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Aspirant

Apr 28, 2020

Solved

IGMP Snooping filtering OSPF except on VLAN 1

Hello,

I am experiencing an issue where OSPF routers connectted m4300-series switches running IGMP Snooping are unable to form an adjacency. The m4300-series switches seem to be filtering OSPF multicast traffic (and possibly other traffic in 224.0.0.0/4 as well) which appears to be the cause of this issue.

I have a stack of 2x m4300-52g and 1x m4300-24x, a standalone m4300-24x, and a standalone m4300-12x12f that are all experiencing this issue.

I have observed this issue on firmware 12.0.11.10 and 12.0.11.8.

I do not recall observing this issue on older firmwares, but my network was much smaller and less complicated then.

Examining the routers, I can observe that they are all sending OSPF HELLO messages, but that they are not receiving messages from other routers.

Occasionally, I will see one router start to receive OSPF messages from other routers, but the other routers still do not see it's messages. This results in the router having a number of neighbors stuck in INIT, never forming a full or 2-way adjacency.

Examinging the MFDB Table on the switch, I can see a RSVD-MC STATIC entry for the important 01:00:5e:00:00:05 and 01:00:5e:00:00:06 groups. However, these entries only exist for VLAN 1. Examining the "forwarding interfaces" column of the MFDB Table, I observe that only ports participating in VLAN1 are in the list. For example, in the following table, ports 2/0/3 and 2/0/7 have OSPF routers which should be able to receive messages, but do not.

