Configuring Multiple Internet paths

[bbeachy2001]

I am in the process of setting up a backup internet circuit, and am trying to figure out the best way to configure our core switch.

We have a 3550, and it has the default route set to the address of the PIX handling the primary internet circuit. I now have the backup circuit also connected to the switch (via a cable modem > PIX > 2801 router)

We want to limit the use of the backup circuit to only a select subnet by default, and then to a larger subnet (but not the entire network) should the primary internet circuit go down.

My first thought was to set the secondary circuit up also as a default route, but use an access-list to deny all traffic to it (on the port it is connected to) except for the specific subnet that I want to use this circuit all the time. I would then, I assume, have to apply another access list to the primary internet circuit port denying access to that specific subnet, and allowing all others.

Is there a simpler way to accomplish this?

Thanks

 

[Minue]

You can also consider using the "ip next-hop" for the choosen subnets.
Regards

 

[zinkann]

Policy Based Routing

http://www.cisco.com/en/US/tech/tk364/technologies_configuration_example09186a00802135d3.shtml

CCNA, Network+

 

[bbeachy2001]

I think Policy Based Routing is just what I was looking for. However, I am stuck. I have followed all the steps, and have my route map set up, but when I go to configure the interface with the ip policy route-map, it won't let me. It doesn't look like there I can do that. If I do a ip ?, it doesn't even show ip policy as being an option.

I am running 12.1(12c) on this switch. Do I need to upgrade to 12.2 before this will work?

Thanks,
Branden

 

[Minue]

Without doubt it's an IOS issue!You may need to upgrade to an enterprise version.
Regards

 

[Deepseadata]

Hey there,

I am researching policy-based routing at the moment.

I have a 2801 and have planned to use both Fast Eth int's for internet.

I just checked my IOS and the commands are there!

Now I need to start learning how I'll make it work for me.

I have to Satellites as my internet links. I have "important users" in their own vlan. Which scenario is better for speed and reliability?

If I have both internet feeds running in parallel, can bind them to look like one and then use PBR as a QOS mechanism to give priority to certain vlans?

Thanks y'all.

 

[jneiberger]

If the devices that require Internet access are connected to the switch, then you'd need PBR on the switch. Can a 3550 do L3? I haven't really used them much, so I'm not really aware of their capabilities.

You basically want to have two different destinations depending on the source address, which requires PBR. But since PBR is a layer three feature, it has to be applied on a routed interface, not a switched interface.

 

[Minue]

Hello Jneiberger
With the right IOS,the 3550 will even do BGP.
Deepseadata!When you need help please open a new thread.
Regards

 

[Deepseadata]

OK Minue,

Sorry everyone.