[j-nsp] SNMP walk on JunOS from inside a routing instance

[James Bensley]

Hi All,

I am migrating from one Cacti box to another, the new one polls some
MX boxes inside a routing instance but the old one polls in inet0 in
no routing instance.

When I snmpwalk the MX boxes from the new Cacti box I am only returned
the interfaces which are inside that routing instance the poll comes
in on. On the old Cacti box SNMP returns all interfaces, including
those inside all routing instances.

Does Junos restrict the SNMP output to that which relates to the
routing instance only, when polling in a routing instance?

username at mxrouter> show configuration snmp
community SecretCommunity {
    authorization read-only;
    routing-instance SNMP-TEST {
        clients {
            10.0.0.0/8;
        }
    }
}

username at mxrouter> show interfaces terse routing-instance TEST-SNMP
Interface               Admin Link Proto    Local                 Remote
vt-0/0/10.1054          up    up   inet
ge-0/3/7.2012           up    up   inet     172.21.18.53/30
                                   multiservice
ge-2/3/7.2013           up    up   inet     172.21.18.57/30
                                   multiservice
ae0.2047                up    up   inet     10.254.240.1/24
                                   multiservice
lo0.2047                up    up   inet     10.254.242.1        --> 0/0


[root at cacti ~]#  snmpwalk -v 2c -c TEST-SNMP at SecretCommunity
10.254.242.1 .iso | grep ifDesc
IF-MIB::ifDescr.6 = STRING: lo0
IF-MIB::ifDescr.556 = STRING: ge-0/3/7
IF-MIB::ifDescr.571 = STRING: vt-0/0/10
IF-MIB::ifDescr.581 = STRING: ae0
IF-MIB::ifDescr.1220 = STRING: lo0.2047
IF-MIB::ifDescr.1242 = STRING: ae0.2047
IF-MIB::ifDescr.1342 = STRING: ge-0/3/7.2012
IF-MIB::ifDescr.1343 = STRING: ge-2/3/7.2013
IF-MIB::ifDescr.2936 = STRING: ge-2/3/7
IF-MIB::ifDescr.43020 = STRING: vt-0/0/10.1054

This example system is on 11.4R6.5, but we have a range of Junos
versions across MX480s & MX960s and it's the same behaviour for all of
them.

Any info and help with getting all interfaces returned when polling
from within a routing instance would be appreciated.

Cheers,
James.