[j-nsp] SNMP on logical-system fxp0

[Chip Marshall]

So, I have an MX5 with it's fxp0 management interface connect to
one network, which I've placed in a logical-system so it can have
it's own default route for out-of-band management.

> show configuration logical-systems
Management {
    interfaces {
        fxp0 {
            unit 0 {
                family inet {
                    address 172.16.10.4/24;
                }
            }
        }
    }
    routing-options {
        static {
            route 0.0.0.0/0 next-hop 172.16.10.1;
        }
    }
}

I've also enabled SNMP:

community public {
    authorization read-only;
    clients {
        172.16.10.0/24;
    }
}
traceoptions {
    file size 10m files 10;
    flag all;
}

And I've confirmed that SNMP requests are being received and
answered based on the snmpd trace logs.

The problem is the replies to SNMP queries are being routed out
using the main system's routing table, not the routing table of
the logical-system. I have confirmed this with packet captures.

I'm at a bit of a loss on how to correct for this. If it were a
routing-instance, I could just export the direct route into the
main inet.0, but that doesn't appear to be possible with a logical-
system, and I can't use fxp0 with a routing-instance.

I feel like this should be a fairly common configuration, placing
the management interface out-of-band and doing SNMP on that
interface, but I haven't found a lot of useful information
through searching.

Any recommendations?

-- 
Chip Marshall <chip at 2bithacker.net>
http://2bithacker.net/