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%OSPF-4-FLOOD_WAR messages after config change

aalbrecht27
Level 1
Level 1

I recently changed some configs on two L3 switches running OSPF.  After this change I'm now getting the below log message about ever 2 minutes or so on one of the switches (172.22.0.53):

%OSPF-4-FLOOD_WAR: Process 1 re-originates LSA ID 172.18.24.3 type-2 adv-rtr 172.22.0.53 in area 0

The two switches are using loopbacks 172.22.0.53 and 172.22.0.89, and are connected via a radio link.  Previously both switches were using Layer 3 vlan interfaces with their OSPF configs applied to those vlan interfaces, then the physical interfaces were added in this VLAN as a L2 interface.  The radio AP's were also within this vlan and not participating in OSPF.  Under this setup I was not getting these Flood War messages, but was having a spanning-tree issue which is why I removed the L3 vlan interfaces.

I changed the physical ports to routed ports and copied the L3 vlan interfaces over and removed the L3 vlans.  This is working, but now I'm getting these OSPF Flood war messages.  I didn't change any router ID's, and the IP's set on the L3 vlans were moved to the L3 routed ports so I'm not sure where the duplicate is coming from.  I've attached the configs of both switches.

Any ideas?

1 Accepted Solution

Accepted Solutions

acampbell
VIP Alumni
VIP Alumni

Hi

from url:-

http://www.cisco.com/c/en/us/support/docs/ip/open-shortest-path-first-ospf/9237-9.html

Q. What does the error message %OSPF-4-FLOOD_WAR: Process process-id re-originates LSA ID ip address type-2 adv-rtr ip address in area area id means?

 

A. The error message is due to the some router that is flushing the network LSA because the network LSA received by the router whose LSA ID conflicts with the IP address of one of the router's interfaces and flushes the LSA out of the network. For OSPF to function correctly the IP addresses of transit networks must be unique. If it is not unique the conflicting routers reports this error message. In the error message the router with the OSPF router ID reported as adv-rtr reports this message.

Also on your 53 config

 

You have a paasive int on vlan 153 but that SVI does not exist , 133 does though

 

Regards
Alex

Regards, Alex. Please rate useful posts.

View solution in original post

7 Replies 7

acampbell
VIP Alumni
VIP Alumni

Hi

from url:-

http://www.cisco.com/c/en/us/support/docs/ip/open-shortest-path-first-ospf/9237-9.html

Q. What does the error message %OSPF-4-FLOOD_WAR: Process process-id re-originates LSA ID ip address type-2 adv-rtr ip address in area area id means?

 

A. The error message is due to the some router that is flushing the network LSA because the network LSA received by the router whose LSA ID conflicts with the IP address of one of the router's interfaces and flushes the LSA out of the network. For OSPF to function correctly the IP addresses of transit networks must be unique. If it is not unique the conflicting routers reports this error message. In the error message the router with the OSPF router ID reported as adv-rtr reports this message.

Also on your 53 config

 

You have a paasive int on vlan 153 but that SVI does not exist , 133 does though

 

Regards
Alex

Regards, Alex. Please rate useful posts.

That's what I'm a bit confused on, the configs from the L3 vlan interfaces were simply moved to the physical ports, and then I removed the L3 vlans completely.  I've double checked the configs to make sure I didn't fat finger in the same IP on the physical interfaces but they are different - I'm not sure where the duplicate is coming from.

Hi,

On router 53

Try 

!
int loop 0
shut
!
end


Then try 
ping 172.22.0.53

If you get a !!! response
Then try to find the address 172.22.0.53
with trace and sh ip route 172.22.0.53

It may just be you need to alllocate a different loop 0
ip address on your 53 router.

Regards
Alex

Regards, Alex. Please rate useful posts.

If there was a duplicate IP then why weren't these log messages present before I made the config changes?  This will also cause a disruption in the network which I'm not really looking to do.

aalbrecht27
Level 1
Level 1

I found the duplicate IP address, it was on another switch as another L3 vlan but it wasn't even up.  The weird thing is that the switch sending these flood war messages had a power outage, and when it came back up it stopped sending the flood war messages.  The only reason I know for sure this is the cause is that I had 2 other switches doing the exact same thing and as soon as I removed the L3 vlan the flood war messages stopped on the other switch.

yang yang
Level 1
Level 1

I have go the some type problems . Say R1 —R2-R3.  R1 use RID10.10.0.1 and it got svu under this /24 subnet . R2 set RID 10.10.0.2 but do not have interface  for this subnet. And R3 set RID 10.20.0.1 have interface under this subnet. The result will be R2 will established neighbor full width of the R1 and R3 , R2 will learn route from R1 and R3, R2 will advertise R1 and self route to R3. But R2 will not advertise self and TO route to R1. And R1 RY both will have this flood error. Even under R1 no other device using 10.10.0.2.  I think it could be some thing to do with LSA messages identification logic.   And if you apply route id that is not the device interface ip but ospf instance have this Subnet and use one ip as RID  the LSA will not updated to the device that has this subnet .(this message Will play out).   If has an other devices use the router id then will have messages duplicate IP.    So conclusion is to  manual ospf router id  needs 1. No other devices using the IP that mean unique under ospf. 2.bast have interface Svi loopback all OK to own this ip. 3.  if assign route id ip subnet is not own by device interface and within ospf instance has other route adv and has same subnet different ip use as route id, the route opf map  will not pass between them. 

 

 If I change the R2 RID to 10.0.10.2 the ospf will work , or if R2 own an interface has IP 10.10.0.2/32 and advance in to ospf, and R1 do not have some length route for 10.10.0.2. the ospf will work.

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