Invalid NEXT_HOP attribute for OSPF known route
Nico Schottelius
nico.schottelius at ungleich.ch
Tue Dec 14 20:35:48 CET 2021
Hello,
every year or then bird is putting me into the Invalid NEXT_HOP
message.
TL;DR:
Why does bird on router1+router2 refuse the route
2a0a:e5c0:0:12:b01a:5ae3:1bd4:1e00/122 via
2a0a:e5c0::225:90ff:fe1e:3e62
even though router1+router2 know how to reach 2a0a:e5c0::/64 via
fe80::20d:b9ff:fe57:2f91 by means of ospf?
In detail:
router1, router2 are peered to apu-router1,apu-router2 via OSPF + BGP.
apu-router1,apu-router2 are peered to a set of kubernetes hosts.
The goal is to have router1 + router2 import the routes sent by the
kubernetes hosts:
router1 router2---------|
| \ | |
| \ | |
| \ | |
apu-router1 apu-router2 |
. | . |
|--------------------------
. .
[ kubernetes cluster via apu-routers ]
The problem: router1+router reject the routes with:
Dec 14 20:33:51 router1 daemon.err bird: apu_router1_place5_ungleich_ch_v6: Invalid NEXT_HOP attribute
The setup:
router1, router2, apu-router1, apu-router2 = ASN209898
kubernetes hosts = ASN65533
kubernetes peers with apu-routers only.
The routes:
Kubernetes announces parts of 2a0a:e5c0:0:12::/64 and
2a0a:e5c0:0:13::/64, for instance the route
2a0a:e5c0:0:12:b01a:5ae3:1bd4:1e00/122.
Kubernetes nodes live in 2a0a:e5c0::/64.
apu-routers have a leg in 2a0a:e5c0::/64, via eth1.2. They reach the
cluster directly. They have the routes.
routers1+2 receive the route for 2a0a:e5c0::/64 via ospf:
bird> show route 2a0a:e5c0::/64
Table master6:
2a0a:e5c0::/64 unicast [ospf6 17:08:18.515] * I (150/20) [0.0.0.47]
via fe80::20d:b9ff:fe57:2f91 on bond0.8
Thus routers *can* reach the kubernetes cluster.
The apu-routers:
- They import the route [0]
- They export the route to the routers [1]
The routers:
- print 4x the Invalid NEXT_HOP attribute, once per exported
kubernetes network
- They ignore the 4 routes [2]
Question: why does bird on the routers not accept the routes? Or is
there a different problem I am not seeing? Aside from that, shouldn't
bird on the apu-routers set itself as nexthop for the kubernetes routes?
Any help appreciated.
Best regards,
Nico
[0]
[20:29] apu-router2.place5:~# birdc show route 2a0a:e5c0:0:12:b01a:5ae3:1bd4:1e00/122
BIRD 2.0.8 ready.
Table master6:
2a0a:e5c0:0:12:b01a:5ae3:1bd4:1e00/122 unicast [k8s_p5_1_4 19:16:10.910 from 2a0a:e5c0::225:90ff:fe1e:3e74] * (100) [AS65533i]
via 2a0a:e5c0::225:90ff:fe1e:3e62 on eth1.2
unicast [k8s_p5_1_3 19:16:10.910 from 2a0a:e5c0::225:90ff:fe1a:d680] (100) [AS65533i]
via 2a0a:e5c0::225:90ff:fe1e:3e62 on eth1.2
unicast [k8s_p5_1_5 19:16:10.909] (100) [AS65533i]
via 2a0a:e5c0::225:90ff:fe1e:3e62 on eth1.2
unicast [k8s_p5_1_1 19:16:10.910 from 2a0a:e5c0::225:90ff:fe1a:d682] (100) [AS65533i]
via 2a0a:e5c0::225:90ff:fe1e:3e62 on eth1.2
unicast [k8s_p5_1_2 19:16:10.910 from 2a0a:e5c0::225:90ff:fe1e:3e64] (100) [AS65533i]
via 2a0a:e5c0::225:90ff:fe1e:3e62 on eth1.2
unicast [k8s_p5_1_6 19:16:10.910 from 2a0a:e5c0::225:90ff:fe1e:62d6] (100) [AS65533i]
via 2a0a:e5c0::225:90ff:fe1e:3e62 on eth1.2
[20:42] apu-router2.place5:~#
[1]
[20:43] apu-router2.place5:~# birdc show protocol all router1_place5_ungleich_ch_v6
BIRD 2.0.8 ready.
Name Proto Table State Since Info
router1_place5_ungleich_ch_v6 BGP --- up 20:29:06.203 Established
BGP state: Established
Neighbor address: 2a0a:e5c0:1:8::3
Neighbor AS: 209898
Local AS: 209898
Neighbor ID: 147.78.195.249
Local capabilities
Multiprotocol
AF announced: ipv6
Route refresh
Graceful restart
4-octet AS numbers
Enhanced refresh
Long-lived graceful restart
Neighbor capabilities
Multiprotocol
AF announced: ipv6
Route refresh
Graceful restart
4-octet AS numbers
Enhanced refresh
Long-lived graceful restart
Session: internal AS4
Source address: 2a0a:e5c0:1:8::47
Hold timer: 175.206/240
Keepalive timer: 53.629/80
Channel ipv6
State: UP
Table: master6
Preference: 100
Input filter: REJECT
Output filter: ungleich_networks_no_igp
Routes: 0 imported, 6 exported, 0 preferred
Route change stats: received rejected filtered ignored accepted
Import updates: 98 0 98 0 0
Import withdraws: 3 0 --- 3 0
Export updates: 35 0 29 --- 6
Export withdraws: 0 --- --- --- 0
BGP Next hop: 2a0a:e5c0:1:8::47 fe80::20d:b9ff:fe49:a705
[2]
bird> show protocol all apu_router2_place5_ungleich_ch_v6
Name Proto Table State Since Info
apu_router2_place5_ungleich_ch_v6 BGP --- up 20:29:06.189 Established
BGP state: Established
Neighbor address: 2a0a:e5c0:1:8::47
Neighbor AS: 209898
Local AS: 209898
Neighbor ID: 0.0.0.47
Local capabilities
Multiprotocol
AF announced: ipv6
Route refresh
Graceful restart
4-octet AS numbers
Enhanced refresh
Long-lived graceful restart
Neighbor capabilities
Multiprotocol
AF announced: ipv6
Route refresh
Graceful restart
4-octet AS numbers
Enhanced refresh
Long-lived graceful restart
Session: internal AS4
Source address: 2a0a:e5c0:1:8::1
Hold timer: 157.409/240
Keepalive timer: 45.770/80
Channel ipv6
State: UP
Table: master6
Preference: 100
Input filter: ungleich_networks
Output filter: ungleich_networks_no_igp
Routes: 2 imported, 101 exported, 1 preferred
Route change stats: received rejected filtered ignored accepted
Import updates: 2 0 0 0 2
Import withdraws: 4 0 --- 4 0
Export updates: 140674 8 140565 --- 101
Export withdraws: 334 --- --- --- 0
BGP Next hop: 2a0a:e5c0:1:8::1 fe80::a236:9fff:fe08:a780
--
Sustainable and modern Infrastructures by ungleich.ch
More information about the Bird-users
mailing list