https://bugzilla.novell.com/show_bug.cgi?id=795737 https://bugzilla.novell.com/show_bug.cgi?id=795737#c0 Summary: Use of Class A Private Network space as default Classification: openSUSE Product: openSUSE 12.2 Version: Final Platform: All OS/Version: All Status: NEW Severity: Enhancement Priority: P5 - None Component: KVM AssignedTo: kvm-bugs@forge.provo.novell.com ReportedBy: tonysu@su-networking.com QAContact: jdouglas@suse.com Found By: --- Blocker: --- User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:17.0) Gecko/17.0 Firefox/17.0 For awhile KVM networking was working more or less as expected. Then, connected to a large, public shared network (local library system) and all my VM networking died. Upon further investigation, it seems that the Admins for this large, public shared network changed their address space to use the Default Class A Private Network space using the default subnet mask. The characteristics of this particular configuration is that only one network is possible while maximizing the number of possible Hosts. The effect on KVM and any other type of solution that sets up a real or virtual network "behind" the publicly shared network leading to the internet is that because all networks must share the same address space (because it's the Class A Private Network using the default subnet mask) no routing is possible. Reproducible: Always Steps to Reproduce: No Steps to reproduce should be required, the description should be sufficient and self-explanatory. Actual Results: All KVM networking is killed. Although no one should ever setup a Class A Private Network using the default subnet mask, it should be easy to see that not only is it possible and maybe even likely if the Admins are not sufficiently experienced or knowledgeable. In the interests of minimizing possible network address space collisions and improving the chances that an initial setup would work, perhaps another address space could be considered. Using a default subnet mask, there are 15 possible Class B networks (most using 16, the lowest second octet) while still supporting a multitude of possible addresses. There are even more possible Class C networks (using the default subnet mask) but of course with only 253 possible Host addresses, but is that sufficient? Am recommending only an "Enhancement" priority only because I assume that this problem has not been encountered often yet should be weighed against the serious ramifications when this scenario is encountered. -- Configure bugmail: https://bugzilla.novell.com/userprefs.cgi?tab=email ------- You are receiving this mail because: ------- You are on the CC list for the bug.