diff options
| author | Renato Westphal <renato@opensourcerouting.org> | 2021-10-07 23:45:31 -0300 |
|---|---|---|
| committer | Renato Westphal <renato@opensourcerouting.org> | 2021-10-08 09:13:37 -0300 |
| commit | ab6edbfeef365c7d598e5c171bfcc63687979129 (patch) | |
| tree | ed508be066e945548ec0f042c26662de1b6eac3f | |
| parent | 1c50c7243fee32d18b9f5fd0ab2380f850e3debc (diff) | |
ospfd: preserve DR status across graceful restarts
RFC 3623 says:
"If the restarting router determines that it was the Designated
Router on a given segment prior to the restart, it elects
itself as the Designated Router again. The restarting router
knows that it was the Designated Router if, while the
associated interface is in Waiting state, a Hello packet is
received from a neighbor listing the router as the Designated
Router".
Implement that logic when processing Hello messages to ensure DR
interfaces will preserve their DR status across a graceful restart.
Signed-off-by: Renato Westphal <renato@opensourcerouting.org>
| -rw-r--r-- | ospfd/ospf_packet.c | 15 |
1 files changed, 15 insertions, 0 deletions
diff --git a/ospfd/ospf_packet.c b/ospfd/ospf_packet.c index 1efdfee3b4..aa576d1452 100644 --- a/ospfd/ospf_packet.c +++ b/ospfd/ospf_packet.c @@ -1134,6 +1134,21 @@ static void ospf_hello(struct ip *iph, struct ospf_header *ospfh, nbr->priority = hello->priority; nbr->d_router = hello->d_router; nbr->bd_router = hello->bd_router; + + /* + * RFC 3623 - Section 2: + * "If the restarting router determines that it was the Designated + * Router on a given segment prior to the restart, it elects + * itself as the Designated Router again. The restarting router + * knows that it was the Designated Router if, while the + * associated interface is in Waiting state, a Hello packet is + * received from a neighbor listing the router as the Designated + * Router". + */ + if (oi->area->ospf->gr_info.restart_in_progress + && oi->state == ISM_Waiting + && IPV4_ADDR_SAME(&hello->d_router, &oi->address->u.prefix4)) + DR(oi) = hello->d_router; } /* Save DD flags/options/Seqnum received. */ |