[openstack-dev] [Neutron] L3 HA VRRP concerns

Assaf Muller amuller at redhat.com
Mon Feb 24 15:58:16 UTC 2014


Hi everyone,

A few concerns have popped up recently about [1] which I'd like to share and discuss,
and would love to hear your thoughts Sylvain.

1) Is there a way through the API to know, for a given router, what agent is hosting
the active instance? This might be very important for admins to know.

2) The current approach is to create an administrative network and subnet for VRRP traffic per router group /
per router. Is this network counted in the quota for the tenant? (Clearly it shouldn't). Same
question for the HA ports created for each router instance.

3) The administrative network is created per router and takes away from the VLAN ranges if using
VLAN tenant networks (For a tunneling based deployment this is a non-issue). Maybe we could
consider a change that creates an administrative network per tenant (Which would then limit
the solution to up to 255 routers because of VRRP'd group limit), or an admin network per 255
routers?

4) Maybe the VRRP hello and dead times should be configurable? I can see admins that would love to
up or down these numbers.

5) The administrative / VRRP networks, subnets and ports that are created - Will they be marked in any way
as an 'internal' network or some equivalent tag? Otherwise they'd show up when running neutron net-list,
in the Horizon networks listing as well as the graphical topology drawing (Which, personally, is what
bothers me most about this). I'd love them tagged and hidden from the normal net-list output,
and something like a 'neutron net-list --all' introduced.

6) The IP subnet chosen for VRRP traffic is specified in neutron.conf. If a tenant creates a subnet
with the same range, and attaches a HA router to that subnet, the operation will fail as the router
cannot have different interfaces belonging to the same subnet. Nir suggested to look into using
the 169.254.0.0/16 range as the default because we know it will (hopefully) not be allocated by tenants.

[1] https://blueprints.launchpad.net/neutron/+spec/l3-high-availability


Assaf Muller, Cloud Networking Engineer 
Red Hat 



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