Multi homing howto

[agentflicker]

Hello all,

I need a bit of help to start me on my way with setting up a basic multi homed setup. I'v never attempted anything like this before.

We currently have our firewall connected to a router that is connected to our ISP. We now want to use another ISP for redundancy. I'm sure a million sites must have this sort of setup and there are many ways to go about it. So if anyone can give me any suggested reading, usefull links, step by step guides, etc to start planning this I would be greatfull.

Cheers Simon.

 

[Saeed42]

This Cisco page will show you how to do this for BGP using HSRP, if you are using any other protocol it should be very similar

http://www.cisco.com/warp/public/459/hsrp_bgp.html

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Don't be content with being average. Average is as close to the bottom as it is to the top
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[saleen351]

hopefully you are going to add another router. r u also going to load balance also? or you will just use isp1 and then wait till it goes down and then start using isp2? cisco recommends using BGP if you connect to 2 different isps. are you currently using a static route to your only isp right now or will you be using ospf to update the isp1 and isp2 routers so they will send your networks ip to the rest of the internet core. r u looking for redundacy and symmetry. theirs alot more involve in here. how will the 2nd router know when to start routing traffic when the other router goes down. just remember, right now, you only have 1 route out of your network and people will know if it goes down. alot of planning is much better then telling each user that they cannot why they cannot get to their favorite website. will be happy to answer any particular question you may have.

 

[wybnormal]

HSRP is ok except the router that is in standby is just that.. standby.. he does nothing except wait. But, if you set up HSRP with each router in a group and then the GROUP provides the standby, you can still use the *backup* router for other things.

Regarding HSRP and BGP.. BGP is not required for HSRP. HSRP is a protocol all to itself and does not need a routing protocol like BGP to function. It sends *keep alives* to other HSRP routers via multicast packets.

Also, consider policy routing. You can config the primary router to examine the incoming packets and if the primary link is down, then ship them back on to the lan and over to the back up router/link combo. It's pretty easy to config. YOu can tune it via access lists to only move over web traffic or all traffic..

http://www.cisco.com/warp/public/473/62.shtml#basicoperation

MikeS
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"The trouble with giving up civil rights is that you never get them back"

 

[BuckWeet]

Keep in mind though, to run BGP you need your own IP's, then you'll have to get your own autonomous system number to be able to pass BGP routes across the net..


BuckWeet