Sorry, sent this off-list by mistake. Maria
On 13 January 2024 18:11:07 CET, Maria Matejka <maria.mate...@nic.cz> wrote: >Hello! > >This will be possible in version 3, maybe not fully automatic in the first >stable versions. There is some code (indirectly) enabling this, waiting for >some finishing touches amd merging. You may expect to have an opportunity to >test it with the next alpha version of BIRD 3. > >With BIRD 2, to some extent it may be also possible directly with the upcoming >prefix aggregation feature. Not yet available now. > >Maria > >On 13 January 2024 01:56:50 CET, Lukas Haase via Bird-users ><bird-users@network.cz> wrote: >>Hi, >> >>Is is somehow possible to export a larger prefix if one or more sub-prefixes >>(subnets) are exported ... but also remove that prefix if no smaller subnet >>exist any more? >> >>Example: As soon as 192.0.2.44/32 or 192.0.2.208/28 (or any other prefix >>inside 192.0.2.0/24) is exported via eBGP, also export prefix 192.0.2.0/24. >>If no sub-prefixes are left, also remove 192.0.2.0/24 from export. >> >>Background for my question is BGP. As is well known, the smallest prefix I >>can announce over eBGP is /24. I use bird as a border gateway and I announce >>various smaller prefixes via iBGP. The smaller prefixes will take precedence >>in my peering neighboring AS but the /24 is required to announce my network >>farther out. >> >>But why would I want that? Because there are actually two border gateways. If >>all internal links to one of these gateways breaks, the full subnet should >>not be announced any more (otherwise the traffic would be dropped). If at >>least one subnet is announced, I assume that the internal mesh is strong >>enough to find its way. >> >> >>Thanks, >>Luke >> >> > >-- >Maria Matejka (she/her) | BIRD Team Leader | CZ.NIC, z.s.p.o. -- Maria Matejka (she/her) | BIRD Team Leader | CZ.NIC, z.s.p.o.
