Control number of LSA in database

[katerina.dardoufa]

Hello community,

My company is running OSPF and we are in the process of migrating our remote sites to MPLS, but we seem to face the following problem. The provider has enabled max-LSA 400 on their PE. Our router is connected by fastethernet to the CPE which has the main line and ADSL backup. Our router still has an ISDN backup. When traffic is going through the main line everything is ok. If the main line fails, traffic goes through the ISDN backup instead of the ADSL backup, because the ISDN comes up faster. The size of the LSA database is then about 2500. If the ADSL or Serial come up then our router advertises this number of LSAs to the provider, which due to max LSA tears down the ospf neighborship between the PE and CPE. So there is no way that the traffic will eventually go through MPLS, unless someone manually tears down the ISDN call and clears the ospf process!

Is there a way to control the number of LSAs that come through the BRI and are then advertised to the providers PE?

Thanks in advance,

Katerina

[Jon Marshall · Accepted solution]

Katerina

What type of LSAs are they ?

Using area's and summarising between areas is the way to reduce your LSA count.

Jon

[katerina.dardoufa]

This is the output:

            OSPF Router with ID (192.168.1.111) (Process ID 1)

Area 11 database summary
  LSA Type           Count    Delete   Maxage
  Router                  31       0        0      
  Network                3        0        0      
  Summary Net        569      0        0      
  Summary ASBR    38       0        0      
  Type-7 Ext              0        0        0      
    Prefixes redistributed in Type-7  0
  Opaque Link           0        0        0      
  Opaque Area          0        0        0      
  Subtotal                641      0        0     

Process 1 database summary
  LSA Type           Count    Delete   Maxage
  Router                  31       0        0      
  Network                 3        0        0      
  Summary Net       569      0        0      
  Summary ASBR    38       0        0      
  Type-7 Ext             0        0        0      
  Opaque Link          0        0        0      
  Opaque Area         0        0        0      
  Type-5 Ext         1480     0        0      
   Prefixes redistributed in Type-5  0
  Opaque AS        0        0        0      
  Non-self      2120   
  Total         2121     0        0     

Unfortunately my router and the CPE are in the same area, so as I understand there is no way to control the number of LSAs if I keep them in the same area. I've got to think of something else...

Thanks for your answer. I think it cleared things up for me...