vppinc
asked on
IP SLA usage
Hi all
I am trying to setup a 3G card in a router to automatically connect to our MPLS network if the serial interface dies. The cellular interface is setup as backup to the serial interface. To transfer proper EIGRP routes, I have to setup an MGRE tunnel, which I have. Sprint service drops all cellular connections when unknown traffic flows over the wireless connection, but I have to generate traffic to establish the cellular connection (So I cannot run a continous ping from an inside source without the MGRE tunnel established). When the serial interface goes down, the router loses all routes, therefore no traffic is attempted. In order to dial the cellular interface and then the MGRE tunnel to transfer EIGRP, I have to generate traffic by manually pinging the MGRE destination. I have a static host route as needed to this destination through the cellular interface.
So that long explanation is to show why I am asking this question.. I want an IP SLA process to "attempt" a constant ping to an address, sourced from the cellular interface, that then only works when the serial interface is down.
Here is my relavant config. I still have to manually ping to establish the MGRE tunnel and relevant connection, but once that occurs, everything works well and EIGRP allows all network connectivity. What am I missing to get the router to automatically ping the addresses when the cellular interface does come up?
router#sho run
Building configuration...
Current configuration : 2288 bytes
!
version 12.4
interface Tunnel0
bandwidth 10000
ip address 192.168.250.2 255.255.255.252
ip nhrp authentication MGRE
ip nhrp map 192.168.250.2 172.20.188.102
ip nhrp map multicast 172.20.188.102
ip nhrp network-id 192168250
ip nhrp holdtime 300
ip nhrp nhs 192.168.250.1
ip nhrp cache non-authoritative
tunnel source Cellular0/1/0
tunnel destination 172.20.188.102
tunnel key 100000
!
interface FastEthernet0/0
ip address 192.168.5.3 255.255.255.0
duplex auto
speed auto
!
interface Serial0/0/0
backup interface Cellular0/1/0
ip address 172.20.194.86 255.255.255.252
!
interface Cellular0/1/0
ip address negotiated
encapsulation ppp
dialer in-band
dialer idle-timeout 3600
dialer string cdma
dialer-group 1
async mode interactive
!
router eigrp 100
network 172.20.194.84 0.0.0.3
network 192.168.5.0
network 192.168.250.0 0.0.0.3
no auto-summary
!
ip route 172.20.188.102 255.255.255.255 Cellular0/1/0
!
!
ip sla 1
icmp-echo 172.20.188.102 source-interface Cellular0/1/0
frequency 10
ip sla schedule 1 life forever start-time now
access-list 1 permit any
dialer-list 1 protocol ip list 1
!
line 0/1/0
exec-timeout 0 0
script dialer cdma
login
modem InOut
no exec
transport input all
rxspeed 3100000
txspeed 1800000
I am trying to setup a 3G card in a router to automatically connect to our MPLS network if the serial interface dies. The cellular interface is setup as backup to the serial interface. To transfer proper EIGRP routes, I have to setup an MGRE tunnel, which I have. Sprint service drops all cellular connections when unknown traffic flows over the wireless connection, but I have to generate traffic to establish the cellular connection (So I cannot run a continous ping from an inside source without the MGRE tunnel established). When the serial interface goes down, the router loses all routes, therefore no traffic is attempted. In order to dial the cellular interface and then the MGRE tunnel to transfer EIGRP, I have to generate traffic by manually pinging the MGRE destination. I have a static host route as needed to this destination through the cellular interface.
So that long explanation is to show why I am asking this question.. I want an IP SLA process to "attempt" a constant ping to an address, sourced from the cellular interface, that then only works when the serial interface is down.
Here is my relavant config. I still have to manually ping to establish the MGRE tunnel and relevant connection, but once that occurs, everything works well and EIGRP allows all network connectivity. What am I missing to get the router to automatically ping the addresses when the cellular interface does come up?
router#sho run
Building configuration...
Current configuration : 2288 bytes
!
version 12.4
interface Tunnel0
bandwidth 10000
ip address 192.168.250.2 255.255.255.252
ip nhrp authentication MGRE
ip nhrp map 192.168.250.2 172.20.188.102
ip nhrp map multicast 172.20.188.102
ip nhrp network-id 192168250
ip nhrp holdtime 300
ip nhrp nhs 192.168.250.1
ip nhrp cache non-authoritative
tunnel source Cellular0/1/0
tunnel destination 172.20.188.102
tunnel key 100000
!
interface FastEthernet0/0
ip address 192.168.5.3 255.255.255.0
duplex auto
speed auto
!
interface Serial0/0/0
backup interface Cellular0/1/0
ip address 172.20.194.86 255.255.255.252
!
interface Cellular0/1/0
ip address negotiated
encapsulation ppp
dialer in-band
dialer idle-timeout 3600
dialer string cdma
dialer-group 1
async mode interactive
!
router eigrp 100
network 172.20.194.84 0.0.0.3
network 192.168.5.0
network 192.168.250.0 0.0.0.3
no auto-summary
!
ip route 172.20.188.102 255.255.255.255 Cellular0/1/0
!
!
ip sla 1
icmp-echo 172.20.188.102 source-interface Cellular0/1/0
frequency 10
ip sla schedule 1 life forever start-time now
access-list 1 permit any
dialer-list 1 protocol ip list 1
!
line 0/1/0
exec-timeout 0 0
script dialer cdma
login
modem InOut
no exec
transport input all
rxspeed 3100000
txspeed 1800000
ASKER
I contacted Cisco about this and they suggested the following configuration.
track 151 rtr 151 reachability
delay down 10 up 60
!
ip sla 151
icmp-echo 172.20.194.85 source-interface serial0/0/0
frequency 10
ip sla schedule 151 life forever start-time now
!
event manager applet bring-up-celluar
event track 151 state down
action 1 cli command "conf t"
action 2 cli command "ping 172.20.188.102"
action 3 cli command "end"
!
However, the track 151 rtr command fails at "rtr", and the event Manager command is not available. Any further assistance would be helpful.
track 151 rtr 151 reachability
delay down 10 up 60
!
ip sla 151
icmp-echo 172.20.194.85 source-interface serial0/0/0
frequency 10
ip sla schedule 151 life forever start-time now
!
event manager applet bring-up-celluar
event track 151 state down
action 1 cli command "conf t"
action 2 cli command "ping 172.20.188.102"
action 3 cli command "end"
!
However, the track 151 rtr command fails at "rtr", and the event Manager command is not available. Any further assistance would be helpful.
ASKER CERTIFIED SOLUTION
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- You're not tracking a route for SLA. Add an initial default route to your serial link that is tracked, then another to the cellular connection.
- Set the idle-timeout to 0
http://www.cisco.com/en/US/docs/routers/access/1800/1861/software/feature/guide/3ghwic.html#wp1178422