Morten, 

    y.x.204.217 is an SNMP-enabled device, but I don't know if it has switch forwarding tables... It is a printer (Lexmark X464de). But this is a strange behaviour because there are other printers like that (with the same model) that are shown in netmap. I've already revised the snmp configuration and everything is good.

    Today, that device was maped into netmap. I think some strange behaviour was occured with that device which caused the error.

    If this error occurs again, how can I debug it? Is there any snmp command that I can exec to see with tcpdump what is happening?




2013/7/29 Morten Brekkevold <morten.brekkevold@uninett.no>
On Thu, 18 Jul 2013 17:53:47 -0300 Bruno Galindro da Costa <bruno.galindro@gmail.com> wrote:

>     To temporaly "solve" this issue, I've enabled LLDP on all switches.
>
>     But, this issue accours with other netboxes that doesn't have lldp
> protocol (like printers and some wireless devices). I've found on navtopology's
> debug log these errors that maybe point us to a solution:
>
> DEBUG:nav.topology.vlan:could not find reverse edge for (<Netbox:
> y.x.250.134>, <Netbox: y.x.204.217>, <Interface: 5:18 at y.x.250.134>)
>
>     What meaning these messages?

This message means that the topology detector has found out from
y.x.250.134 that it's interface 5:18 is connected to y.x.204.217. It
has, however, not found any information from y.x.204.217 that it is
connected back to y.x.250.134.

This is typically the case with servers and other devices that don't
talk SNMP. It is not a problem, unless y.x.204.217 is an SNMP-enabled
device that has switch forwarding tables or LLDP/CDP support.

--
Morten Brekkevold
UNINETT



--
Att.
Bruno Galindro da Costa