SR OS routers never send or receive label-IPv6 routes with 32-bit IPv4 next-hop addresses.
When a label-IPv6 BGP route is advertised to an EBGP peer, next-hop-self command applies unless the EBGP session has next-hop-unchanged command enabled for the label-ipv6 address family. next-hop-self results in one of the following outcomes.
If the EBGP session uses IPv4 transport, then the BGP next-hop is taken from the value of the local address used to set up the session and encoded as an IPv4-mapped IPv6 address.
If the EBGP peer opened an IPv6 transport session and it is associated with an advertise-ipv6-next-hops label-ipv6 command then the BGP next-hop is set to the value of the IPv6 local address used for set up of the session. Otherwise, the BGP next-hop is set to the IPv4 address of the system interface encoded as an IPv4-mapped IPv6 address.
When a label-IPv6 BGP route is received from an EBGP peer and re-advertised to an IBGP or confederation EBGP peer, next-hop-self applies unless the IBGP or confederation EBGP session has the next-hop-unchanged command enabled for the label-IPv6 address family. The next-hop-self results in one of the following.
If the IBGP or confederation EBGP session uses IPv4 transport, then the BGP next-hop is taken from the value of the local address used to setup the session and encoded as an IPv4-mapped IPv6 address.
If the IBGP or confederation EBGP peer opened an IPv6 transport session and it is associated with an advertise-ipv6-next-hops label-ipv6 command then the BGP next-hop is set to the value of the IPv6 local address used for set up of the session. Otherwise, the BGP next-hop is set to the IPv4 address of the system interface encoded as an IPv4-mapped IPv6 address.