Symptom

After path of auto-RP packets switches to ASR900 after some instability in the network, we have a problem with forwarding of auto-rp packets to device behind the ASR. Next devices receives auto-rp packets, but then suddenly stops and they are timeout. Then it starts to receive again, and then stops. So, we have kind of flapping of RP behind the ASR900. For example, we have ASR9K connected to ASR903 in next way: ASR9K -> ASR903 - > RP We receive auto-rp info initially: RP/0/RSP1/CPU0:LAB-ASR-9010-SE-02#show ip pim rp map Fri Aug 2 12:21:14.053 MSK PIM Group-to-RP Mappings Group(s) 224.0.1.39/32 RP 10.255.0.74 (?), v2 Info source: 10.255.0.74 (?), elected via autorp Uptime: 00:00:53, expires: 00:02:06 Group(s) 224.0.1.40/32 RP 10.255.0.74 (?), v2 Info source: 10.255.0.74 (?), elected via autorp Uptime: 00:00:53, expires: 00:02:06 Group(s) 234.10.10.10/32 RP 10.255.0.74 (?), v2 Info source: 10.255.0.74 (?), elected via autorp Uptime: 00:00:53, expires: 00:02:06 Group(s) 234.11.11.11/32 RP 10.255.0.74 (?), v2 Info source: 10.255.0.74 (?), elected via autorp Uptime: 00:00:53, expires: 00:02:06 Group(s) 224.1.1.0/24 RP 10.255.0.74 (?), v2 Info source: 10.255.0.74 (?), elected via autorp Uptime: 00:00:53, expires: 00:02:06 Group(s) 239.255.0.0/17 RP 10.255.0.74 (?), v2 Info source: 10.255.0.74 (?), elected via autorp Uptime: 00:00:53, expires: 00:02:06 RP/0/RSP1/CPU0:LAB-ASR-9010-SE-02#RP/0/RSP1/CPU0:Aug 2 12:21:20.217 : pim[1151]: AUTORP Received packet of len 50 from 10.255.0.74 on interface Lo30 for vrf ptr 0x105831d4 RP/0/RSP1/CPU0:Aug 2 12:21:20.217 : pim[1151]: AUTORP 234.11.11.11/32(Sparse) to 10.255.0.74 (holdtime 180) RP/0/RSP1/CPU0:Aug 2 12:21:20.217 : pim[1151]: AUTORP 234.10.10.10/32(Sparse) to 10.255.0.74 (holdtime 180) RP/0/RSP1/CPU0:Aug 2 12:21:20.217 : pim[1151]: AUTORP 224.0.1.39/32(Sparse) to 10.255.0.74 (holdtime 180) RP/0/RSP1/CPU0:Aug 2 12:21:20.217 : pim[1151]: AUTORP 224.0.1.40/32(Sparse) to 10.255.0.74 (holdtime 180) RP/0/RSP1/CPU0:Aug 2 12:21:20.217 : pim[1151]: AUTORP 224.1.1.0/24(Sparse) to 10.255.0.74 (holdtime 180) RP/0/RSP1/CPU0:Aug 2 12:21:20.217 : pim[1151]: AUTORP 239.255.0.0/17(Sparse) to 10.255.0.74 (holdtime 180) +++ It expires after some time: RP/0/RSP1/CPU0:LAB-ASR-9010-SE-02#sh pim rp mapping Wed Aug 2 11:36:15.179 MSK PIM Group-to-RP Mappings Group(s) 224.0.1.39/32 RP 10.255.0.74 (?), v2 Info source: 10.255.0.74 (?), elected via autorp Uptime: 00:04:59, expires: now Group(s) 224.0.1.40/32 RP 10.255.0.74 (?), v2 Info source: 10.255.0.74 (?), elected via autorp Uptime: 00:04:59, expires: now <-Router lost information of RP. Group(s) 234.10.10.10/32 RP 10.255.0.74 (?), v2 Info source: 10.255.0.74 (?), elected via autorp Uptime: 00:04:59, expires: now Group(s) 234.11.11.11/32 RP 10.255.0.74 (?), v2 Info source: 10.255.0.74 (?), elected via autorp Uptime: 00:04:59, expires: now Group(s) 224.1.1.0/24 RP 10.255.0.74 (?), v2 Info source: 10.255.0.74 (?), elected via autorp Uptime: 00:04:59, expires: now Group(s) 239.255.0.0/17 RP 10.255.0.74 (?), v2 Info source: 10.255.0.74 (?), elected via autorp Uptime: 00:04:59, expires: now RP/0/RSP1/CPU0:LAB-ASR-9010-SE-02#sh pim rp mapping Wed Aug 2 11:36:26.826 MSK PIM Group-to-RP Mappings RP/0/RSP1/CPU0:LAB-ASR-9010-SE-02# +++ Then it restored again and expired again, so we have flapping +++ On ASR900 (which is problematic) we always have RP information and it never lost. Next outputs collected during the issue: ASR903#show ip pim rp mapping PIM Group-to-RP Mappings Group(s) 224.1.1.0/24 RP 10.255.0.74 (?), v2 Info source: 10.255.0.74 (?), elected via Auto-RP Uptime: 04:21:57, expires: 00:02:05 Group(s) 234.10.10.10/32 RP 10.255.0.74 (?), v2 Info source: 10.255.0.74 (?), elected via Auto-RP Uptime: 04:21:57, expires: 00:02:06 Group(s) 234.11.11.11/32 RP 10.255.0.74 (?), v2 Info source: 10.255.0.74 (?), elected via Auto-RP Uptime: 04:21:57, expires: 00:02:06 Group(s) 239.255.0.0/17 RP 10.255.0.74 (?), v2 Info source: 10.255.0.74 (?), elected via Auto-RP Uptime: 04:21:57, expires: 00:02:07 At the same time on ASR9K: RP/0/RSP1/CPU0:LAB-ASR-9010-SE-02#sh pim rp mapping Fri Aug 2 13:55:05.867 MSK PIM Group-to-RP Mappings RP/0/RSP1/CPU0:LAB-ASR-9010-SE-02#

Conditions

Issue is observed with latest release: asr900rsp3-universalk9_npe.16.09.03.SPA.bin ASR900 connected to RP and has device behind it, which should receive auto-rp packets. No special config on ASR except of: ASR903#show run | i pim ip pim sparse-mode ip pim sparse-mode ip pim sparse-mode ip pim sparse-mode ip pim sparse-mode ip pim autorp listener

Workaround

ASR903(config)#no ip pim autorp listener ASR903(config)#ip pim autorp listener

Further Problem Description