From: Elias Aggelidis (eaggel@xxxxxxxxxxx)
Date: Mon Apr 16 2001 - 10:23:07 GMT-3
Dear All,
John has absolute right !
CCO says :
>>"The Cisco Discovery Protocol (CDP) is media- and protocol-independent,
and runs on all Cisco-manufactured equipment including routers, bridges,
access servers,
and switches. With CDP, network management applications can learn the device
type and the SNMP agent address of neighboring devices. This enables
applications to send SNMP queries to neighboring devices.
CDP runs on all media that support Subnetwork Access Protocol (SNAP),
including local-area network (LAN), Frame Relay, and Asynchronous Transfer
Mode
(ATM) media. CDP runs over the data link layer only. Therefore, two systems
that support different network-layer protocols can learn about each other.
Each device configured for CDP sends periodic messages to a multicast
address. Each device advertises at least one address at which it can receive
SNMP
messages. The advertisements also contain time-to-live, or holdtime,
information, which indicates the length of time a receiving device should
hold CDP information
before discarding it.
There is a CDP MIB for the management of CDP on Cisco devices."
So If you enable cdp on a multipoint X25,Frame-Relay/ATM interface
you will see you neighbours.
I tried and it works! (I have forgotten that cdp is disable by default on a
frame-relay multipoint interface)
Thanks John.
****************************************************************
Elias Aggelidis ALGOSYSTEMS SA
Senior Network Engineer 4, Sardeon Str
CCNA, CCNP Nea Smyrni
CVOICE, Security Specialised
PICA Administrator
Athens 17121
tel: +301-9310281 GREECE
fax: +301-9352873
email: eaggel@algo.com.gr
****************************************************************
-----Original Message-----
From: John Mistichelli [mailto:jmistich@earthlink.net]
Sent: ?e?t??a, 16 ?p?????? 2001 4:12 55
To: Elias Aggelidis; Corey M. Ellis; CCIE Mailist
Subject: Re: CDP on Multipoint FR interfaces!!
CDP uses a multicast address for its periodic advertisements. To make it
work on frame relay you will have to enable support for broadcast on the VC
and simply use the command "cdp enable" on your frame relay interface. On a
frame relay interface it is not on by default. Broadcast is enabled by
default if you use IARP to learn remote IP addresses. You will have to use
the "BROADCAST" keyword if you are using frame-relay map statements.
Hope that helps
John
----- Original Message -----
From: "Elias Aggelidis" <eaggel@algo.com.gr>
To: "Corey M. Ellis" <coreye@odigo.com>; "CCIE Mailist"
<ccielab@groupstudy.com>
Sent: Monday, April 16, 2001 8:26 AM
Subject: RE: CDP on Multipoint FR interfaces!!
> Dear All,
>
> CDP is a broadcast Layer 2 protocol so in order to work on
> a multipoint non broadcast network you have to make some
> maps in you hup and spoke topology.
>
> I have not try but I think that if map bridging on the frame-relay
interface
> and of course enable bridging on this interfaces cdp will work.
>
> In a point to point topology you would not have any problems.
>
> Regards
>
> Elias Aggelidis
>
>
> ****************************************************************
> Elias Aggelidis ALGOSYSTEMS SA
> Senior Network Engineer 4, Sardeon Str
> CCNA, CCNP Nea Smyrni
> CVOICE, Security Specialised
> PICA Administrator
> Athens 17121
> tel: +301-9310281 GREECE
> fax: +301-9352873
> email: eaggel@algo.com.gr
> ****************************************************************
>
>
> -----Original Message-----
> From: nobody@groupstudy.com [mailto:nobody@groupstudy.com]On Behalf Of
Corey
> M. Ellis
> Sent: S?__at?, 14 ?p?????? 2001 7:01 55
> To: CCIE Mailist
> Subject: CDP on Multipoint FR interfaces!!
>
>
> Hi all,
>
> when I do a show cdp neigh on my frame connected routers "spokes are
> physical, and hub is multipoint" I don't get anything. CDP is on by
default,
> and I even manually enabled it, still nothing. One spoke as a router
> connected to it via another serial connection and that is fine. I must be
> missing something about CDP not working on multipoint frame connections.
On
> the CD it says that CDP works on LAN, Frame, ATM interfaces. Please
advise.
>
> thanks
>
> Corey M. Ellis
> **Please read:http://www.groupstudy.com/list/posting.html
**Please read:http://www.groupstudy.com/list/posting.html
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