Hello,
depending on your router model, below are two sample configs, one without, and one with a dialer watch:
chat-script lte “” “AT!CALL1” TIMEOUT 60 “OK”
!
track 1 ip sla 1 reachability
delay down 10 up 20
!
ip dhcp excluded-address 192.168.1.1
!
ip dhcp pool LAN
network 192.168.1.0 255.255.255.0
default-router 192.168.1.1
dns-server 8.8.8.8 4.2.2.2
!
ip sla auto discovery
!
ip local policy route-map SLA_RM
!
ip sla 1
icmp-echo 8.8.8.8 source-interface GigabitEthernet0
frequency 10
!
ip sla schedule 1 life forever start-time now
!
interface GigabitEthernet0
description ISP
ip address dhcp
ip nat outside
duplex auto
speed auto
!
interface Vlan1
ip address 192.168.1.1 255.255.255.0
ip nat inside
ip virtual-reassembly in
!
interface Cellular0
ip address negotiated
ip nat outside
ip virtual-reassembly in
encapsulation slip
ip tcp adjust-mss 1000
dialer in-band
dialer string lte
dialer-group 1
async mode interactive
!
ip nat inside source route-map ISP_BACKUP interface Cellular0 overload
ip nat inside source route-map ISP_PRIMARY interface GigabitEthernet0 overload
!
ip route 0.0.0.0 0.0.0.0 GigabitEthernet0 track 1
ip route 0.0.0.0 0.0.0.0 Cellular0 10
!
access-list 100 permit ip 192.168.1.0 0.0.0.255 any
!
access-list 101 permit icmp any host 8.8.8.8 echo
!
route-map SLA_RM permit 10
match ip address 101
set ip next-hop GigabitEthernet0
set interface Null0
!
route-map ISP_PRIMARY permit 10
match ip address 100
match interface GigabitEthernet0
!
route-map ISP_BACKUP permit 10
match ip address 100
match interface Cellular0
!
dialer-list 1 protocol ip permit
!
event manager applet CLEAR_NAT
event syslog pattern “TRACKING-5-STATE”
action 1 cli command “enable”
action 2 cli command “clear ip nat translation forced”
action 3 cli command “exit”
With dialer watch (cellular always on)
chat-script lte “” “AT!CALL1” TIMEOUT 60 “OK”
!
track 1 ip sla 1 reachability
delay down 10 up 20
!
ip dhcp excluded-address 192.168.1.1
!
ip dhcp pool LAN
network 192.168.1.0 255.255.255.0
default-router 192.168.1.1
dns-server 8.8.8.8 4.2.2.2
!
ip sla auto discovery
!
ip local policy route-map SLA_RM
!
ip sla 1
icmp-echo 8.8.8.8 source-interface GigabitEthernet0
frequency 10
!
ip sla schedule 1 life forever start-time now
!
interface GigabitEthernet0
description ISP
ip address dhcp
ip nat outside
duplex auto
speed auto
!
interface Vlan1
ip address 192.168.1.1 255.255.255.0
ip nat inside
ip virtual-reassembly in
!
interface Cellular0
ip address negotiated
ip nat outside
ip virtual-reassembly in
encapsulation slip
ip tcp adjust-mss 1000
dialer in-band
dialer string lte
dialer watch-group 1
async mode interactive
!
ip nat inside source route-map ISP_BACKUP interface Cellular0 overload
ip nat inside source route-map ISP_PRIMARY interface GigabitEthernet0 overload
!
ip route 0.0.0.0 0.0.0.0 GigabitEthernet0 track 1
ip route 0.0.0.0 0.0.0.0 Cellular0 10
!
access-list 100 permit ip 192.168.1.0 0.0.0.255 any
!
access-list 101 permit icmp any host 8.8.8.8 echo
!
route-map SLA_RM permit 10
match ip address 101
set ip next-hop GigabitEthernet0
set interface Null0
!
route-map ISP_PRIMARY permit 10
match ip address 100
match interface GigabitEthernet0
!
route-map ISP_BACKUP permit 10
match ip address 100
match interface Cellular0
!
dialer watch-list 1 ip 5.6.7.8 0.0.0.0
dialer watch-list 1 delay route-check initial 60
dialer watch-list 1 delay connect 1
!
event manager applet CLEAR_NAT
event syslog pattern “TRACKING-5-STATE”
action 1 cli command “enable”
action 2 cli command “clear ip nat translation forced”
action 3 cli command “exit”
!
event manager applet CELL_UP
event track 1 state down
action 1.0 cli command “enable”
action 1.1 cli command “configure terminal”
action 1.2 cli command “interface Cellular0”
action 1.3 cli command “no shutdown”
action 1.4 cli command “end”
!
event manager applet CELL_DOWN
event track 1 state up
action 1.0 cli command “enable”
action 1.1 cli command “configure terminal”
action 1.2 cli command “interface Cellular0”
action 1.3 cli command “shutdown”
action 1.4 cli command “end”
