[atlas] Strange IPv6 problem with Atlas
Philip Homburg philip.homburg at ripe.net
Tue Oct 2 09:34:15 CEST 2012
On 10/2/12 3:14 , Lorenzo Colitti wrote: > > > That said - why is SSH trying to communicate over IPv6 with a > link-local address in the first place? getaddrinfo should be ranking > the global IPv4 address above the link-local IPv6 address and thus > causing SSH to prefer IPv4... I have to check, but my guess is that no sorting is being done at all. The probe software is built on top of ucLinux. Large parts of ucLinux are reimplementations with a focus on compactness. I wondered why we never noticed this before. The reason is two fold. One is that dbclient is just about the only part in the Atlas software that can choose between IPv4 and IPv6. All other parts get told to do one or the other. The other reason is that a probe on an IPv4-only LAN will not have an IPv6 default router. So any attempt to use the link local address to connect will remain hidden within the probe.