gnrc_rpl: nib route not updated when topology / DODAG changes #17327
Description
Description
This issue can happen with a mobile node, but it can also arise if the DODAG changes at run-time (e.g. with #14623)
Steps to reproduce the issue
Setup ZEP dispatcher
In dist/tools/zep_dispatch replace the example.topo with
A B
B C
C D
This constitutes a simple linear network.
Start the ZEP dispatcher with make run.
Setup border router
Start the gnrc_border_router with gnrc_rpl enabled:
USEMODULE=gnrc_rpl make -C examples/gnrc_border_router all term
You should see the node being added by the ZEP dispatcher
adding node BE:0E:CF:F0:51:F6:B4:98
and the border router receiving a prefix on it's downstream interface
Iface 7 HWaddr: 34:98 Channel: 26 NID: 0x23
Long HWaddr: BE:0E:CF:F0:51:F6:B4:98
L2-PDU:102 MTU:1280 HL:64 RTR
RTR_ADV 6LO IPHC
Source address length: 8
Link type: wireless
inet6 addr: fe80::bc0e:cff0:51f6:b498 scope: link VAL
inet6 addr: 2001:db8::bc0e:cff0:51f6:b498 scope: global VAL
inet6 group: ff02::2
inet6 group: ff02::1
inet6 group: ff02::1:fff6:b498
inet6 group: ff02::1a
Iface 6 HWaddr: 7A:37:FC:7D:1A:AF
L2-PDU:1500 MTU:1500 HL:64 RTR
Source address length: 6
Link type: wired
inet6 addr: fe80::7837:fcff:fe7d:1aaf scope: link VAL
inet6 addr: fe80::2 scope: link VAL
inet6 group: ff02::2
inet6 group: ff02::1
inet6 group: ff02::1:ff7d:1aaf
inet6 group: ff02::1:ff00:2
Setup mesh nodes
Start 3 mesh nodes and initialize RPL on interface 7
USE_ZEP=1 make -C examples/gnrc_networking all term
rpl init 7
You should see them being added in the dispatcher:
adding node E6:65:A3:09:F5:9A:D0:BC
adding node FE:1E:98:42:04:09:A1:73
adding node 66:4E:F1:F0:57:34:36:5E
If you have foren6 running you can observe the topology:
Verify that the last (or any) node in the line can ping the border router:
ping 2001:db8::bc0e:cff0:51f6:b498
12 bytes from 2001:db8::bc0e:cff0:51f6:b498: icmp_seq=0 ttl=62 rssi=24672 dBm time=1.504 ms
12 bytes from 2001:db8::bc0e:cff0:51f6:b498: icmp_seq=1 ttl=62 rssi=24672 dBm time=1.610 ms
12 bytes from 2001:db8::bc0e:cff0:51f6:b498: icmp_seq=2 ttl=62 rssi=24672 dBm time=1.304 ms
--- 2001:db8::bc0e:cff0:51f6:b498 PING statistics ---
3 packets transmitted, 3 packets received, 0% packet loss
round-trip min/avg/max = 1.304/1.472/1.610 ms
DODAG change
Next we change the topology and connect D directly to A:
A B
B C
A D
We have to re-start the ZEP dispatcher for this to take effect.
Expected results
All nodes can still reach the border router
Actual results
Even though node bc has accepted node 98 as it's parent, it is still trying to route packets via the now unreachable 73
rpl
instance table: [X]
parent table: [ ] [X] [ ]
instance [0 | Iface: 7 | mop: 2 | ocp: 0 | mhri: 256 | mri 0]
dodag [2001:db8::bc0e:cff0:51f6:b498 | R: 512 | OP: Router | PIO: on | TR(I=[8,20], k=10, c=1)]
parent [addr: fe80::bc0e:cff0:51f6:b498 | rank: 256]
nib route
2001:db8::/64 dev #7
2001:db8::fc1e:9842:409:a173/128 via fe80::fc1e:9842:409:a173 dev #7
2001:db8::644e:f1f0:5734:365e/128 via fe80::fc1e:9842:409:a173 dev #7
default* via fe80::bc0e:cff0:51f6:b498 dev #7
nib neigh
fe80::bc0e:cff0:51f6:b498 dev #7 lladdr BE:0E:CF:F0:51:F6:B4:98 router REACHABLE GC
ping 2001:db8::bc0e:cff0:51f6:b498
--- 2001:db8::bc0e:cff0:51f6:b498 PING statistics ---
3 packets transmitted, 0 packets received, 100% packet loss
Versions
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