Cisco Support Community
cancel
Showing results for 
Search instead for 
Did you mean: 
Announcements

Welcome to Cisco Support Community. We would love to have your feedback.

For an introduction to the new site, click here. And see here for current known issues.

New Member

WAN Link fail over

Hi, my name is John. We have 1 uplink connected to a Cisco 1900 series router and another 1 uplink connected to a Cisco 3000 series router. Two uplink from 2 different ISP. My question is how can i configure the routers so that when 1 uplink failed, the other 1 uplink will take over without any service disruption?

7 REPLIES
Cisco Employee

Hi John As per your query I

Hi John
 
As per your query I have created a diagram that may be your setup and to achive the redudancy from device and link prospective you can use multiple solutions;
 
 
Diagram:
 
     ---- RTR 1---------- ISP1
   /
LAN        |
   \
    ------RTR 2 --------- ISP2
 
 
- to achive the device redundnacy and redundancy from LAN prospective use HSRP with link tracking so that in case any link fails or router fails the other device will pass the traffic
- From link redundnacy prospective you can use multiple solution depending on the kind of link that you taken from the provides. 
- If the links are L1/L2 and you have taken these link for communicating to other sites than you can use IGP routing protocol (ospf).
Example:
 
RTR1: 
   router ospf 1
   network <lan network> <wild mask> area 0
   network <wan network> <wild mask> area 0
   network <RTR-to-rtr>  <wild mask> area 0  > u can eliminate this link if you want to use via lan sw
  
- If you have taken these link for internet access than you can use static/default route with admin distance. make sure RTR1 should be hsrp active and only in case of isp1 failure RTR2 take over.
 
    Example 
 RTR1:
  ip route 0.0.0.0 0.0.0.0 <ISP1 ip>
 
RTR2: 
  ip route 0.0.0.0 0.0.0.0 <ISP2 ip> 10
 
Solution may change as per the type of link or requirement.
 
If you have any query please feel free to contact.
 
Thanks & Regards
Sandeep
New Member

Hi Sandeep, Thanks for your

Hi Sandeep,

 

Thanks for your suggestion.

Can you advise how can i configure HSRP and link redundancy?

We does not need to connect to other sites but we need to connect to internet resources.

Do you have any use cases or example that i can reference?

Cisco Employee

Hi,please find below the hsrp

Hi,

please find below the hsrp configuration:

RTR1:

intrface <interface-name>
standby 1 ip <hsrp-virtual-ip>
standby 1 preempt
standby 1 priority 110
standby 1 track <wan-interface> 20


RTR2:

intrface <interface-name>
standby 1 ip <hsrp-virtual-ip>
standby 1 track <wan-interface> 20

also refer this link for more details:

 

http://www.cisco.com/c/en/us/support/docs/ip/hot-standby-router-protocol-hsrp/13780-6.html

Thanks & Regards

Sandeep

New Member

Hi Sandeep,In the case that i

Hi Sandeep,

In the case that i put aside the fail-over configuration first.

And i would like to test each uplink respectively to see if the uplinks works.

1 of the uplink have static IP and the other 1 is based on DHCP.

In this case, for the uplink with static IP, should i configure as 

  ip route 0.0.0.0 0.0.0.0 <ISP ip>
 

And for the uplink with dynamic IP address, should i configure the static route reference to my router exit interface?

  ip route 0.0.0.0 0.0.0.0 <router exit interface>

Thanks in advanced.

New Member

Hi Sandeep,Thanks for your

Hi Sandeep,

Thanks for your suggestion.

I will try this out but not this week and let you know if it works or not.

 

New Member

Hi Sandeep,Just want to say

Hi Sandeep,

Just want to say that my new network diagram should be like this 

Diagram:
 
     ---- RTR 1---------- -----                                                                  -----------------ISP1
   /                                      \                                                              /
LAN        |                                Switches in redundancy  --------Firewall
   \                                       /                                                             \
     --------RTR 2 ------------                                                                  -----------------ISP2
Super Bronze

DisclaimerThe Author of this

Disclaimer

The Author of this posting offers the information contained within this posting without consideration and with the reader's understanding that there's no implied or expressed suitability or fitness for any purpose. Information provided is for informational purposes only and should not be construed as rendering professional advice of any kind. Usage of this posting's information is solely at reader's own risk.

Liability Disclaimer

In no event shall Author be liable for any damages whatsoever (including, without limitation, damages for loss of use, data or profit) arising out of the use or inability to use the posting's information even if Author has been advised of the possibility of such damage.

Posting

Basically, each router would, if its own link fails, redirect to the other router.  Can be difficult to accomplish without any service disruption, but not too difficult to accomplish with minimum (milliseconds) service interruption.

178
Views
0
Helpful
7
Replies
CreatePlease login to create content