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Nantu_Mandal_16's avatar
Nantu_Mandal_16
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Sep 15, 2014

Why "redistribute kernel" in OSPF configuration

Hi, I just check the OSPF configuration of my existing LTM. Can someone help to understand why "redistribute kernel" in OSPF configuration is used?

 

sh running-config

! no service password-encryption ! no banner motd ! interface lo ! interface tmm0 ! interface HA ! interface V700 ip ospf message-digest-key 1 md5 Nott4you ! interface V701 ! router ospf 1 ospf router-id 10.124.128.37 redistribute kernel redistribute connected route-map Allowed_Connected redistribute static passive-interface HA passive-interface V701 area 13 authentication message-digest network 10.124.128.32 0.0.0.15 area 13 ! ip route 10.124.136.0/24 Null ! access-list 1 permit 10.124.128.32 0.0.0.15 access-list 1 permit 10.124.128.16 0.0.0.15 ! route-map Allowed_Connected permit 1 match ip address 1 ! line con 0 login line vty 0 4 login ! end

 

  • according to this document:

     

    http://support.f5.com/kb/en-us/products/big-ip_ltm/manuals/product/tmos-ip-routing-administration-11-2-0/4.html

     

    it enables the sharing of the IPs of your virtual servers into OSPF.

     

  • Hi Nantu

     

    By default the dynamic routing protocol would redistribute connected interfaces on the F5 LTM. If you configure redistribute static, then the protocol would also advertise those static routes via dynamic protocol. However, the virtual server routes are neither connected nor static type. So, it falls under a new type known as kernel. That's why we need to redistribute kernel routes into the protocol for making the VS IP to be reachable from backbone.

     

    Regards,

     

    Sumanta.