OSPF and Static routes convergence

OSPF and Static routes convergence
NewsGroups | Search | Tools
User Password
Register Now! Lost Password?
 comp.dcom.sys.cisco  Post an article  get this group's latest topics as an RSS feed add this group's latest topics to your My MSN content add this group's latest topics to your My Yahoo content  add this group's latest topics to your Google content  YahooMyWeb Yahoo!  Google Google  Windows Live Favorites Windows Live  del.icio.us del.icio.us  digg digg  Add to Netscape Netscape
Subject Author Date
OSPF and Static routes convergence maher 12-21-2004
Posted by maher on December 21, 2004, 11:16 pm
If you were  Registered and logged in, you could reply and use other advanced thread options
Hi there,

My network is running OSPF and static route for ISDN connection for each
sites. Basically, I have redundancy whereby when the primary link is
down at site(s), ISDN connection will take over, and when the primary
link is back in action again, the ISDN will disconnect automatically.
This is the config under router ospf and static routes:

!
router ospf 100
log-adjacency-changes
network 10.0.0.0 0.0.0.255 area 0
!
ip route 192.168.0.0 255.255.255.0 172.168.1.1 150
ip route 192.168.1.0 255.255.255.0 172.168.1.2 150
ip route 192.168.2.0 255.255.255.0 172.168.1.3 150
!

From my understanding, when the routes see ospf, it will prefer to use
ospf rather than static becuase the static route AD is 150 compared to
OSPF 110.

However, due to some changes made by my college, I noticed that under
router ospf 100, there is command "redistribute static subnet"

!
router ospf 100
log-adjacency-changes
redistribute static subnet
network 10.0.0.0 0.0.0.255 area 0
!
ip route 192.168.0.0 255.255.255.0 172.168.1.1 150
ip route 192.168.1.0 255.255.255.0 172.168.1.2 150
ip route 192.168.2.0 255.255.255.0 172.168.1.3 150

From this config, when the primary link down, ISDN will take over but
when is primary is back online, it still prefer the routes for static.
For such, I need to clear static routes for each site(s) connected.

It seems that the routes is still prefer to use static routes.It is
because of the command or the AD in static routes defined?

thanks in advance.

maher


Pure Networks
Posted by Ben on December 22, 2004, 9:18 am
If you were  Registered and logged in, you could reply and use other advanced thread options
maher wrote:
> Hi there,
>
> My network is running OSPF and static route for ISDN connection for each
> sites. Basically, I have redundancy whereby when the primary link is
> down at site(s), ISDN connection will take over, and when the primary
> link is back in action again, the ISDN will disconnect automatically.
> This is the config under router ospf and static routes:
>
> !
> router ospf 100
> log-adjacency-changes
> network 10.0.0.0 0.0.0.255 area 0
> !
> ip route 192.168.0.0 255.255.255.0 172.168.1.1 150
> ip route 192.168.1.0 255.255.255.0 172.168.1.2 150
> ip route 192.168.2.0 255.255.255.0 172.168.1.3 150
> !
>
> From my understanding, when the routes see ospf, it will prefer to use
> ospf rather than static becuase the static route AD is 150 compared to
> OSPF 110.
>
> However, due to some changes made by my college, I noticed that under
> router ospf 100, there is command "redistribute static subnet"
>
> !
> router ospf 100
> log-adjacency-changes
> redistribute static subnet
> network 10.0.0.0 0.0.0.255 area 0
> !
> ip route 192.168.0.0 255.255.255.0 172.168.1.1 150
> ip route 192.168.1.0 255.255.255.0 172.168.1.2 150
> ip route 192.168.2.0 255.255.255.0 172.168.1.3 150
>
> From this config, when the primary link down, ISDN will take over but
> when is primary is back online, it still prefer the routes for static.
> For such, I need to clear static routes for each site(s) connected.
>
> It seems that the routes is still prefer to use static routes.It is
> because of the command or the AD in static routes defined?
>
> thanks in advance.
>
> maher

Hi Maher,

Is the administrative distance of 150 being carried into OSPF? (show ip
route when the ISDN links are active)

Ben


Posted by JNCIP#0136 on December 22, 2004, 10:17 pm
If you were  Registered and logged in, you could reply and use other advanced thread options
Hello,

Is Your next-hop 172.168.1.1 by any chance indirect and therefore being
resolved via OSPF when primary link is back UP?
I would suggest to nail down the static route by telling the router that
next-hop needs to be resolved via BRI/Dialer interface only:
ip route 192.168.0.0 255.255.255.0 Dialer0 172.168.1.1 150
For more info see http://www.cisco.com/warp/public/105/ip_static_routes.html
HTH,
Cheers
Alex

