Description

When setting OSPF overload mode on a device, the external routes disappear in the OSPF routing table.

Symptoms

Before overload mode is set, the external route *0.0.0.0  maybe from the static/bgp/isis/rip, and can be shown on the OSPF database:

MX# run show ospf database advertising-router 119.235.224.2

OSPF database, Area 0.0.0.0
Type ID Adv Rtr Seq Age Opt Cksum Len
Router *119.235.224.2 119.235.224.2 0x80000056 409 0x22 0xf28 156
OSPF AS SCOPE link state database
Type ID Adv Rtr Seq Age Opt Cksum Len
Extern *0.0.0.0 119.235.224.2 0x80000001 409 0x22 0xb834 36 <-- advertising external route from this device

After OSPF overload mode is set:

MX# show protocols ospf | display set
set protocols ospf overload 

MX> show ospf database advertising-router 119.235.224.2

OSPF database, Area 0.0.0.0
Type ID Adv Rtr Seq Age Opt Cksum Len
Router *119.235.224.2 119.235.224.2 0x80000055 347 0x22 0x25b 156

<--- nothing external route 

Solution

This is the expected behavior. It is in compliance with RFC 1765 OSPF Database Overflow .

Related Information