Flash Cards - OSPFv2

OSPF Packet Types (HD_RUA):

Type 1 - Hello / Type 2 - Database Descriptor / Type 3 - Link-State Request / Type 4 - Link-State Update / Type 5 - Link-State Acknowledgment.

OSPF uses protocol 89 - LSA Aging time 30 minutes / Can be changed: timers pacing lsa-group <Time in Minutes>

When you do a show ip ospf database network - The routing bit set means its a good route and in the RIB.

To inject a default route into OSPF, you need to have one configured already. Or you can use the command:

#Router ospf 1
#default-information originate always

If you are peering with non-cisco routers and having trouble. LLS is th ability to exchange vendor specific data within OSPF packets.

#Router ospf 1
#no capability lls (Link-local Signaling (LLS) support)

OR

intf#ip ospf lls disable
___________

P2P Sub-interfaces - Inverse ARP is disabled by default.

To change the default metric:

Router ospf 1
default-metric <#>

The default redistribution metric is <20>

#ip ospf flood-reduction (Sets the DoNotAge bit)

Hide the MPLS network when someone uses a traceroute:

#no mpls propogate-ttl

Router ospf 1
#max-metric router-lsa <on-startup | time | wait-for-bgp>
#redistribute maximum-prefix <#> <Threshold | warning-only>

OSPF Filtering

Type 1-2 LSA - On ABR

#area 1 range 10.1.1.0 255.255.255.0 <default is advertise> <not-advertise | cost>

#distribute-list 1 <route-map> in

Type 3 LSA - On ABR

#area 2 filter-list prefix <name> in

Type 5 - 7 - ASBR

#summary-address 10.1.1.1 255.255.255.0 <not-advertise>

#distribute-list 1 out