different behavior when I config static route for different IP route

[henrybb]

I do summary and static route for same ip subnet. But I got different result for different ip subnet.

I define ip summary on vlan 1 and add static ip route for same ip subnet.

I can't understand why 11.0.0.0/9 can't generate from " 0.0.0.0, from Rstatic", but 10.0.0.0/9 did it.

When will IOS redistribute static route to EIGRP automatilly which next hop is NULL 0 ?

Following is information from 6509 switch:

6509#sh ip eigrp to 11.0.0.0 255.128.0.0

IP-EIGRP (AS 1): Topology entry for 11.0.0.0/9

State is Passive, Query origin flag is 1, 1 Successor(s), FD is 3072

Routing Descriptor Blocks:

0.0.0.0 (Null0), from 0.0.0.0, Send flag is 0x0

Composite metric is (3072/0), Route is Internal

Vector metric:

Minimum bandwidth is 1000000 Kbit

Total delay is 20 microseconds

Reliability is 255/255

Load is 1/255

Minimum MTU is 1500

Hop count is 1

10.1.1.252 (Vlan1), from 10.1.1.252, Send flag is 0x0

Composite metric is (3584/3328), Route is Internal

Vector metric:

Minimum bandwidth is 1000000 Kbit

Total delay is 40 microseconds

Reliability is 255/255

Load is 3/255

Minimum MTU is 1500

Hop count is 3

6509#sh ip eigrp to 10.0.0.0 255.128.0.0

IP-EIGRP (AS 1): Topology entry for 10.0.0.0/9

State is Passive, Query origin flag is 1, 1 Successor(s), FD is 256

Routing Descriptor Blocks:

0.0.0.0, from Rstatic, Send flag is 0x0

Composite metric is (256/0), Route is Internal

Vector metric:

Minimum bandwidth is 10000000 Kbit

Total delay is 0 microseconds

Reliability is 0/255

Load is 0/255

Minimum MTU is 1500

Hop count is 0

10.1.1.252 (Vlan1), from 10.1.1.252, Send flag is 0x0

Composite metric is (2816/256), Route is Internal

Vector metric:

Minimum bandwidth is 1000000 Kbit

Total delay is 10 microseconds

Reliability is 0/255

Load is 1/255

Minimum MTU is 1500

Hop count is 1

10.1.254.2 (GigabitEthernet5/1), from 10.1.254.2, Send flag is 0x0

Composite metric is (2816/256), Route is Internal

Vector metric:

Minimum bandwidth is 1000000 Kbit

Total delay is 10 microseconds

Reliability is 0/255

Load is 1/255

Minimum MTU is 1500

Hop count is 1

0.0.0.0 (Null0), from 0.0.0.0, Send flag is 0x0

Composite metric is (2816/0), Route is Internal

Vector metric:

Minimum bandwidth is 1000000 Kbit

Total delay is 10 microseconds

Reliability is 0/255

Load is 1/255

Minimum MTU is 1500

Hop count is 1

6509#sh ip route | i ul

ia - IS-IS inter area, * - candidate default, U - per-user static route

S 11.0.0.0/9 is directly connected, Null0

S 11.128.0.0/9 is directly connected, Null0

S 10.0.0.0/9 is directly connected, Null0

S 10.128.0.0/9 is directly connected, Null0

6509#

6509#sh run | b router

router eigrp 1

passive-interface default

no passive-interface Vlan 1

no passive-interface GigabitEthernet5/1

network 10.0.0.0

no auto-summary

!

6509#sh run int vlan 1

Building configuration...

Current configuration : 276 bytes

!

interface Vlan1

ip address 10.1.1.251 255.255.255.0

ip summary-address eigrp 1 11.128.0.0 255.128.0.0 5

ip summary-address eigrp 1 11.0.0.0 255.128.0.0 5

ip summary-address eigrp 1 10.128.0.0 255.128.0.0 5

ip summary-address eigrp 1 10.0.0.0 255.128.0.0 5

end

[Richard Burts · Accepted solution]

Henry

I am not sure that I fully understand your question. But I understand enough to believe that I see the answer. The behavior is different because 10.0.0.0/9 and 10.128.0.0/9 match the network statement under your EIGRP process but 11.0.0.0/9 and 11.128.0.0/9 do not match any network statement under the EIGRP process.

HTH

Rick

[henrybb]

thanks for your reply.

But I can't understand your answer. Do you mean static routes to null 0 will automatically redistributed into EIGRP if I define "network 10.0.0.0 " under EIGRP ?

[pkhatri · Accepted solution]

That is correct. That is an interesting quirk of EIGRP where the network command will not only enable routing on interfaces that it covers, it will also inject matching static routes into the EIGRP topology table. I've also found that this latter behaviour is present only when the route points to an interface, and not when the static route points to a next-hop IP address.

Hope that helps - pls rate the post if it does.

Paresh

[kaviswanath]

when a static route is pointing to an interface , its looses its static nature and is considered as directly connected hence the observed behavior

Viswa