FailOver ISR 4321

[farguisito]

Hi,

I have one ISR 4321 and I would like to use it to connect 2 ISPs. One Isp has PPPOE and Vlan Trunking connection and One ISP has Dynamic or Static ip public.

This router only has 2 Ports 10/100/1000 so I need one port more. 1 LAN and 2 WAN.

I want that when ISP1 will fail, The router reforward all traffic to ISP2.

I think about one scenary however I don´t know if this choice is a crazy combination.

Por example if I install one Layer 2 switch between de ISPs to the router ie 

ISP 1 (PPOE)          ISP2 (Static IP)

       \/                            \/

               Switch Layer 2

                        \/

                      (Ge0)

                 Router 4321

                      (Ge1)

                       \/

                      LAN

Through EEM script, when I won´t internet connection in ISP1, I can try to change all config of the port Ge0.

Do you think that is this possible?

Regards.

[paul driver]

Hello

Really no need for EEM as ip sla tracking with static routing be the easiest solution and it will provide you with what you have queried - However It all depends on what you would like to do with both circuits , just using one as a backup would be okay but your then you have link not doing anything which you’re paying for, You may be able to use both at the same time pushing various traffic between the two if desired.

Would you be using any dynamic routing or just static routing?

How many users is this for and what are the link BW values?

res
Paul

[farguisito]

Thanks Paul,

ISP2 is sattelite connection (10 Mbps), so this connections is slowest regarding the ISP1 (100 Mbps) so I want only ISP2 to backup connection.

Would you be using any dynamic routing or just static routing?

I must to config a PAT translate with port reforwing, and one static Routing because below the router I have one Switch L3 that its doing intervlan.

How many users is this for and what are the link BW values?

The users are 50.

If I want only failover, I think that the one way is EEM? isn´t it?

Regards.

[farguisito]

I am thinking that this solution can´t be good with EEM. If I lost the PPPOE conection of the interface G0/0/1, I must to change this interface to connect to the satellite modem (static ip).

However, If the PPPoE connection is ready, I can´t know when this is happening.

Do you know something to fix this problem?

Regards.

interface GigabitEthernet0/0/1
 no ip address
 ip nat outside
 shutdown
 negotiation auto
!
interface GigabitEthernet0/0/1.6
 encapsulation dot1Q 6
 ip nat outside
 pppoe enable group global
 pppoe-client dial-pool-number 1
 ip virtual-reassembly
!

!
interface Dialer1
 ip address negotiated
 ip nat outside
 encapsulation ppp
 ip tcp adjust-mss 1452
 dialer pool 1
 dialer-group 1
 ppp authentication chap pap callin
 ppp chap hostname xxxxx@xxxxxx
 ppp chap password 0 xxxxx
 ppp pap sent-username xxxxxx@xxxxxx password 0 xxxxx
 no cdp enable
 ip virtual-reassembly
!
ip nat inside source list 1 interface Dialer1 overload
ip forward-protocol nd
ip http server
ip http authentication local
ip http secure-server
ip tftp source-interface GigabitEthernet0

This is the PPPoE interface with Vlan Trunk (my fiber ISP required this config).

Regards.

[farguisito]

Could anybody help me please?

Regards.