Open Stack

So, I've got an Icehouse cloud that had been working fine; then we had 
to bring everything down for an extended power outage, and stuff still 
isn't quite right.  The nutshell problem is that only one of my two 
neutron gateways seems to be able to route to the metadata server.  The 
"working" neutron gateway, however, has switched after a reboot.

Symptoms:
* Initially, I set eth0 to point to my first neutron gateway 
(hereinafter "NG")
* It failed to be able to access the metadata server (verified by 
telnetting to 169.254.169.254:80)
* Associating eth0 with the secondary NG worked fine
* All this held true through multiple VM reboots, and a cloud controller 
reboot

I then rebooted, respectively, the primary NG, the secondary NG, and the 
cloud controller

When everything came back up, the "functioning" NG had swapped to the 
primary.  Note that, otherwise, the gateways both work great -- DHCP 
addresses are assigned; I can ping internally; I can ping externally; I 
can access floating IPs.  Just the metadata server access doesn't work.

Last datapoint: I've noticed that when I have multiple NICs, one per NG, 
a static host route to 169.254.169.254 can sometimes be assigned by 
DHCP; that is not assigned by the non-functional NG.  (I can't decide if 
that's expected behavior or not, but figured someone more conversant 
than I might know.)

Any ideas on what I should be digging into?  I've gone down lots of 
rabbit holes, but am uncertain where to dig further.

Thanks,

-Ken