OpenOSPF routing and CARP issues (?)

[Chris Naselli]

Hi all!
We are trying our two "edge" router (aging Cisco 7500 with ATM) with two
pairs of "carped" multi-function (firewalling/routing) OpenBSD boxes, both
for redundancy and for very advanced shaping/firewalling/bgp routing and
also due to future network upgrade to native METRO-Ethernet solution.

A sample schematic of the desiderata network schematic follows..

Location A
  O O O
  | | |
 ---
  em0||em0
 em2---[A1]  [A2]em2
  em1||em1
 --
   |
   | ISP Ethernet over MPLS service
   |
Location B   --
  em1||em1
 em2---[B1]  [B2]em2
  em0||em0
 --
  | | |
  O O O

Where:
- O are some small Cisco routers on some fiber-connected sites near our main
offices (A/B locations), speaking OSPF
- A1/A2 are OpenBSD routers in location A with all interface in carp mode.
- B1/B2 are OpenBSD routers in location B with all interface in carp mode.

I'm trying this configuration in laboratory, in order to check if everything
works fine and preparing the changeover, as I'm not a OpenBSD sysadmin
guru.. so I try to familiarize a bit with it. 

OpenOSPFD have the following configuration:

area 0.0.0.0 {
   interface em0  # carped with carp0
   interface em1  # carped with carp1
   interface carp2
}

In this topology I found a problem: OpenOSPF daemon is configured with
"interface carpX" for any interface with except em0/em1 to announce the
connected interface only if master but however there are the announce of all
the route learned from other cisco router behind it, thus causing (unwanted)
traffic also in the router in backup carp state.

How I can make OpenBSD redistribute ospf learned routes only if carp state
is master even if in ospfd.conf have configured "interface em0" (and not
"interface carp0")? Is my topology just broken?

Sorry for the long email and thanks in advance.

Best wishes,
Chris

-- 
View this message in context: 
http://www.nabble.com/OpenOSPF-routing-and-CARP-issues-%28-%29-tp18036287p18036287.html
Sent from the openbsd user - misc mailing list archive at Nabble.com.

Re: OpenOSPF routing and CARP issues (?)

[Claer]

On Fri, Jun 20 2008 at 48:12, Chris Naselli wrote:
> Hi all!
Hi,

[...]
> OpenOSPFD have the following configuration:
> 
> area 0.0.0.0 {
>interface em0  # carped with carp0
>interface em1  # carped with carp1
>interface carp2
> }
> 
> In this topology I found a problem: OpenOSPF daemon is configured with
> "interface carpX" for any interface with except em0/em1 to announce the
> connected interface only if master but however there are the announce of all
> the route learned from other cisco router behind it, thus causing (unwanted)
> traffic also in the router in backup carp state.
> 
> How I can make OpenBSD redistribute ospf learned routes only if carp state
> is master even if in ospfd.conf have configured "interface em0" (and not
> "interface carp0")? Is my topology just broken?
If you wish to execute commands (for example ospfd) regarding carp
states, I recommend you to check ifstated(8) and ifstated.conf(5)

> Sorry for the long email and thanks in advance.
Sorry I shortened it :)

Claer