01:00:5e:00:00:05 	1 	RSVD-MC 	STATIC 	Network Assist 	1/0/7, 1/0/9 - 1/0/11, 1/0/13 - 1/0/16, 1/0/18 - 1/0/19, 1/0/22, 1/0/24 - 1/0/30, 1/0/32, 1/0/36, 1/0/41, 1/0/43 - 1/0/44, 2/0/5, 3/0/1 - 3/0/21, lag 1 - lag 2, lag 5, lag 7 - lag 9, lag 11 - lag 128
01:00:5e:00:00:06 	1 	RSVD-MC 	STATIC 	Network Assist 	1/0/7, 1/0/9 - 1/0/11, 1/0/13 - 1/0/16, 1/0/18 - 1/0/19, 1/0/22, 1/0/24 - 1/0/30, 1/0/32, 1/0/36, 1/0/41, 1/0/43 - 1/0/44, 2/0/5, 3/0/1 - 3/0/21, lag 1 - lag 2, lag 5, lag 7 - lag 9, lag 11 - lag 128
01:00:5e:00:00:09 	1 	RSVD-MC 	STATIC 	Network Assist 	1/0/7, 1/0/9 - 1/0/11, 1/0/13 - 1/0/16, 1/0/18 - 1/0/19, 1/0/22, 1/0/24 - 1/0/30, 1/0/32, 1/0/36, 1/0/41, 1/0/43 - 1/0/44, 2/0/5, 3/0/1 - 3/0/21, lag 1 - lag 2, lag 5, lag 7 - lag 9, lag 11 - lag 128
01:00:5e:00:00:12 	1 	RSVD-MC 	STATIC 	Network Assist 	1/0/7, 1/0/9 - 1/0/11, 1/0/13 - 1/0/16, 1/0/18 - 1/0/19, 1/0/22, 1/0/24 - 1/0/30, 1/0/32, 1/0/36, 1/0/41, 1/0/43 - 1/0/44, 2/0/5, 3/0/1 - 3/0/21, lag 1 - lag 2, lag 5, lag 7 - lag 9, lag 11 - lag 128
01:00:5e:00:00:6b 	1 	RSVD-MC 	STATIC 	Network Assist 	1/0/7, 1/0/9 - 1/0/11, 1/0/13 - 1/0/16, 1/0/18 - 1/0/19, 1/0/22, 1/0/24 - 1/0/30, 1/0/32, 1/0/36, 1/0/41, 1/0/43 - 1/0/44, 2/0/5, 3/0/1 - 3/0/21, lag 1 - lag 2, lag 5, lag 7 - lag 9, lag 11 - lag 128
01:00:5e:00:00:e6 	1 	RSVD-MC 	STATIC 	Network Assist 	1/0/7, 1/0/9 - 1/0/11, 1/0/13 - 1/0/16, 1/0/18 - 1/0/19, 1/0/22, 1/0/24 - 1/0/30, 1/0/32, 1/0/36, 1/0/41, 1/0/43 - 1/0/44, 2/0/5, 3/0/1 - 3/0/21, lag 1 - lag 2, lag 5, lag 7 - lag 9, lag 11 - lag 128
01:00:5e:00:00:e7 	1 	RSVD-MC 	STATIC 	Network Assist 	1/0/7, 1/0/9 - 1/0/11, 1/0/13 - 1/0/16, 1/0/18 - 1/0/19, 1/0/22, 1/0/24 - 1/0/30, 1/0/32, 1/0/36, 1/0/41, 1/0/43 - 1/0/44, 2/0/5, 3/0/1 - 3/0/21, lag 1 - lag 2, lag 5, lag 7 - lag 9, lag 11 - lag 128
01:00:5e:00:00:e8 	1 	RSVD-MC 	STATIC 	Network Assist 	1/0/7, 1/0/9 - 1/0/11, 1/0/13 - 1/0/16, 1/0/18 - 1/0/19, 1/0/22, 1/0/24 - 1/0/30, 1/0/32, 1/0/36, 1/0/41, 1/0/43 - 1/0/44, 2/0/5, 3/0/1 - 3/0/21, lag 1 - lag 2, lag 5, lag 7 - lag 9, lag 11 - lag 128
01:00:5e:00:00:e9 	1 	RSVD-MC 	STATIC 	Network Assist 	1/0/7, 1/0/9 - 1/0/11, 1/0/13 - 1/0/16, 1/0/18 - 1/0/19, 1/0/22, 1/0/24 - 1/0/30, 1/0/32, 1/0/36, 1/0/41, 1/0/43 - 1/0/44, 2/0/5, 3/0/1 - 3/0/21, lag 1 - lag 2, lag 5, lag 7 - lag 9, lag 11 - lag 128
01:00:5e:00:00:fb 	1 	RSVD-MC 	STATIC 	Network Assist 	1/0/7, 1/0/9 - 1/0/11, 1/0/13 - 1/0/16, 1/0/18 - 1/0/19, 1/0/22, 1/0/24 - 1/0/30, 1/0/32, 1/0/36, 1/0/41, 1/0/43 - 1/0/44, 2/0/5, 3/0/1 - 3/0/21, lag 1 - lag 2, lag 5, lag 7 - lag 9, lag 11 - lag 128
01:00:5e:00:00:fc 	1 	RSVD-MC 	STATIC 	Network Assist 	1/0/7, 1/0/9 - 1/0/11, 1/0/13 - 1/0/16, 1/0/18 - 1/0/19, 1/0/22, 1/0/24 - 1/0/30, 1/0/32, 1/0/36, 1/0/41, 1/0/43 - 1/0/44, 2/0/5, 3/0/1 - 3/0/21, lag 1 - lag 2, lag 5, lag 7 - lag 9, lag 11 - lag 128
01:00:5e:00:01:01 	1 	RSVD-MC 	STATIC 	Network Assist 	1/0/7, 1/0/9 - 1/0/11, 1/0/13 - 1/0/16, 1/0/18 - 1/0/19, 1/0/22, 1/0/24 - 1/0/30, 1/0/32, 1/0/36, 1/0/41, 1/0/43 - 1/0/44, 2/0/5, 3/0/1 - 3/0/21, lag 1 - lag 2, lag 5, lag 7 - lag 9, lag 11 - lag 128
