failover/backup question

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Mar 3rd, 2004
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Situation: I am currently running EIGRP between 2 routers in 2 different locations connected by 2 serial point to point ckts. EIGRP is performing the routing, load balancing, and failover. However due to a reroute of one of my circuits it has added a longer delay which could potentially cause a problem to my VOIP traffic. So I want to route my VOIP traffic through one ckt and my data through the other. Since the VOIP traffic is on its own network the routing is simple. I can either route by static routes or route maps. The issue for me is when I want to use the other circuit for failover. If one circuit goes down I need to be able to route all traffic over remaining ckt. How do I do this?


Networks:

Router A

F0/0 192.168.1.1/24 VOIP

F0/1 192.168.2.1/24 Data

S0/0 192.168.3.1/30 Pt to Pt

S0/1 192.168.3.5/30 pt to pt


Router B

F0/0 192.168.4.1/24 VOIP

F0/1 192.168.5.1/24 Data

S0/0 192.168.3.2/30 Pt to Pt

S0/1 192.168.3.6/30 pt to pt





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dbellazetin Wed, 03/03/2004 - 08:28
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Greg,


If you plan on doing this with static routes just point a static route to the next hop of the circuit you would like to be the primary for both your data and voice, and then configure a floating static routes so if the primary circuit fails they will use the alternate interface.


Example A -


ip route 192.168.4.1 255.255.255.0 serial 0

ip route 192.168.4.1 255.255.255.0 serial 1 25

ip route 192.168.5.1 255.255.255.0 serial 1

ip route 192.168.5.1 255.255.255.0 serial 0 25


Example B -


ip route 192.168.1.1 255.255.255.0 serial 0

ip route 192.168.1.1 255.255.255.0 serial 1 25

ip route 192.168.2.1 255.255.255.0 serial 1

ip route 192.168.2.1 255.255.255.0 serial 0 25


The 25 at the end of the router indicates to the router that it can only use this route if no other route has a better admin distance.


With this configuration the router will fail over to the floating static route if the line protocol on the primary interface goes down causing the primary route to be removed from the table.


Daniel

greg.moore1 Wed, 03/03/2004 - 08:56
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Thanks. I new about different weights but was not sure how well they worked with static routes.

vcjones Wed, 03/03/2004 - 14:40
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A quick word of caution: This approach with static routes will only be robust to the extent that link failures are reliably detected at the link level. This is automatic with "real" point-to-point links, as long as you do not disable keepalives, but requires extra work if your links are frame relay.


Good luck and have fun!


Vincent C Jones

greg.moore1 Thu, 03/04/2004 - 04:51
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True. What I was thinking about was running EIGRP just for my VOIP traffic because this is the most important traffic for our business (call center). This way I can just tune EIGRP to have a primary and secondary route. I will then use the floating static route to send the data over the "secondary line" for the data traffic. The failover for the data line would be with a floating static pointing to the "primary" line, understanding that the failover will only work if the link is detected down.


Thanks,


Greg

gkiboneka Wed, 03/03/2004 - 19:42
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Greg i am trying to accomplish the same thing for , can you send me sample config you are using for failover

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