RE: [nv-l] OSPF route change detection

[Brian Kraftchick <Brian.Kraftchick@odfl.com>]

HA....Scott...haven't I seen you on TV....HA !  Thanks for the input...and specific answers.  You started to head, I think, in the direction of suggesting how we might accomplish this.  Again, all that I am after is getting some type of notification of exactly when our remote sights have "moved" to their backup connection (Nortel Contivity Extranet switches).  Essentially, our WAN is hub and spoke with the primary connection being Frame-relay using Nortel ARN's at the remote sights connected to the hub, a Nortel BLN, here at our corporate office.  The "hot" backup connection is a live Nortel Contivity Extranet device at the remote sights connected into a central Nortel Contivity Extranet device here at our corporate office using VPN.  At the remote sights, the primary device, the ARN, and the secondary device, the Nortel Contivity Extranet device "talk" to eachother using VRRP (similar to Cisco's HSRP) to notify one another when the LAN interface on the ARN drops.  When that happens, the Nortel device's LAN interface then "assumes" the LAN interface IP address of the ARN, communicates on his behalf, thus changing the route to that remote network on our BLN here at the corporate office.  The BLN and the Nortel Extranet device here at the corporate office are on either sides of a core Nortel Layer 3 switch.  So in the case of a remote sight failing over to it's backup connection into the corporate office....that core Layer3's route and "next hop" to that remote network will then change (OSPF) from the BLN to the Nortel Extranet device.  That change is what I need to detect.....either via traps to NetView.......or from polling, which I'd rather not do, as the goal is know as immediately as possible when that happens vs. waiting on the next poll. 

 

I apologize for the "problem" description vs. asking specific technical questions about NetView, but I figured with as much knowledge and experience with NetView as I see on this list, surely someone will know the direction I should go to accomplish this.

 

Thanks for everyone's help and to all contributors !!!!!

 

 

 

 -----Original Message-----
From: Barr, Scott [mailto:Scott_Barr@csgsystems.com]
Sent: Wednesday, October 15, 2003 4:42 PM
To: nv-l@lists.us.ibm.com
Subject: RE: [nv-l] OSPF route change detection

I would not recommend even trying that unless you have a VERY small network.

 

If I understand OSPF correctly, what is going to happen is that when a route change occurs, ALL routers in the OSPF area will reflect the route change. This would mean that as soon as the first router changes, the rest will begin to change and then basically you are duplicating your efforts across many routers.

 

OSPF route changes happen for LOTS of reasons. For instance, if a segment on the back of the router goes down, that triggers an ospf update. When a circuit in a redundant environment fails, that can trigger ospf updates, these happen all the time. Detecting route changes with NetView could get ugly.

 

It's not really an OSPF mib either, it's the IP route table that gets updated through either the OSPF process on the router or someone typing in a static route. There is not that I know of, an OSPF mib you can query, only the MIB-II IP mib. Here is a sample:

 

ip.ipRouteTable.ipRouteEntry.ipRouteNextHop.10.10.54.0 : IpAddress: 192.168.10.21

ip.ipRouteTable.ipRouteEntry.ipRouteNextHop.10.10.55.0 : IpAddress: 192.168.10.21

ip.ipRouteTable.ipRouteEntry.ipRouteNextHop.10.10.60.0 : IpAddress: 192.168.10.21

ip.ipRouteTable.ipRouteEntry.ipRouteNextHop.10.10.61.0 : IpAddress: 192.168.10.21

ip.ipRouteTable.ipRouteEntry.ipRouteNextHop.10.10.62.0 : IpAddress: 192.168.10.21

 

Whether it is OSPF or statically routed or EIGRP or RIP or whatever, it is this table that gets updated and the only way I can think of to track changes is to somehow store these routes locally and check them against the next update when you query the router's IP route table again. Also note that OSPF routing tables are significantly larger because they contain all known routes in the OSPF area. Proceed with caution here. Other comments welcomed since I am not a routing protocol guru, I just play one on TV.

 

-----Original Message-----
From: owner-nv-l-digest@lists.us.ibm.com [mailto:owner-nv-l-digest@lists.us.ibm.com]On Behalf Of Brian Kraftchick
Sent: Wednesday, October 15, 2003 3:01 PM
To: NVList (E-mail)
Subject: [nv-l] OSPF route change detection

Does anybody have a suggestion on what OID to query within an OSPF configured router to determine/notify when a route changes.  I am quite new to understanding the MIB world and Netview for that matter and have the task of setting up a notification system (using Netview as either a "poll"er or trap receiver, along with TEC) to notify our WAN dept. when routes change.  Any ideas ?

 

Thanks in advance !!!

 

Brian Kraftchick

Network Administrator

Old Dominion Freight Line

Ph: (336) 822-5938

Fax: (336) 822-5149

E-mail: brian.kraftchick@odfl.com

Web Site: www.odfl.com