Hello list! Currently bird uses '0.0.0.0' network mask in OSPF hello messages for ptp links. This is (at least originally) done to catch possible misconfiguration at the other end. RFC 2328 sec 10.5 tells us that this is perfectly OK and network mask should be ignored for p2p and virtual links. However, Juniper interprets RFC more formally and their point is that Ethernet is not real point-to-point interface, so network mask is checked anyway. See http://kb.juniper.net/InfoCenter/index?page=content&id=KB23533 for more detailed explanation. This check kills bird ability to establish p2p link with Juniper boxes. Cisco and Huawei (at least some models) ignores netmask as they should, but sends real network mask in hello messages. Maybe it will be useful to make bird behavior configurable: patch adding 'real mask <switch>' interface option is attached.