02-01-2019 02:24 AM - edited 03-01-2019 05:57 PM
Hi,
In a setup with a router 2901 and a L3 Switch C3750G (take a look at the image) both setup with OSPFv3 and assigned with both global unicast and link local addr. I can ping from the router to the switch and vice versa.
Debugging hello packets show that the router sends and receive hello packet from the switch, but the switch only sends hello packets, but don't receive any from the router.
Hope someone can help with the missing hello packets from the router to the switch.
Regards
sd
02-02-2019 02:57 PM
It would be helpful if we have the debug output on the L3 switch and the relevant configuration of both devices.
02-03-2019 02:21 PM
02-04-2019 09:22 AM
02-04-2019 01:45 PM
Hi Sergey,
Here are the requested show output, notice that the L3 switch is a c3750 running ios v 12.2 so instead of "show ospfv3 interface brief" the command "show ipv6 ospf interface brief" command is used.
R1#sh ipv int bri
Em0/0 [administratively down/down]
unassigned
GigabitEthernet0/0 [up/up]
FE80::3A0E:4DFF:FE7C:F8A0
2AYY:XXXX:0:3::2
GigabitEthernet0/1 [up/up]
FE80::1
2AYY:XXXX:2::1
R1#sh ospfv3 int bri
Interface PID Area AF Cost State Nbrs F/C
Gi0/1 10 0 ipv6 1 DR 0/1
R1#
R1#sh ipv ospf int bri
Interface PID Area Intf ID Cost State Nbrs F/C
Gi0/1 10 0 4 1 DR 0/1
S1#sh ipv int bri
Vlan1 [up/down]
unassigned
Vlan12 [up/up]
FE80::1
2AYY:XXXX:2:C::1
Vlan20 [up/up]
FE80::1
2AYY:XXXX:2:14::1
Vlan980 [up/up]
FE80::101
2AYY:XXXX:2::101
GigabitEthernet1/0/1 [down/down]
unassigned
GigabitEthernet1/0/2 [up/up]
unassigned
S1#sh ospfv3 int bri
^
% Invalid input detected at '^' marker.
S1#sh ipv ospf int bri
Interface PID Area Intf ID Cost State Nbrs F/C
Vl20 10 0 2088 1 DR 0/0
Vl12 10 0 2080 1 DR 0/0
Vl980 10 0 3048 1 DR 0/0
S1#
Regards,
se.dejbjerg
02-05-2019 01:53 AM
OK, thanks. Can you please also show the following output from S1:
show span vlan 980
and from both:
show ipv6 neighbor
02-05-2019 01:20 PM
Hi Sergey,
Here you have the requested info. For your info, all the STALE States change to REACH after a ping.
S1#sh span vla 980
VLAN0980
Spanning tree enabled protocol ieee
Root ID Priority 33748
Address 0013.1962.4a00
Cost 12
Port 28 (GigabitEthernet1/0/28)
Hello Time 2 sec Max Age 20 sec Forward Delay 15 sec
Bridge ID Priority 33748 (priority 32768 sys-id-ext 980)
Address 64d9.8981.8280
Hello Time 2 sec Max Age 20 sec Forward Delay 15 sec
Aging Time 300 sec
Interface Role Sts Cost Prio.Nbr Type
------------------- ---- --- --------- -------- --------------------------------
Gi1/0/2 Desg FWD 4 128.2 P2p
Gi1/0/15 Desg FWD 4 128.15 P2p
Gi1/0/16 Desg FWD 4 128.16 P2p
Gi1/0/17 Desg FWD 4 128.17 P2p
Gi1/0/18 Desg FWD 4 128.18 P2p
Gi1/0/24 Desg FWD 4 128.24 P2p
Gi1/0/28 Root FWD 4 128.28 P2p
S1#sh ipv nei
IPv6 Address Age Link-layer Addr State Interface
FE80::1 2 380e.4d7c.f8a1 STALE Vl980
2AYY:XXXX:2::1 1 380e.4d7c.f8a1 STALE Vl980
FE80::20C:29FF:FEB1:582D 7 000c.29b1.582d STALE Vl12
2AYY:XXXX:2:C:20C:29FF:FEB1:582D 7 000c.29b1.582d STALE Vl12
S-21-25-01#sh ipv nei
R1#sh span vla 980
Spanning tree instance for VLAN 980 does not exist.
R1#sh ipv nei
IPv6 Address Age Link-layer Addr State Interface
2AYY:XXXX:0:3::1 15 8071.1f4a.b94a STALE Gi0/0
FE80::8271:1F08:D74A:B94A 14 8071.1f4a.b94a STALE Gi0/0
2AYY:XXXX:2::101 3 64d9.8981.82ce STALE Gi0/1
FE80::101 4 64d9.8981.82ce STALE Gi0/1
R1#
02-06-2019 03:41 AM
All looks to be in order there. I would try to disable MLDP snooping on the switch and see if that helps.