01:00:5e:00:01:81 	1 	RSVD-MC 	STATIC 	Network Assist 	1/0/7, 1/0/9 - 1/0/11, 1/0/13 - 1/0/16, 1/0/18 - 1/0/19, 1/0/22, 1/0/24 - 1/0/30, 1/0/32, 1/0/36, 1/0/41, 1/0/43 - 1/0/44, 2/0/5, 3/0/1 - 3/0/21, lag 1 - lag 2, lag 5, lag 7 - lag 9, lag 11 - lag 128
01:00:5e:00:01:82 	1 	RSVD-MC 	STATIC 	Network Assist 	1/0/7, 1/0/9 - 1/0/11, 1/0/13 - 1/0/16, 1/0/18 - 1/0/19, 1/0/22, 1/0/24 - 1/0/30, 1/0/32, 1/0/36, 1/0/41, 1/0/43 - 1/0/44, 2/0/5, 3/0/1 - 3/0/21, lag 1 - lag 2, lag 5, lag 7 - lag 9, lag 11 - lag 128
01:00:5e:00:01:83 	1 	RSVD-MC 	STATIC 	Network Assist 	1/0/7, 1/0/9 - 1/0/11, 1/0/13 - 1/0/16, 1/0/18 - 1/0/19, 1/0/22, 1/0/24 - 1/0/30, 1/0/32, 1/0/36, 1/0/41, 1/0/43 - 1/0/44, 2/0/5, 3/0/1 - 3/0/21, lag 1 - lag 2, lag 5, lag 7 - lag 9, lag 11 - lag 128
01:00:5e:00:01:84 	1 	RSVD-MC 	STATIC 	Network Assist 	1/0/7, 1/0/9 - 1/0/11, 1/0/13 - 1/0/16, 1/0/18 - 1/0/19, 1/0/22, 1/0/24 - 1/0/30, 1/0/32, 1/0/36, 1/0/41, 1/0/43 - 1/0/44, 2/0/5, 3/0/1 - 3/0/21, lag 1 - lag 2, lag 5, lag 7 - lag 9, lag 11 - lag 128
01:00:5e:7f:ff:fa 	1 	RSVD-MC 	STATIC 	Network Assist 	1/0/7, 1/0/9 - 1/0/11, 1/0/13 - 1/0/16, 1/0/18 - 1/0/19, 1/0/22, 1/0/24 - 1/0/30, 1/0/32, 1/0/36, 1/0/41, 1/0/43 - 1/0/44, 2/0/5, 3/0/1 - 3/0/21, lag 1 - lag 2, lag 5, lag 7 - lag 9, lag 11 - lag 128
01:00:5e:7f:ff:fb 	1 	RSVD-MC 	STATIC 	Network Assist 	1/0/7, 1/0/9 - 1/0/11, 1/0/13 - 1/0/16, 1/0/18 - 1/0/19, 1/0/22, 1/0/24 - 1/0/30, 1/0/32, 1/0/36, 1/0/41, 1/0/43 - 1/0/44, 2/0/5, 3/0/1 - 3/0/21, lag 1 - lag 2, lag 5, lag 7 - lag 9, lag 11 - lag 128
01:00:5e:7f:ff:fc 	1 	RSVD-MC 	STATIC 	Network Assist 	1/0/7, 1/0/9 - 1/0/11, 1/0/13 - 1/0/16, 1/0/18 - 1/0/19, 1/0/22, 1/0/24 - 1/0/30, 1/0/32, 1/0/36, 1/0/41, 1/0/43 - 1/0/44, 2/0/5, 3/0/1 - 3/0/21, lag 1 - lag 2, lag 5, lag 7 - lag 9, lag 11 - lag 128
01:00:5e:7f:ff:fd 	1 	RSVD-MC 	STATIC 	Network Assist 	1/0/7, 1/0/9 - 1/0/11, 1/0/13 - 1/0/16, 1/0/18 - 1/0/19, 1/0/22, 1/0/24 - 1/0/30, 1/0/32, 1/0/36, 1/0/41, 1/0/43 - 1/0/44, 2/0/5, 3/0/1 - 3/0/21, lag 1 - lag 2, lag 5, lag 7 - lag 9, lag 11 - lag 128
01:00:5e:7f:ff:fe 	1 	RSVD-MC 	STATIC 	Network Assist 	1/0/7, 1/0/9 - 1/0/11, 1/0/13 - 1/0/16, 1/0/18 - 1/0/19, 1/0/22, 1/0/24 - 1/0/30, 1/0/32, 1/0/36, 1/0/41, 1/0/43 - 1/0/44, 2/0/5, 3/0/1 - 3/0/21, lag 1 - lag 2, lag 5, lag 7 - lag 9, lag 11 - lag 128
01:00:5e:7f:ff:ff 	1 	RSVD-MC 	STATIC 	Network Assist 	1/0/7, 1/0/9 - 1/0/11, 1/0/13 - 1/0/16, 1/0/18 - 1/0/19, 1/0/22, 1/0/24 - 1/0/30, 1/0/32, 1/0/36, 1/0/41, 1/0/43 - 1/0/44, 2/0/5, 3/0/1 - 3/0/21, lag 1 - lag 2, lag 5, lag 7 - lag 9, lag 11 - lag 128
91:e0:f0:01:00:00 	1 	RSVD-MC 	STATIC 	Network Assist 	1/0/7, 1/0/9 - 1/0/11, 1/0/13 - 1/0/16, 1/0/18 - 1/0/19, 1/0/22, 1/0/24 - 1/0/30, 1/0/32, 1/0/36, 1/0/41, 1/0/43 - 1/0/44, 2/0/5, 3/0/1 - 3/0/21, lag 1 - lag 2, lag 5, lag 7 - lag 9, lag 11 - lag 128

