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| author | ckishimo <carles.kishimoto@gmail.com> | 2020-09-17 11:51:26 +0200 |
|---|---|---|
| committer | ckishimo <carles.kishimoto@gmail.com> | 2020-09-17 16:44:14 +0200 |
| commit | 8273ee44487f1262291b48a92a37aa3bcf4abb2a (patch) | |
| tree | e208e37eefcbab04efe7e480ecbc801ee22a4d74 /ospfd | |
| parent | Merge pull request #7103 from opensourcerouting/sysrepo-fixes (diff) | |
| download | frr-8273ee44487f1262291b48a92a37aa3bcf4abb2a.tar.xz frr-8273ee44487f1262291b48a92a37aa3bcf4abb2a.zip | |
ospfd: do not generate type 4 LSA from NSSA ABR
In a topology like R1 -- R2 -- R5, with R2 being NSSA ABR and R5 being
ASBR redistributing external routes, the ABR R2 will translate type-7
LSA into type-5 and advertise to the backbone. In the current implementation
R2 is also advertising a type-4 LSA when there is no need.
RFC 3101: "...NSSA's border routers never originate Type-4 summary-LSAs
for the NSSA's AS boundary routers, since Type-7 AS-external-LSAs are
never flooded beyond the NSSA's border..."
With this PR a type-4 LSA will not be advertised
Signed-off-by: ckishimo <carles.kishimoto@gmail.com>
Diffstat (limited to 'ospfd')
| -rw-r--r-- | ospfd/ospf_abr.c | 9 |
1 files changed, 9 insertions, 0 deletions
diff --git a/ospfd/ospf_abr.c b/ospfd/ospf_abr.c index f6c050499..40a1ed3a8 100644 --- a/ospfd/ospf_abr.c +++ b/ospfd/ospf_abr.c @@ -1153,6 +1153,15 @@ static void ospf_abr_announce_rtr(struct ospf *ospf, struct prefix_ipv4 *p, if (ospf_abr_nexthops_belong_to_area(or, area)) continue; + /* RFC3101: Do not generate ASBR type 4 LSA if NSSA ABR */ + if (or->u.std.external_routing == OSPF_AREA_NSSA) { + if (IS_DEBUG_OSPF_EVENT) + zlog_debug( + "ospf_abr_announce_rtr(): do not generate LSA Type-4 %s from NSSA", + inet_ntoa(p->prefix)); + continue; + } + if (area->external_routing != OSPF_AREA_DEFAULT) { if (IS_DEBUG_OSPF_EVENT) zlog_debug( |