[j-nsp] SRX OSPF routing issue with 2 SPs

[John Center]

On 07/19/2011 11:09 AM, OBrien, Will wrote:
> I export the wan route into ospf. Then if the wan connection goes down, the route is removed from the ospf export.
> This will increase the number of updates, but on a small network the extra cpu required is fairly minimal.
>
> The trick is getting the route removed. I usually have a dynamic protocol like bgp for the wan links.
> For a static connection, you could use the equivalent of netscreen ip monitoring on the SRX. (Which I think is there now, but I haven't needed it.)
>
>
> On Jul 19, 2011, at 9:46 AM, John Center wrote:
>
>> Hi,
>>
>> I'm hoping someone can help me with a routing configuration issue.  I
>> have the following physical configuration:
>>
>>        Backbone Router
>> 	/	\
>> VLAN 416|	| VLAN 417
>> 	L2 Switch
>> 	    || VLAN 416&  417
>> 	    ||
>> 	SRX3400 Cluster
>>
>>
>> The backbone router&  the L2 switch has 2 WAN connections (VLAN 416&
>> 417) from 2 SPs.  The VLANs are trunked over a LAG connection from the
>> L2 switch to the SRX3400 cluster.  OSPF is being run in a stub area
>> between the backbone router&  the SRXs.  The backbone router does not
>> support BFD.
>>
>> My problem is, if one of the 2 WAN connections between the Backbone
>> router&  the L2 switch goes down, how do I prevent the SRX from still
>> sending traffic on both of the 2 VLAN connections?  OSPF on the SRX
>> knows that the neighbor has gone down.  I think I should be able to do
>> this via the routing table, but I'm not sure how to approach it.
>>
>> Any help would be greatly appreciated.
>>
>> Thanks.
>>
>> 	-John
>>
>> --
>> John Center
>> Villanova University
>> _______________________________________________
>> juniper-nsp mailing list juniper-nsp at puck.nether.net
>> https://puck.nether.net/mailman/listinfo/juniper-nsp
>
> Will O'Brien
> University of Missouri, DoIT DNPS
> Network Systems Analyst - Redacted
>
> obrienh at missouri.edu

Hi Will,

Thanks for responding.  Yeah, I think my problem is removing the static 
route from the table if the link goes down.  For now, I changed the 
preference on the static routes so that OSPF routes are preferred.  As 
long as OSPF is up between the SRX cluster & the backbone router, 
everything is working.  I was thinking that in order to get more 
granular than this, I'd have to put an IP address on the L2 switches & 
use BFD between the switches, router & cluster for static routes.  I 
need to upgrade the switch OS to do this, but I'm restricted to what I 
can change right now.

Thanks, again.

	-John


-- 
John Center
Villanova University