Private Internet merge with Enterprise

[shahulhameed]

Good Day

We have two ISP's if primary goes down the secondary will work. Recently we moved to Office 365. We are facing frequently internet issue with these ISPs. We have near about 10 buildings each building has a access switch. The users are getting IP from DHCP server. My manager wants to install a wireless LTE router with high speed capabilities on each location and connect to the Access Switch.User should able to access Internet without changing IP or using our private IP. His aim is If our main ISPs not working the users at least have access Internet and can work Office 365 and Internet.

I have attached my Network lay out.

Please advise how it can be configured ?

I suggest to my manager don't implement this because it is not secured.But I don't know how to explain. Give me a valid point how can I explain to my manager? or is it ok?

Thanks and Regards,

Shahul Hameed.

[Vasilii Mikhailovskii]

Hello.

Not to change your public IP-address during ISP failover, you need to run PI addresses (and run BGP peering).

If you want to have additional LTE WAN link, put it the same place as others - in this case traffic will be running through firewall (secure).

>>His aim is If our main ISPs not working the users at least have access Internet and can work Office 365 and Internet.

I thought it's already fulfilled with secondary ISP, isn't it?

PS: when "We are facing frequently internet issue with these ISPs", you typically either open ticket to the ISPs or find another/more stable one. 

[shahulhameed]

Hello Vasilii

The design we need, if the link to CORE down the users need to access internet. I have little confusion about the configuration. Please sees the attachment and advise.

[Vasilii Mikhailovskii]

Hello.

If link to the core is down - you need another (backup)link to the core.

If your access switch may completely loose connectivity to the core, then it's not a CORE (in terms of design), but HQ.

Why do you expect link[s] to the CORE to go down?

[shahulhameed]

Hi Vasilii

Some times we have limit give suggestion to the manager.

How can we configure this scenario ?

Switch(config)# ip sla 11

Switch(config-ip-sla)# icmp-echo 78.22.33.3

Switch(config-ip-sla-echo)# frequency 10

Switch(config-ip-sla-echo)# exit ! 2x

Switch(config)# ip sla 22

Switch(config-ip-sla)# icmp-echo 125.36.56.45

Switch(config-ip-sla-echo)# frequency 10

Switch(config-ip-sla-echo)# exit ! 2x

Switch(config)# track 1 ip sla 11 reachability

Switch(config-track)# delay down 10 up 1

Switch(config-track)# exit

Switch(config)# track 2 ip sla 22 reachability

Switch(config-track)# delay down 10 up 1

Switch(config-track)# exit

Switch(config)# ip sla schedule 11 life forever start-time now

Switch(config)# ip sla schedule 22 life forever start-time now

Switch(config)# ip route 0.0.0.0 0.0.0.0 192.168.1.2 2 track 1

Switch(config)# ip route 0.0.0.0 0.0.0.0 192.168.1.3 3 track 2

Regards,