> Hi there,
>
> My network is running OSPF and static route for ISDN connection for each
> sites. Basically, I have redundancy whereby when the primary link is
> down at site(s), ISDN connection will take over, and when the primary
> link is back in action again, the ISDN will disconnect automatically.
> This is the config under router ospf and static routes:
>
> !
> router ospf 100
> log-adjacency-changes
> network 10.0.0.0 0.0.0.255 area 0
> !
> ip route 192.168.0.0 255.255.255.0 172.168.1.1 150
> ip route 192.168.1.0 255.255.255.0 172.168.1.2 150
> ip route 192.168.2.0 255.255.255.0 172.168.1.3 150
> !
>
> From my understanding, when the routes see ospf, it will prefer to use
> ospf rather than static becuase the static route AD is 150 compared to
> OSPF 110.
>
> However, due to some changes made by my college, I noticed that under
> router ospf 100, there is command "redistribute static subnet"
>
> !
> router ospf 100
> log-adjacency-changes
> redistribute static subnet
> network 10.0.0.0 0.0.0.255 area 0
> !
> ip route 192.168.0.0 255.255.255.0 172.168.1.1 150
> ip route 192.168.1.0 255.255.255.0 172.168.1.2 150
> ip route 192.168.2.0 255.255.255.0 172.168.1.3 150
>
> From this config, when the primary link down, ISDN will take over but
> when is primary is back online, it still prefer the routes for static.
> For such, I need to clear static routes for each site(s) connected.
>
> It seems that the routes is still prefer to use static routes.It is
> because of the command or the AD in static routes defined?
>
> thanks in advance.
>
> maher




Posted by Ben on December 23, 2004, 1:48 am
If you were  Registered and logged in, you could reply and use other advanced thread options
JNCIP#0136 wrote:
> Hello,
>
> Is Your next-hop 172.168.1.1 by any chance indirect and therefore being
> resolved via OSPF when primary link is back UP?
> I would suggest to nail down the static route by telling the router that
> next-hop needs to be resolved via BRI/Dialer interface only:
> ip route 192.168.0.0 255.255.255.0 Dialer0 172.168.1.1 150
> For more info see http://www.cisco.com/warp/public/105/ip_static_routes.html
> HTH,
> Cheers
> Alex
>
>
>>Hi there,
>>
>>My network is running OSPF and static route for ISDN connection for each
>>sites. Basically, I have redundancy whereby when the primary link is
>>down at site(s), ISDN connection will take over, and when the primary
>>link is back in action again, the ISDN will disconnect automatically.
>>This is the config under router ospf and static routes:
>>
>>!
>>router ospf 100
>>log-adjacency-changes
>>network 10.0.0.0 0.0.0.255 area 0
>>!
>>ip route 192.168.0.0 255.255.255.0 172.168.1.1 150
>>ip route 192.168.1.0 255.255.255.0 172.168.1.2 150
>>ip route 192.168.2.0 255.255.255.0 172.168.1.3 150
>>!
>>
>> From my understanding, when the routes see ospf, it will prefer to use
>>ospf rather than static becuase the static route AD is 150 compared to
>>OSPF 110.
>>
>>However, due to some changes made by my college, I noticed that under
>>router ospf 100, there is command "redistribute static subnet"
>>
>>!
>>router ospf 100
>>log-adjacency-changes
>>redistribute static subnet
>>network 10.0.0.0 0.0.0.255 area 0
>>!
>>ip route 192.168.0.0 255.255.255.0 172.168.1.1 150
>>ip route 192.168.1.0 255.255.255.0 172.168.1.2 150
>>ip route 192.168.2.0 255.255.255.0 172.168.1.3 150
>>
>> From this config, when the primary link down, ISDN will take over but
>>when is primary is back online, it still prefer the routes for static.
>>For such, I need to clear static routes for each site(s) connected.
>>
>>It seems that the routes is still prefer to use static routes.It is
>>because of the command or the AD in static routes defined?
>>
>>thanks in advance.
>>
>>maher
>
>
>
That's a very good point


Similar ThreadsPosted
ospf and multiple static routes August 4, 2006, 1:39 pm
Set specific next-hops for OSPF routes redistributed from static July 13, 2007, 11:50 am
Influencing OSPF Routes March 21, 2006, 8:07 pm
Routes received by BGP and OSPF February 5, 2007, 11:48 am
How do I remove routes from the OSPF RIF table ? August 26, 2005, 11:20 am
OSPF routes not in routing table June 10, 2006, 1:07 am
OSPF O routes vs. redist connected (E2) October 2, 2006, 12:01 pm
standby ASA doesn't learn ospf routes May 30, 2007, 2:24 pm
need help with weighted two static routes and NAT November 16, 2004, 2:43 am
static routes on pix 506e September 13, 2007, 9:45 am

other useful resources:
The Federal Communications Commission (FCC)
Telecommunications Industry Association
Electronic and Software Security Products and Services
International Telecommunication Union

Custom CGI Perl and PHP programming by 1-Script.com

Contact Us | Privacy Policy
The site map in XML format XML site map