# P2P on EVERY Vlan

**URL:** <https://forum.networklessons.com/t/p2p-on-every-vlan/2309>\
**Category:** OSPF\
**Created:** [October 19, 2017, 8:44pm UTC](https://forum.networklessons.com/t/p2p-on-every-vlan/2309 "2017-10-19T20:44:52Z")\
**Posts on this page:** 2\
**Page:** 1

<div class="post-metadata">

**Author:** ![shannen247](https://cdn-forum.networklessons.com/letter_avatar_proxy/v4/letter/s/e47c2d/32.png) [@shannen247](https://forum.networklessons.com/u/shannen247)\
**Post date:** [October 19, 2017, 8:44pm UTC](https://forum.networklessons.com/t/p2p-on-every-vlan/2309/1 "2017-10-19T20:44:52Z")

</div>

Anyone please help!!! The engineer before me configures ip ospf network point-to-point on every VLAN on every router and switch. I have never seen this type of configuration implemented. Granted we are working heavily with multicast but I dont think P2P Vlan effect multicast. Anyway, can anyone explain why would you need to configure every VLAN P2P.

example config: (this is done on every VLAN)

```
interface vlan xxx
ip addresss 198.168.17.x 255.255.255.252
ip pim sparse-mode
ip igmp version 3
ip ospf network point-to-point
ip ospf dead-interval 13
ip ospf hello-interval 1
ip ospf area 1

```

---

<div class="post-metadata">

**Author:** ![ReneMolenaar](https://cdn-forum.networklessons.com/user_avatar/forum.networklessons.com/renemolenaar/32/488_2.png) [@ReneMolenaar](https://forum.networklessons.com/u/ReneMolenaar)\
**Post date:** [October 27, 2017, 12:24pm UTC](https://forum.networklessons.com/t/p2p-on-every-vlan/2309/2 "2017-10-27T12:24:30Z")

</div>

The only reason I can think of is if you only have two OSPF routers within the VLAN. Still, there is no good reason to switch to point-to-point instead of the default (broadcast) on multi-access networks like a VLAN. With two OSPF routers, this will work. As soon as you add a third OSPF router, you will see flapping neighbor adjacencies.