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Two ISPs load sharing

bansal.ojasvi
Level 1
Level 1

Hello Experts,

I am trying to use two DSL ISPs to share my VOIP traffic of about 19 SIP phones using G711. I am thinking about using one 2811 router with three Fa interfaces. One interface will go to ISPA, second will go to ISPB and third will go to LAN.

As per my thought process, use two LANs and direct half the traffic through ISPA and half through ISPB. Do I have to use PBR for doing this. If yes, any suggestion or working configuration.

Thanks

OJ

27 Replies 27

Tshi M
Level 5
Level 5

I would use route-map for this setup. An ACL will go along with each subnet.

rgds,

Thanks... but I have a confusion.

How could I configure the default route? can I specify this?

ip route 0.0.0.0 0.0.0.0 xx.xx.xx.xxx

ip route 0.0.0.0 0.0.0.0 yy.yy.yy.yyy

OJ

Could anyone please help?

Are your ISPs providing IP space for you? Or are you advertising to them via BGP?

No BGP. just one static IP address per connection from the ISP. My ISP doesn't support for small customers.

I apologized for I misread your posting. But please take a look at this link as I hope it might be able to help or at least give you something to work with.

http://www.cisco.com/en/US/tech/tk648/tk361/technologies_configuration_example09186a00808d2b72.shtml

I was also thinking of using two VLANs so that the policy is based on different source addresses. If source is x route to ISPA and if source is y route to ISPB

I did as per the document but have an issue. I don't have a default router pointing to two different IP address.

I have attached the config from my test router.

Sh run

sh ip sla statistics

sh ip nat translation

sh ip route

sh ip int brief

sh flash

Any help on this would be very much appreciated.

Thanks

OJ

Hi Bansal,

It might not be related but your internal interface is showing up/down.

gentlemans,

I guess we are taking about load balancing and not redudancy.

Which means we need to send traffic on both the inteface connected to ISP. Sharing the load.

Redudant which means if one ISP fails traffic shift to othe one. If this is the case thats the above all comments are right.

This can be done using SLA also

You are absolutely right. The purpose here is load-balancing and not redundancy. As per the document on Cisco, I should have default route pointed towards two next hop IP addresses. In my case this is not happening.

Any ideas?

OJ

that is because I don't have it plugged into anything. This is a test scenario and I am wondering why I don't have two gateways for default router?

Any idea?

OJ

could someone please help me with this issue. does anyone have idea on how to do policy based routing with two Vlans. example:

if request comes from Vlan 1 use this gateway and if request comes from Vlan 2 use the other gateway.

Much appreciated.

OJ

Could you try this:

ip access-list standard vlan1

permit ip 10.1.1.0 0.0.0.255 any

ip access-list standard vlan2

permit ip 10.1.2.0 0.0.0.255 any

route-map vlan1 permit 10

match address vlan1

set ip nexthop ISP1

route-map vlan2 permit 10

match address vlan2

set ip nexthop ISP2

Or you could just use

ip route 0.0.0.0 0.0.0.0 ISP2 for the other traffic

Thanks for you help. I tried this. Please take a look at the attachment and guide me please. I really need this working.

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