04-28-2009 07:25 AM - edited 03-04-2019 04:33 AM
This should be a fairly straight forward question to answer, but I can't seem to come up with a good answer. I have the following in my config:
vlan 181
name 106_Static_Routes
interface GigabitEthernet9/2
description 101, Gig2/6/1
switchport
switchport trunk encapsulation dot1q
switchport trunk allowed vlan 181,800-999
switchport mode trunk
no ip address
no snmp trap link-status
spanning-tree portfast disable
interface Vlan181
description To 101, Gig2/6/1
ip address 172.20.20.29 255.255.255.252
no ip redirects
no ip proxy-arp
ip pim sparse-mode
ip route 192.168.52.0 255.255.255.0 172.20.20.30
ip route 192.168.122.0 255.255.255.0 172.20.20.30
ip route 192.168.173.0 255.255.255.0 172.20.20.30
ip route 192.168.174.0 255.255.254.0 172.20.20.30
router eigrp 9
redistribute static metric 1000000 10 255 1 1500
passive-interface default
no passive-interface Serial1/1/0
no passive-interface Serial1/1/1
no passive-interface Serial1/1/2
no passive-interface GigabitEthernet5/1
no passive-interface GigabitEthernet5/2
no passive-interface GigabitEthernet6/1
no passive-interface GigabitEthernet7/5
no passive-interface GigabitEthernet7/6
no passive-interface GigabitEthernet7/7
no passive-interface GigabitEthernet8/23
no passive-interface GigabitEthernet9/22
network 10.18.0.0 0.0.127.255
network 172.20.0.0 0.0.127.255
no auto-summary
The problem is when interface g9/2 goes down, the static routes stay in the routing table and it blackholes traffic. I've tried clearing the routing table, but it stays.
I am running the following image:
s72033-ipservicesk9_wan-mz.122-18.SXF6.bin
Show inventory:
NAME: "5", DESCR: "WS-SUP720-3B 2 ports Supervisor Engine 720 Rev. 4.4"
PID: WS-SUP720-3B , VID: , SN:
NAME: "msfc sub-module of 5", DESCR: "WS-SUP720 MSFC3 Daughterboard Rev. 2.3"
PID: WS-SUP720 , VID: , SN:
NAME: "switching engine sub-module of 5", DESCR: "WS-F6K-PFC3B Policy Feature Card 3 Rev. 2.1"
PID: WS-F6K-PFC3B , VID: , SN:
04-28-2009 07:41 AM
Are you trying to have a failover in case an interface goes down?
HTH,
John
04-28-2009 07:45 AM
That will be our ultimate goal, but for now we are having the issue that the static route doesn't come out of the routing table when it is invalid. There are no other interfaces in the same subnet as the next hop IP, so we have to figure out why this is happening before we go any further towards any level of failover.
04-28-2009 07:45 AM
The problem is that Vlan181 remains up/up even when port G9/2 goes down. Make sure no other trunk or access port has Vlan181 in forwarding state.
Once you correct that problem, if G9/2 goes down (which should be the only switchport with Vlan 181 in forwarding state) then Vlan181 will go down hence removing the 172.20.20.28/30 connected route.
HTH,
__
Edison.
04-28-2009 07:48 AM
That is the only port on the switch that VLAN 181 is allowed on. When we noticed that the static route was in the table, we also verified that int vlan181 was down down.
04-28-2009 07:50 AM
Can you post the show ip route while the switchport G9/2 is down?
Also, show ip cef 172.20.20.30 det and show mls cef 172.20.20.30 det will help.
__
Edison.
04-29-2009 05:48 AM
Hi
The Gig port won't ever go down, neither the port nor the line protocol. (Except of-course someone pulls out the cable from the port)
So the static route won't ever get removed from the routing table. You will have to use keyword "track" with the static route. while configuring track you will have to configure rtr or ip sla (with appropriate timeout and frequeny values)depending upon ur IOS version.
Use the icmp echo option and the track will continuously monitor whether the other end /30 IP is reachable from your router or not. As soon as the other end becomes unreachable, the static route will get flushed out and what you desire shall happen.
URL:http://www.cisco.com/en/US/docs/ios/ipapp/command/reference/iap_s3.html
Just for your reference, a part of a config in one of my routers:
track 1 rtr 1 reachability
delay down 10 up 15
ip route 0.0.0.0 0.0.0.0 10.24.12.49 track 1
ip route 0.0.0.0 0.0.0.0 10.241.15.66 100
rtr 1
type echo protocol ipIcmpEcho 10.24.12.49 source-ipaddr 10.24.12.50
timeout 1500
frequency 5
rtr schedule 1 life forever start-time now
interface FastEthernet0/1.126
description *** 1 Mbps, Sify MPLS ***
bandwidth 1024
encapsulation dot1Q 126
ip address 10.24.12.50 255.255.255.252
no ip redirects
no ip unreachables
no ip proxy-arp
no ip mroute-cache
no cdp enable
crypto map XXXX
HTH
Vineet
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