Restriction on numbering VLANs

[wat]

I'm using vlan tags 100 through 200, and set subnet configurations in eucalyptus.conf as

VNET_SUBNET="192.168.234.0"
VNET_NETMASK="255.255.255.0"
VNET_ADDRSPERNET="16"

Launching an instance on this setting fails with an "out of range" error.
--- cc.log -------------------------------------------------------------
[Mon Mar 7 18:44:17 2011][007559][EUCAERROR ] vnetAddHost(): failed to add host d0:0d:46:E5:08:B0 on vlan 10
[Wed Mar 9 18:24:03 2011][001791][EUCAERROR ] vnetStartNetworkManaged(): supplied vlan '100' is out of range (0 - 15), cannot start network
------------------------------------------------------------------------
It seems like the error occurs with the small number of security groups like:
[range of VNET_SUBNET] / VNET_ADDRSPERNET <= 16

This restricts the network environments where eucalyptus can run on.

system:
Eucalyptus : 2.0.2
Host : CentOS5.5
Installed : binary(eucalyptus-2.0.2-centos-x86_64.tar.gz)
Hypervisor : kvm

[Daniel Nurmi (nurmi)]

The VNET_SUBNET/VNET_NETMASK defined pool of IPs must be large enough for the required VLAN range to be indexed into the range. With the current settings (range makes 254 IPs available), with subnets of size 16, only VLANs 2-15 would work. In order to allow the system to use VLANs 100-200, with subnets of size 16, we need a range of IPs that is at least ~4096 in size:

192.168.0.0
255.255.240.0

for example, would cover it.

[Daniel Nurmi (nurmi)]

In the future, we would like to decouple the actual VLAN tag from the size of the subnet (meaning that if a user wanted to use 100 VLAN networks (independent of which tags they are), your specified pool of IPs would only need to be large enough to handle NUMBER_OF_VLANS*SIZEOFNETWORK. Marking this bug as 'wishlist' until that feature arrives!

[Andy Grimm (agrimm)]

This issue is now being tracked upstream at http://eucalyptus.atlassian.net/browse/EUCA-2761

Please watch that issue for further updates.