[lldp-devel] Question about lldpad and CDP

John Fastabend john.fastabend at gmail.com
Fri Nov 22 18:43:34 UTC 2013


On 11/19/2013 06:27 AM, Sandeep Rao wrote:
> John,
>
> Thank you for the clarification. I was looking to leverage the solution
> for "identifying" the neighbours which happen to be Cisco network gear.
>

LLDP can support this usage model and as far as I know most of the Cisco
network gear support LLDP now.

Look at the "Port Description" and "System Description" TLVs. I don't
have a lot of Cisco gear here but the few switches I do have support
this. You can query this with lldptool via,

# lldptool -t -i ethx -V sysDesc
# lldptool -t -i ethx -V portDesc

Between this and the mandatory TLVs you should be able to identify the
neighbor ports and build a network topology.

You might need to enable and set the TLVs on the switch side to get
your switches to send the TLVs.

> The 4-Wire sounds quite interesting.

Interesting but probably not what you want for network discovery.

>
> I am new to this. I am assuming that I may not be able to leverage
> 4-Wire for indentification. Correct?
>
> Thanks,
> Sandeep
>
>
> ------------------------------------------------------------------------
> *From: * John Fastabend <john.fastabend at gmail.com>;
> *To: * Sandeep Rao <raosande at yahoo.com>;
> *Cc: * lldp-devel at open-lldp.org <lldp-devel at open-lldp.org>;
> *Subject: * Re: [lldp-devel] Question about lldpad and CDP
> *Sent: * Tue, Nov 19, 2013 8:28:02 AM
>
> On 11/18/2013 09:23 AM, Sandeep Rao wrote:
>  > Hi,
>  >
>  > Does lldpad support Cisco Discovery Protocol (CDP)?.
>  >
>  > I tried lldpd and the lldpctl and that does support CDP as it is an
>  > option for the demon startup.
>  >
>  > I would appreciate feedback in this regard.
>  >
>  > Thanks,
>  > Sandeep
>  >
>
> Cisco Discovery Protocol is not currently supported.
>
> However for what its worth the "4-wire Power-via-MDI” LLDP TLV which
> has an equivalent CDP TLV is decoded.
>
>
> Thanks,
>
> John
>
> --
> John Fastabend        Intel Corporation
>


-- 
John Fastabend         Intel Corporation


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