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Bigpaddy_Irl
join:2005-12-12
Ireland

Bigpaddy_Irl

Member

Routing publics over ospf network

Sorry guys, I know I brought this up before last year, but I still can not get my publics sorted over this OSPF network

To simplify things, I have
(MT R1)(MT R2)(MT R3)

MT R1 is running a BGP session with my upstream (works fine)
I have a /22 sitting here (works fine)

MT R2 has a public /24 on it, (works fine)

but
MT R3, when I put say a public /25 out of the original public /22 on it, MT R2 can ping it, but MT R1 can not.

When I tracert from a host machine one of the publics on MT R3, I keep getting replies from my upstream providers router and the lan ip of MT R1 router.

I believe there is some option under OSPF I am leaving out here???

Rhaas
Premium Member
join:2005-12-19
Bernie, MO

Rhaas

Premium Member

Can you post the output of '/routing ospf export' from router 1 & 3? (be sure to blank out your ospf key before posting)

On router 3, are you setting it to redistribute statically connected?
Bigpaddy_Irl
join:2005-12-12
Ireland

Bigpaddy_Irl

Member

Router 1

/routing ospf instance
set [ find default=yes ] distribute-default=if-installed-as-type-1 redistribute-connected=as-type-1
/routing ospf interface
add interface="ETHER_1 " network-type=broadcast
add disabled=yes network-type=broadcast
/routing ospf network
add area=backbone network=172.16.150.0/24
add area=backbone network=10.0.0.0/24
add area=backbone network=10.11.9.0/24
[admin@CORE NEP] >

Router 3

/routing ospf instance
set default disabled=no distribute-default=never in-filter=ospf-in metric-bgp=auto metric-connected=20 metric-default=1 metric-other-ospf=auto metric-rip=20 metric-static=\
20 name=default out-filter=ospf-out redistribute-bgp=no redistribute-connected=as-type-1 redistribute-other-ospf=no redistribute-rip=no redistribute-static=no \
router-id=10.255.255.7
/routing ospf area
set backbone area-id=0.0.0.0 disabled=no instance=default name=backbone type=default
/routing ospf network
add area=backbone disabled=no network=10.12.19.0/24
add area=backbone disabled=no network=10.12.85.0/24
add area=backbone disabled=no network=10.12.86.0/24
add area=backbone disabled=no network=10.12.70.0/24
add area=backbone disabled=no network=185.xxx.xx.0/24
add area=backbone disabled=no network=10.12.91.0/24

Rhaas
Premium Member
join:2005-12-19
Bernie, MO

Rhaas

Premium Member

Do you have that many interfaces on your router #3?

You only need a '/routing ospf network' entry for the interface you are running ospf on.

Is router 3 getting a default route?

Do you see the 185.x.x.0/24 in the routing table on routers 1 & 2?
Rhaas

Rhaas to Bigpaddy_Irl

Premium Member

to Bigpaddy_Irl
Click for full size
Simple config:

RT1:
/routing ospf instance
set [ find default=yes ] redistribute-connected=as-type-1 redistribute-static=as-type-1 router-id=loopback ip
/routing ospf interface
add authentication=md5 authentication-key=XXX cost=50 interface=TO_RT2 network-type=point-to-point
/routing ospf network
add area=backbone network=10.1.1.0/30

RT2:
/routing ospf instance
set [ find default=yes ] redistribute-connected=as-type-1 redistribute-static=as-type-1 router-id=loopback ip
/routing ospf interface
add authentication=md5 authentication-key=XXX cost=50 interface=TO_RT1 network-type=point-to-point
add authentication=md5 authentication-key=xyz cost=50 interface=TO_RT3 network-type=point-to-point
/routing ospf network
add area=backbone network=10.1.1.0/30
add area=backbone network=192.168.1.4/30

RT3:
/routing ospf instance
set [ find default=yes ] redistribute-connected=as-type-1 redistribute-static=as-type-1 router-id=loopback ip
/routing ospf interface
add authentication=md5 authentication-key=xyz cost=50 interface=TO_RT2 network-type=point-to-point
/routing ospf network
add area=backbone network=192.168.1.4/30


Depending on where and how your default route enters the network you may have to set one of the routers to redistribute the default route. Your network types may be different as well.
Bigpaddy_Irl
join:2005-12-12
Ireland

Bigpaddy_Irl to Rhaas

Member

to Rhaas
all those ip addresses are only on 2 interfaces, 3 of the subnets are on one interface. At the moment I have the 185.xxx.xx.0/24 on a loopback interface to see if I can ping it when I get it working.

I have a static route between all 3 routers so as to give me connectity to them.

I only see the 185.xxx.xx.0/24 subnet on routers 3 and 2, but not the DR router.
Bigpaddy_Irl

Bigpaddy_Irl

Member

I never bothered with setting up interfaces. Is this crucial?
Bigpaddy_Irl

Bigpaddy_Irl

Member

ok I have setup the interfaces as per your example and now in the logs I am getting discards.

Discarding packets: no neighbour with this source address

Rhaas
Premium Member
join:2005-12-19
Bernie, MO

Rhaas to Bigpaddy_Irl

Premium Member

to Bigpaddy_Irl
Click for full size
Click for full size
The interfaces are dynamically created based upon your entries under /routing ospf network

So that could be your problem because of the multiple entries you have for the networks on the same interface and they are dynamically created.

