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Help with Understanding Router Configuration

Hello Experts,

I have router configuration with the following setup.

The customer has leased line internet connection

Internet>>ISP Modem>> Customer Router

I have the router configured as follows. I am just trying a. What typed of configuration or technology playing a role ? b. How must have the ISP setup ?

ISP has provided the public ip address and how its routing to ISP.

hostname R1
!
boot-start-marker
boot-end-marker

mmi polling-interval 60
no mmi auto-configure
no mmi pvc
mmi snmp-timeout 180
no aaa new-model
ip subnet-zero
ip cef
!
!
!
!
ip name-server 4.2.2.2
ip name-server 8.8.8.8
ip ips po max-events 100

!

track 1 interface Tunnel0 line-protocol
!
track 2 interface Tunnel1 line-protocol
!
no crypto isakmp ccm
!

interface Tunnel0
 description Connection to ISP
 ip unnumbered FastEthernet0/0
 ip tcp adjust-mss 1400
 keepalive 10 3
 tunnel source 192.168.70.62
 tunnel destination 192.168.70.61
!
interface Tunnel1
 description Connection to ISP Wireless Backup
 ip unnumbered FastEthernet0/1
 ip tcp adjust-mss 1452
 keepalive 10 3
 tunnel source 192.168.73.58
 tunnel destination 192.168.73.57
!
interface FastEthernet0/0
 description *Connection to ISP Modem
 ip address 192.168.70.62 255.255.255.252
 ip nbar protocol-discovery
 load-interval 30
 speed 100
 full-duplex
!
interface FastEthernet0/1
 description *Connection to ISP Wireless
 ip address 192.168.73.58 255.255.255.252
 ip tcp adjust-mss 1452
 load-interval 30
 duplex auto
 speed auto
!
interface FastEthernet0/0/0
 load-interval 30
 duplex full
 speed 100
!
interface FastEthernet0/0/1
 duplex full
 speed 100
!
interface FastEthernet0/0/2
!
interface FastEthernet0/0/3
!
interface Vlan1
 description $ES_LAN$
 ip address 1.1.1.1 255.255.255.248
 ip tcp adjust-mss 1400
!
interface Dialer0
 no ip address
!
ip classless
ip route 0.0.0.0 0.0.0.0 192.168.70.61 track 1
ip route 0.0.0.0 0.0.0.0 192.168.73.57 100 track 2


end

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Please can someone help in understand this scenario.

Thanks

Miftaul H

a. What typed of configuration or technology playing a role ?
Your router seems to be connected to the ISP router and also a wireless router using two interfaces.
ISP created two separate tunnel with failover to wireless from your end to the ISP.

b. How must have the ISP setup ?

ISP created the tunnel interface possibly to route the public IP they provided to you. They have created a static route for the public IP block towards your router.

c) ISP has provided the public ip address and how its routing to ISP.

The public subnet ISP provided to you is being routed via the tunnel interface. As there are multiple hops between your lan and ISP office, they have created the tunnel interface to make it reachable in a single hop. And at ISPs end, they have created a static route pointing towards you for the public IP subnet.

Techrunner

ASKER

Thanks

Is it kind of GRE tunneling ?

Thanks

Miftaul H

It is exactly a gre tunnel.

Techrunner

ASKER

Actually I need to understand from ISP point of view.

How they are playing with routing ?

let says they have another customer with setup ? How they do that ?

Please bear with me as I am trying to understand from ISP prespective.

Thanks

Techrunner

ASKER

I have slightly understood.

I can assume the ISP and Customer are connected with point to point ( or may be switch in the middle). They have GRE setup.

The customer is routing public IP to ISP and vice versa.

But just need to understand " How ISP would be routing those public to internet ?

Thanks

ASKER CERTIFIED SOLUTION

Miftaul H

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Techrunner

ASKER

Sorry for the delay. That was awesome explanation. Just few more questions

Lets I have internet connection from the ISP called as DIA. I have been given fiber connectivity to the customer router with a block 1.1.1.0/30. 1.1.1.1 will be ISP end and 1.1.1.2 will be customer end

And default route on customer router pointing to ISP router. What that type of connection could be ? Is is point to point connection ?

Thanks

SOLUTION

Miftaul H

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Techrunner

ASKER

Hi,
thanks

If possible can you provide me sanitized configuration of the case , Just for knowledge purposes or any example available on internet.

Thanks