[c-nsp] EIGRP Adversing Problem

[Jason Lixfeld]

On 26-Oct-04, at 1:59 PM, Oliver Boehmer ((oboehmer)) wrote:

> Jason Lixfeld <> wrote on Tuesday, October 26, 2004 7:38 PM:
>
>> Use the eigrp router passive-interface command.
>>
>> http://www.cisco.com/en/US/tech/tk365/tk207/
>> technologies_tech_note09186a0080093f0a.shtml
>
> passive-interface will only prevent an EIGRP adjacency being formed 
> over
> this link, the link address will still be advertised.. the only way to
> prevent this from happening was mentioned by Bruce earlier :

Right.  I thought there was some context missing from the original 
email so it was subject to some assumptions.  My assumption were sorta' 
like so:

!
interface Loopback6969
  ip address 169.254.0.1 255.255.255.0
!
interface Tunnel1
  ip address 192.168.0.5 255.255.255.252
  ip mtu 1416
  ip tcp adjust-mss 1376
  cdp enable
  tunnel source Ethernet0/0
  tunnel destination 1.1.1.1
  tunnel path-mtu-discovery
!
interface Tunnel2
  ip address 192.168.0.22 255.255.255.252
  ip mtu 1416
  ip tcp adjust-mss 1376
  cdp enable
  tunnel source Ethernet0/0
  tunnel destination 2.2.2.2
  tunnel path-mtu-discovery
!
interface Tunnel3
  ip address 192.168.0.1 255.255.255.252
  ip mtu 1416
  ip tcp adjust-mss 1376
  cdp enable
  tunnel source Ethernet0/0
  tunnel destination 3.3.3.3
  tunnel path-mtu-discovery
!
router eigrp 6969
  passive-interface default
  no passive-interface Tunnel1
  no passive-interface Tunnel2
  no passive-interface Tunnel3
  network 192.168.0.0
  network 192.168.100.0
  no auto-summary
!

169.254.0.0/24 is connected, but the interface is passive and it is not 
redistributed via connected.  Therefore, it is not redistributed 
period.  Problem solved, no?

My assumption was also that Mark was not trying to hide this prefix 
from some EIGRP routers, while advertising it to others.  If that was 
is in fact what he was implying, then you guys are right -- distribute 
lists are it.

>> Well, it depends.  You could adjust your "network" statements in EIGRP
> to
>> not include that network or subnetwork.  Or you could use
> distribute-lists
>> to filter it out.
>
> In halfway modern code (at least 12.2 and later, I think 12.1 as well)
> you can use "network <network> <wildcard>" to exactly specify the
> interfaces' addresses which you want to be covered by EIGRP.. works
> similar to the way you setup OSPF..

In the above scenario, had the statement network 169.254.0.0 been 
present in the configuration, the route would have been redistributed, 
regardless as to whether or not the interface was passive, but what 
about if redistribute connected was turned on?  You wouldn't need the 
network statement in that case, right?

> 	oli