Aside from not forwarding OSPF traffic, IGMP Snooping does appear to work correctly on other VLANs. The switches correctly add and remove interfaces in response to IGMP Group Membership reports, and correctly identify mrouter ports where the routers are running PIM. Routers running PIM are able to form OSPF adjacencies with other OSPF routers running PIM, but not with any OSPF routers that are not mrouters. The querier election proceeds correctly and the correct querier is elected. Etc. etc.

I am temporarily working around this by disabling IGMP Snooping on certain VLANs where I have OSPF routers that are no mrouters, but this is not ideal, as I have >800 multicast groups running >2Gbps constantly. I have not yet explored the possibility of disabling IGMP Snooping only on the ports where I have OSPF routers that are not mrouters, but this would not be an ideal workaround either, as it would significantly increase configuration and management overhead, as well as increase the opportunity for human error in configuration.

In summary, it appears that IGMP Snooping on the m4300 series is incorrectly filtering OSPF traffic on VLANs other than VLAN 1. As a result, IGMP Snooping is only working correctly on VLAN 1, even if it otherwise works to control the flow of groups to ports.

Is this a firmware bug, or is there a configuration setting I have missed that controls this and allows other VLANs/ports to receive the RSVD-MC static entries? Or is this just a red herring and something else is configured incorrectly?

Thank you.

sdesigowda
Apr 30, 2020
In 12.0.11.x we introduced a new command 'set igmp-plus" which is needed for all reseved multicast addresses to work.
I beliveve following configuration should fix your issue

vlan database
vlan 20
set igmp-plus 20

11 Replies

Replies have been turned off for this discussion

schumaku
Guru
Apr 28, 2020
That's one for LaurentMa please.
- LaurentMa
  NETGEAR Expert
  Apr 28, 2020
  Thank you, schumaku
  
  Hi rgubele
  
  I am sorry for your issue, let's go and fix it. Kindy export the Tech-Support file out, you can simply go the web GUI, Maintenance \ Export \ HTTP File Export \ and select Tech Support at the end of the drop down menu list.
  
  You can use the private message here to let me know where I can get that file, and we'll be able to assess where is the problem.
  
  Thank you,
  - rgubele
    Aspirant
    Apr 29, 2020
    Hi LaurentMa ,
    
    I am working on obtaining the requested information for you. Thank you.
kevin_hong
Apprentice
Apr 29, 2020
Hi rgubele ,

Welcome to community,

I just tried a simple networking test to see how OSPF works except for vlan 1, It seems that OSPF neighbors can be set up normally on M4300 12.0.11.10.

I think I need more detailed information about your networking and configuration.

Could you please provide me with your topology and tech support file?

I'm going to try to replicate this issue.

Thank you.