02-06-2019 09:41 AM
Hi,
Sergey has a point. It might indeed be MLD snooping related. Can you try pinging FF02::5 from both sides.
Regards,
02-07-2019 07:22 AM
Hi Sergey and Harold,
Below you see the ping result of S1 to R1 and vice versa.
I can ping from the L3 switch to the router but not from the router to the L3 switch, that also matches with the fact that the router receives hello packets from the L3 switch but not vice versa.
S1#ping ff02::5
Output Interface: vla 980
Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to FF02::5, timeout is 2 seconds:
Packet sent with a source address of FE80::101%Vlan980
Reply to request 0 received from FE80::1, 0 ms
Reply to request 1 received from FE80::1, 0 ms
Reply to request 2 received from FE80::1, 0 ms
Reply to request 3 received from FE80::1, 0 ms
Reply to request 4 received from FE80::1, 0 ms
Success rate is 100 percent (5/5), round-trip min/avg/max = 0/0/0 ms
5 multicast replies and 0 errors.
S1#
R1#ping ff02::5
Output Interface: gigabitethernet0/1
Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to FF02::5, timeout is 2 seconds:
Packet sent with a source address of FE80::1%GigabitEthernet0/1
Request 0 timed out
Request 1 timed out
Request 2 timed out
Request 3 timed out
Request 4 timed out
Success rate is 0 percent (0/5)
0 multicast replies and 0 errors.
R1#
Regards
se.dejbjerg
02-07-2019 07:51 AM
Have you tried disabling MLD snooping on the L3 switch, as suggested by Sergey?
Regards,
02-07-2019 08:28 AM
Hi Harold
Just tried to disable MLD snooping on the L3 switch with the global config command "no ipv6 mld snooping" and to be sure "no ipv6 mld snooping vlan 980". But still no successful ping with ff02::5 from R1, and the L3 switch only sending hello packets.
Tomorrow I am planning on attaching a similar L3 switch to the vlan 980 and see how it will act with the existing L3 switch and the router, all three devices at the same time and two devices at a time.
Regards
se.dejbjerg
02-07-2019 01:49 PM
Can you please post the following output:
R1:
show ipv6 int GigabitEthernet0/1
S1:
show ipv6 int Vlan980
Regards,
02-07-2019 02:09 PM
Hi Harold,
Here you have the requested output:
R1#sh ipv int g0/1
GigabitEthernet0/1 is up, line protocol is up
IPv6 is enabled, link-local address is FE80::1
No Virtual link-local address(es):
Description: LAN
Global unicast address(es):
2AYY:XXXX:2::1, subnet is 2AYY:XXXX:2::/64
Joined group address(es):
FF02::1
FF02::2
FF02::5
FF02::6
FF02::1:FF00:1
MTU is 1500 bytes
ICMP error messages limited to one every 100 milliseconds
ICMP redirects are enabled
ICMP unreachables are sent
Input features: Common Flow Table Stile classification
Output features: Common Flow Table Stile Classification
ND DAD is enabled, number of DAD attempts: 1
ND reachable time is 30000 milliseconds (using 30000)
ND advertised reachable time is 0 (unspecified)
ND advertised retransmit interval is 0 (unspecified)
ND router advertisements are sent every 200 seconds
ND router advertisements live for 1800 seconds
ND advertised default router preference is Medium
Hosts use stateless autoconfig for addresses.
R1#
S1#sh ipv int vla 980
Vlan980 is up, line protocol is up
IPv6 is enabled, link-local address is FE80::101
No Virtual link-local address(es):
Description: LAN_to_Router
Global unicast address(es):
2AYY:XXXX:2::101, subnet is 2AYY:XXXX:2::/64
Joined group address(es):
FF02::1
FF02::2
FF02::5
FF02::6
FF02::1:FF00:101
MTU is 1500 bytes
ICMP error messages limited to one every 100 milliseconds
ICMP redirects are enabled
ICMP unreachables are sent
Output features: Check hwidb
ND DAD is enabled, number of DAD attempts: 1
ND reachable time is 30000 milliseconds (using 30000)
ND advertised reachable time is 0 (unspecified)
ND advertised retransmit interval is 0 (unspecified)
ND router advertisements are sent every 200 seconds
ND router advertisements live for 1800 seconds
ND advertised default router preference is Medium
Hosts use stateless autoconfig for addresses.
S1#
Regards,
se.dejbjerg
04-18-2019 10:37 AM - edited 04-18-2019 01:01 PM
both switch and router are time synchronized with NTP.
Attached are OSPFv3 info from both switch and router https://audacity.onl/ https://findmyiphone.onl/ https://origin.onl/
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