[j-nsp] Mirroring IPv6 neighbor advertisements

[Jason Healy]

On Apr 16, 2019, at 12:46 PM, James Stapley <j.stapley at ru.ac.za> wrote:
> 
> This is the most relevant SNMP OID I've found:
> https://apps.juniper.net/mib-explorer/navigate.jsp#object=ipNetToPhysicalTable&product=Junos%20OS&release=17.3R3
> 
> That all needs to be regularly slurped into a database of some kind, and
> then you need some tools for your support agents / sysadmins to query it...
> 
> I've not yet gone much beyond thinking up the above, but it's going to need
> to be built at some stage!

James,

Thanks for your email.  After messing around a big longer, we finally settled on polling, as you mentioned above.

We started out with SNMP, but walking the tables took a fair amount of clock/cpu time.  We ran some tests and found that netconf over SSH had less overhead in our setup, even when accounting for the SSH setup and teardown.  We now have a script that happily sucks up the ND table once or twice a minute and parses all the entries.  The netconf output had some additional items (like ageout) that help us track adds, refreshes, and deletes (much like DHCP discover, renew, and release), which works better for our linear logging.  Again, you could probably do just as much with SNMP, but this was easier to script and had better performance.

We haven't started on the "database" part just yet, but there are some things out there that have tried to do this:

http://netdisco.org

No idea if it handles IPv6 yet (been a few years since we've tried it), but on v4 it did most of the "accounting" type stuff you mentioned.

Thanks,

Jason