(M4300-96X) #show ip ospf neighbor

Router ID Priority IP Address Neighbor State Dead
Interface Time
--------------- -------- --------------- ----------- ------------------ ----
192.168.20.2 1 192.168.20.2 vlan 20 Full/BACKUP-DR 34

My configuration as follow:
Topo
M4300---M4300

Interface vlan and OSPF configuration:
router ospf
router-id 192.168.20.2
interface vlan 20
routing
ip address 192.168.20.1 255.255.255.0
ip ospf area 0
exit
!
router ospf
router-id 192.168.20.1
interface vlan 20
routing
ip address 192.168.20.2 255.255.255.0
ip ospf area 0
exit

IGMP configuration:
vlan database
vlan 20
set igmp-plus 20

(M4300-96X) #show igmpsnooping

Admin Mode..................................... Enable
Multicast Control Frame Count.................. 2216
IGMP header validation......................... Enabled
Interfaces Enabled for IGMP Snooping........... None
VLANs enabled for IGMP snooping................ 1
20
Report Flood Mode.............................. Enabled
Exclude Mrouter Interface Mode................. Enabled
Operational Mode............................... Enable
Fast Leave Auto-Assignment Mode................ Enable
IGMP-Plus...................................... Enabled

VLAN ID........................................ 20
IGMP Snooping Admin Mode....................... Enabled
Fast Leave Mode................................ Enabled
Group Membership Interval (secs)............... 600
Max Response Time (secs)....................... 120
Multicast Router Expiry Time (secs)............ 300
Report Suppression Mode........................ Disabled
Report Flood Mode.............................. Enabled
Exclude Mrouter Interface Mode................. Enabled
IGMP-Plus...................................... Enabled

(M4300-96X) #show mac-address-table multicast

Fwd
VLAN ID MAC Address Source Type Description Interface Interface
------- ----------------- ------- ------- --------------- --------- ---------
20 01:00:5E:00:00:05 Rsvd-MC Static Network Assist Fwd: Fwd: ---- the ospf multicast address was in vlan 20
ALL ALL
20 01:00:5E:00:00:06 Rsvd-MC Static Network Assist Fwd: Fwd:
ALL ALL
- rgubele
  Aspirant
  Apr 29, 2020
  Hi kevin_hong ,
  
  Thank you for your reponse. My architecture is very complex at the moment, but a simplified version would be something like:
  
  [ROUTER] <-> [52G/24X stack] <-> [12x12f] <-> [ROUTER]
  
  Router could be:
  
  A Cisco device
  A Mikrotik device
  A Linux machine running Quagga (old and new versions)
  A Juniper device
  An Extreme/Brodcade device
  Whether a particular port is trunk or access, whether the vlan is tagged or not, doesn't seem to matter.
  
  Some notable differences I see in our configuration:
  
  We're not using IGMP-Plus mode. When I looked at it, it didn't appear to be appropriate for our configuration because we use any-source multicast and IGMPv2. IGMP Plus mode enables report flooding, which in theory should activate host report suppression and wouldn't work. Additionally, I have Exclude Mrouter Interface Mode disabled, and as nice as fast leave auto detection would be, I've disabled it because it doesn't seem to be reliable and I only need fast leave on a very small number of select reports.
  
  Also, we are using the switches as switches. I'm pretty sure we don't have any layer 3 features turned on, save for one routing interface we use as a management and monitoring IP. It's possible that using OSPF on the switch itself works and doesn't trigger this problem; I don't know.
  - kevin_hong
    Apprentice
    Apr 30, 2020
    Hi rgubele ,
    
    Thanks for your informations.
    
    I think we can do a simple test to verify the cause of the issue.
    
    Case#1: M4300-M4300 [52G/24X stack] <-> [12x12f] --- I've verified that it works
    
    Case#2: Cisco-M4300 --- Could you please verify this case ? (Routing vlan or IP routing interface)
    
    BTW:
    For M4300 the MTU was 9198 by default, So It affects protocol message processing with third party devices.
    I suggest you try changing the MTU to 1500 on M4300.(Make the MTU of both devices the same)
    
    For VLAN:
    (M4300-96X) (Config)#interface vlan 20
    (M4300-96X) (Interface vlan 20)#ip mtu 1500
    For Interface:
    (M4300-96X) (Config)#interface 1/1/1
    (M4300-96X) (Interface 1/1/1)#mtu 1500
    
    Thank you.