From: Brian Dennis (bdennis@internetworkexpert.com)
Date: Wed Aug 03 2005 - 14:33:48 GMT-3
Dave,
A router learns about it's DLCI's through LMI and not through inverse-ARP. Inverse-ARP has nothing to do with learning DLCI's. I've heard a couple people make the same statement you did before so I'm assuming that there must be some CCIE preparation material that says that. I can tell you that it's an incorrect statement.
Inverse-ARP is disabled for DLCI 102 because there is a static mapping for DLCI 102.
*****************************************
*** InARP Disabled for IP on DLCI 102 ***
*****************************************
interface Serial0/0
no ip address
encapsulation frame-relay
!
interface Serial0/0.1 multipoint
ip address 10.1.1.1 255.255.255.0
frame-relay map ip 10.1.1.1 102 broadcast
Inverse-ARP is disabled because this is a point-to-point subinterface and no mappings are needed.
***********************************
*** InARP Disabled for DLCI 102 ***
***********************************
interface Serial0/0
no ip address
encapsulation frame-relay
!
interface Serial0/0.1 point-to-point
ip address 10.1.1.1 255.255.255.0
frame-relay interface-dlci 102
HTH,
Brian Dennis, CCIE #2210 (R&S/ISP-Dial/Security)
bdennis@internetworkexpert.com
Internetwork Expert, Inc.
http://www.InternetworkExpert.com
Toll Free: 877-224-8987
Direct: 775-745-6404 (Outside the US and Canada)
________________________________________
From: Schulz, Dave [mailto:DSchulz@dpsciences.com]
Sent: Wednesday, August 03, 2005 3:39 AM
To: Brian Dennis; nobody@groupstudy.com; Thomwin Chen ; Desmond Ong ; lab
Subject: RE: frame-relay inverse arp
Brian -
It appears that the last examples have Inarp active, but I must be missing something. There is not a "no frame inverse" command on those two. Also, if you are using subinterfaces and the question wants you to not learn any unused DLCIs, then is it enough to use the "no frame inverse" on only the subinterfaces? Or, should you insure that you have it on the main interface also?
Dave
-----Original Message-----
From: nobody@groupstudy.com
To: Thomwin Chen; Desmond Ong; lab
Sent: 8/3/2005 12:15 AM
Subject: RE: frame-relay inverse arp
Thomwin,
You do not need to disable inverse-ARP on the physical
interfaces if you are using only subinterfaces. This is because the "no
frame-relay inverse-arp" command is not inherited by subinterfaces.
Here are some examples of when inverse-ARP is enabled or disable
based on the configuration itself or based on the use of the "no
frame-relay inverse-arp" command.
**********************************
*** InARP Enabled for DLCI 102 ***
**********************************
interface Serial0/0
no ip address
encapsulation frame-relay
!
interface Serial0/0.1 multipoint
ip address 10.1.1.1 255.255.255.0
frame-relay interface-dlci 102
**********************************
*** InARP Enabled for DLCI 102 ***
**********************************
interface Serial0/0
no ip address
encapsulation frame-relay
no frame-relay inverse-arp
!
interface Serial0/0.1 multipoint
ip address 10.1.1.1 255.255.255.0
frame-relay interface-dlci 102
***********************************
*** InARP Disabled for DLCI 102 ***
***********************************
interface Serial0/0
no ip address
encapsulation frame-relay
!
interface Serial0/0.1 multipoint
ip address 10.1.1.1 255.255.255.0
frame-relay interface-dlci 102
no frame-relay inverse-arp
*****************************************
*** InARP Disabled for IP on DLCI 102 ***
*****************************************
interface Serial0/0
no ip address
encapsulation frame-relay
!
interface Serial0/0.1 multipoint
ip address 10.1.1.1 255.255.255.0
frame-relay interface-dlci 102
no frame-relay inverse-arp IP 102
*****************************************
*** InARP Disabled for IP on DLCI 102 ***
*****************************************
interface Serial0/0
no ip address
encapsulation frame-relay
!
interface Serial0/0.1 multipoint
ip address 10.1.1.1 255.255.255.0
frame-relay map ip 10.1.1.1 102 broadcast
***********************************
*** InARP Disabled for DLCI 102 ***
***********************************
interface Serial0/0
no ip address
encapsulation frame-relay
!
interface Serial0/0.1 point-to-point
ip address 10.1.1.1 255.255.255.0
frame-relay interface-dlci 102
Also it's a myth (aka urban legend ;-) that the "no arp
frame-relay" command stops the replies to inverse-ARP. It doesn't.
HTH,
Brian Dennis, CCIE #2210 (R&S/ISP-Dial/Security)
bdennis@internetworkexpert.com
Internetwork Expert, Inc.
http://www.InternetworkExpert.com
Toll Free: 877-224-8987
Direct: 775-745-6404 (Outside the US and Canada)
-----Original Message-----
From: nobody@groupstudy.com [mailto:nobody@groupstudy.com] On Behalf Of
Thomwin Chen
Sent: Tuesday, August 02, 2005 8:45 PM
To: Desmond Ong; 'lab'
Subject: Re: frame-relay inverse arp
Hi Desmond,
you can test it by using a simple command :
debug frame-relay packet and see why most workbooks suggest no
frame-relay inverse-arp configured on physical FR interface.
probably, you will also need this to know : no arp frame-relay
Rgds,
Thomwin
Desmond Ong <desmond.gk@netstarnetworks.com> wrote:
hi there,
anyone can enlighten me on the following?
when to use "no frame-relay inverse arp" and when to specifically use
"no
frame-relay inverse arp ip " ???
Thanks!
Regards,
Des
This archive was generated by hypermail 2.1.4 : Sun Sep 04 2005 - 17:01:18 GMT-3