On Sat, Jan 09, 2016 at 08:29:39PM +0100, Guus Sliepen wrote: > > If /etc/network/interfaces defines 2 protocols for one interface, > > then a tiny problem for one protocol can affect both. > > This is by design. Recent versions of ifupdown will even exit with an > error code if there is an error while configuring any part of an > interface.
The Debian cloud team is encountering this same issue and it's making it difficult to produce cloud images that support IPv6. AWS recently announced IPv6 support within their cloud environment, which is one of the ones supported by the cloud team. IPv6 support is an optional feature that an AWS user can configure on a per host or per virtual network (VPC) basis. We would like to produce a single cloud image that can work in either configuration. The obvious approach to this would be to use the following in /etc/network/interfaces: iface eth0 inet dhcp iface eth0 inet6 dhcp This works well in the case where an instance launches in a network that does support IPv6, but prevents the system from successfully booting in an IPv4-only network. (IPv6-only is not currently supported by AWS and thus not currently an issue for us, but in theory it would have the same problem.) If you're not willing to change the default behavior of ifupdown, I'd like to request one of the following: 1. Provide a new keyword, maybe "optional" that can be associated with one of the interface variants that indicates to ifupdown that a failure to configure the variant in question should not be fatal. or 2. Help us to come up with some other solution within the bounds of the current ifupdown behavior to accomplish what we're trying to do. Thanks noah
signature.asc
Description: PGP signature
