09-19-2013 03:44 PM - edited 03-04-2019 09:05 PM
Hey all,
I'm having a weird OSPF issue with a particular network I'm working on.
Pretty simple setup, 4 locations, 4 x 2911 routers connected via Metro E and all advertise a default route. All 4 sites have another router behind the 2911s. Main site is at 10.89.228.1 so I want it to be the default route. However, for all locations all the internal routers do not pick up 10.89.229.40 as the default. Instead the pick the router that's internal
4 routers:
SITE A- 10.89.228.40 **MAIN**
SITE B- 10.89.229.40 (here's where all the output below is from)
SITE C- 10.88.7.40
SITE D- 10.88.6.40
internal routers are at .40 at all locations
Now two questions... A. I thought that E2 routes are always prefered over E1 routes.. this is not what I'm seeing here: see exhibit A
B. I thought that the default route with the lowest metric would be in the routing table - this is not what I'm seeing here either see exhibit B.
The output below comes from the internal router behind SITE B. So it has an ip address that's in the same LAN... 10.89.229.0/24
#sh ip os da ex 0.0.0.0 | i Metric|Adv|Typ
Type-5 AS External Link States
LS Type: AS External Link
Advertising Router: 10.88.6.40
Metric Type: 1 (Comparable directly to link state metric)
Metric: 10
LS Type: AS External Link
Advertising Router: 10.88.7.40
Metric Type: 1 (Comparable directly to link state metric)
Metric: 8
LS Type: AS External Link
Advertising Router: 10.89.228.40
Metric Type: 2 (Larger than any link state path)
Metric: 5
LS Type: AS External Link **THIS GETS IN THE ROUTING TABLE EVEN THOUGH METRIC TYPE ABOVE IS 2*
Advertising Router: 10.89.229.40
Metric Type: 1 (Comparable directly to link state metric)
Metric: 10
#sh ip os da ex 0.0.0.0 | i Ty|Ad|c:
Type-5 AS External Link States
LS Type: AS External Link
Advertising Router: 10.88.6.40
Metric Type: 1 (Comparable directly to link state metric)
Metric: 10
Forward Address: 0.0.0.0
LS Type: AS External Link
Advertising Router: 10.88.7.40
Metric Type: 1 (Comparable directly to link state metric)
Metric: 8
Forward Address: 0.0.0.0
LS Type: AS External Link
Advertising Router: 10.89.228.40
Metric Type: 1 (Comparable directly to link state metric)
Metric: 5
Forward Address: 0.0.0.0
LS Type: AS External Link
Advertising Router: 10.89.229.40 **THIS GETS IN THE ROUTING TABLE EVEN THOUGH 10>5**
Metric Type: 1 (Comparable directly to link state metric)
Metric: 10
Forward Address: 0.0.0.0
What am I missing? I thought I knew OSPF pretty well.. I guess I was mistaken.
thank you!
PS: I did clear ospf processes every time I was making changes..
09-19-2013 07:34 PM
Hi Anestis,
It would help if you could provide the unfiltered output for "sh ip os da ex 0.0.0.0".
Regards
09-20-2013 08:21 AM
Hi,
It would help if you could provide the unfiltered output for "sh ip os da ex 0.0.0.0".
... and the output of show ip ospf border-routers as well please.
Regards
Rolf
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