.17.180.5 255.255.255.0
 encapsulation ppp
 ip ospf message-digest-key 1 md5 cisco
 ip ospf demand-circuit
 dialer pool 1
 dialer callback-secure
 dialer idle-timeout 60
 dialer string 8995202 class r6
 dialer string 8995201 class r6
 dialer load-threshold 1 either
 dialer watch-group 11
 dialer-group 1
 no peer neighbor-route
 pulse-time 0
 ppp callback request
 ppp authentication chap callin
 ppp chap hostname roy
 ppp chap password 7 03005A0703
 ppp multilink

r6
interface BRI0
 no ip address
 encapsulation ppp
 dialer pool-member 1
 isdn switch-type basic-ni
 isdn spid1 5201 8995201
 isdn spid2 5202 8995202
 ppp callback accept
 ppp authentication chap
 ppp multilink
!
interface Dialer0
 ip address 162.17.180.6 255.255.255.0
 encapsulation ppp
 dialer pool 1
 dialer idle-timeout 60
 dialer string 8995101
 dialer string 8995102
 dialer load-threshold 1 either
 dialer max-call 4096
 dialer-group 1
 no peer neighbor-route
 ppp callback accept
 ppp authentication chap
 ppp chap hostname roy
 ppp chap password 7 020205570E
 ppp multilink
!

Jim Phillipo, CCNP, CCDP
Sr. Internetworking Engineer
W: 401.456.1821 F: 401.456.0599 M: 508.982.8923
90 Royal Little Drive, Providence, RI 02904
www.guardent.com



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