Hitachi GR2000 manual Router a Path to Ia is to be Learned by IG P Xterna l peer

4.7.8.1Cautions Regarding NextHop Resolution

When advertising paths to the BGP speaker in one and the same AS in this device, one’s own peering address used for peering with the BGP speaker is set in NEXT_HOP attributes. In addition, path data NEXT_HOP attributes received by the device are resolved based on the IGP path. There is therefore no need to set the other’s peering address in NEXT_HOP attributes and Next_Hop is resolved normally as long as the addressing path corresponding to NEXT_HOP attributes is learned by IGP. Designating the "resolve-nexthop all" option of the bgp command makes it possible to extend path data used in Next-Hop resolution to the IGP and BGP paths.

The about Next_Hop resolution processing applies to all peer types (external peers, peers between member ASs, internal peers).

	Router A
			Path to Ia is to be
	Ia		learned by IG P.
A S		E xterna l peer