Do you see neighbor adjacencies?

What are the IP's you are using to link between the routers (like my first image)?
Rhaas

Rhaas to Bigpaddy_Irl

Premium Member

to Bigpaddy_Irl
said by Bigpaddy_Irl:

ok I have setup the interfaces as per your example and now in the logs I am getting discards.

Discarding packets: no neighbour with this source address

Sounds like the entries under /routing ospf network are incorrect.
Bigpaddy_Irl
join:2005-12-12
Ireland

Bigpaddy_Irl to Rhaas

Member

to Rhaas
I have only created the interfaces now seen as they were added in your example. When I remove them, dynamically they come up again.
Should I leave mine out?

ok router 1 is 10.11.9.1
router 2 is 10.11.9.10 WAN
router 2 is 10.12.19.1 LAN
router 3 is 10.12.19.2 WAN

Rhaas
Premium Member
join:2005-12-19
Bernie, MO

Rhaas

Premium Member

So under /routing ospf network on router 1 you would have 10.11.9.0/24, router 2 would have 10.11.9.0/24 and 10.11.19.0/24, router 3 would have 10.11.19.0/24
Bigpaddy_Irl
join:2005-12-12
Ireland

Bigpaddy_Irl

Member

that is correct

Rhaas
Premium Member
join:2005-12-19
Bernie, MO

Rhaas

Premium Member

When the interfaces are dynamically created are neighbor adjacencies being established?
Bigpaddy_Irl
join:2005-12-12
Ireland

Bigpaddy_Irl

Member

yes I can see all the neighbours being established, but in the logs its telling me its discarding them

Rhaas
Premium Member
join:2005-12-19
Bernie, MO

Rhaas

Premium Member

How are the routers connected to each other?
Bigpaddy_Irl
join:2005-12-12
Ireland

Bigpaddy_Irl

Member

router 1 and 2 are connected using a ceragon licenced link
router 2 and 3 are using a ligowave link

they have been like this for years using static routing

Rhaas
Premium Member
join:2005-12-19
Bernie, MO

Rhaas

Premium Member

Hmmmm. There has to be something I'm over looking..

What does your logs say exactly? Does it say what the source ip of the packet is that it is discarding?

I've been setting these up all the time here lately and never have trouble.
Bigpaddy_Irl
join:2005-12-12
Ireland

Bigpaddy_Irl

Member

2 errors are coming up

one error is....
Discarding Database Description Packet: Different MTU
mine = 1500
received = 1492

Rhaas
Premium Member
join:2005-12-19
Bernie, MO

Rhaas

Premium Member

said by Bigpaddy_Irl:

2 errors are coming up

one error is....
Discarding Database Description Packet: Different MTU
mine = 1500
received = 1492

Why do you have a 1492 MTU on any of the interfaces?
And which router is that error showing up?
Bigpaddy_Irl
join:2005-12-12
Ireland

Bigpaddy_Irl

Member

it wasn't meant intentionally
Bigpaddy_Irl

Bigpaddy_Irl to Rhaas

Member

to Rhaas
ospf is just after authenticating immediately once I changed it to 1500!
Bigpaddy_Irl

Bigpaddy_Irl

Member

only router 2 authenticated
router 3 is now telling me

Discarding Database Description Packet: Different MTU
mine = 1500
received = 1500

Rhaas
Premium Member
join:2005-12-19
Bernie, MO

Rhaas

Premium Member

So Router 1 & 2 have established neighbor adjacency?

Eh?! try to disable and re-enable the network under /routing ospf network to try to kick start ospf.
Bigpaddy_Irl
join:2005-12-12
Ireland

Bigpaddy_Irl

Member

tried that loads of times

Rhaas
Premium Member
join:2005-12-19
Bernie, MO

Rhaas

Premium Member

Tried rebooting the routers?

I have some meetings this morning but this afternoon I'll link up 3 routers and post the configs.
Bigpaddy_Irl
join:2005-12-12
Ireland

Bigpaddy_Irl

Member

Hi Rhaas,
After a few hours sleep last night I got up this morning and added nmba neighbours thinking the wireless links were the problem.
That didn't work, so I removed this config and low and behold the bloody thing started to work!!
This terrify's me as now I don't know what was really wrong :/

Inssomniak
The Glitch
Premium Member
join:2005-04-06
Cayuga, ON

Inssomniak

Premium Member

said by Bigpaddy_Irl:

Hi Rhaas,
After a few hours sleep last night I got up this morning and added nmba neighbours thinking the wireless links were the problem.
That didn't work, so I removed this config and low and behold the bloody thing started to work!!
This terrify's me as now I don't know what was really wrong :/

OSPF on mikrotik can do that. Rebooting helps to clear it out.
although its gotten better over the years once in a while a router will just simply go south, and never grab its neighbour.. rebooting fixes it.

Semaphore
Premium Member
join:2003-11-18
101010

Semaphore

Premium Member

+1 I use MT with OSPF from loopback IP's with NBMA everywhere and this happens very rarely. MT support did a bunch of dumps on this problem with me ~2 years ago. They could see the problem but they had no resolution. I'm pretty sure it's something stuck in the LSDB but don't know that for sure, and can't see anything that looks wrong.... It might happen once or twice a year.

Rhaas
Premium Member
join:2005-12-19
Bernie, MO

Rhaas

Premium Member

I've never used the nbma type, always point to point and have never had an issue.