OSPF. Unsolicited /32 prefixes on directly connected interfaces

Created: Feb 19, 2019 17:42:55Latest reply: Feb 22, 2019 10:18:26 167 3 0 0
  Rewarded Hi-coins: 0 (problem resolved)

HI here!

I'm configuring OSPF on my s6720 switch. It works, but it looks strange. I just turned OSPF on the interface, like this:

ospf 1 router-id

 silent-interface all

 undo silent-interface Vlanif4010



interface Vlanif4010

 ip address

 ospf cost 100

 ospf network-type p2mp

 ospf dr-priority 0


 mpls ldp

As you can see, all the neigbours have addresses in network. 

Then it started to discover the neighbours, and exchanged the routing info.  Finally I checked my RIB and found a lot of prefixes like this: 10.8.3.XX/32

Why the OSPF process generates /32 for directly connected interface. It isn't a Loopback interface, just usual vlan with broadcast network there. 

I tried to change network type, but it didn't change the behaviour. Probaly it could be connected with MPLS on the interface, who knows? 

Any way, could you give me a hint how i could change this behaviour? I applied a prefix list to filter these prefixes, but I don't think this is a good resolution of the problem.

  • x
  • convention:

Scott_Qing     Created Feb 21, 2019 14:26:13 Helpful(0) Helpful(0)

in p2mp network, ospf will create a host route for each neighbor, that is what you said 10.8.3.x/32 routes.
  • x
  • convention:

sim_157     Created Feb 20, 2019 14:48:41 Helpful(0) Helpful(0)

can you provide more details about your network topology and the routing-table?
  • x
  • convention:

chenhui  Addict   Created Feb 22, 2019 10:18:26 Helpful(0) Helpful(0)

as @Scott_Qing said, in p2mp network, ospf will generate host routes for ospf neighbors,
  • x
  • convention:


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