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BDunbar_8799's avatar
BDunbar_8799
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Feb 08, 2011

Routing traffic to remote sites using LTM

We have version 2 of an in-house application coming up. It has been decided that our F5 LTMs will be the front end to manage traffic.

 

 

There will be regional application servers, IIS. End users login to those. The question is the best way to tell a user at Site X to login to Site X's regional server.

 

 

The proposed method is for each client to use domain suffix search order to find the closest resource. Thus a client.juarez.company.com would find shop-floor.juarez.company.com. Neat and tidy.

 

 

I wondered if using an iRule would be a better solution. We know all users will be internal, we know our subnets [1] so if we assume ...

 

 

F5 LTM ver 9.4.6

 

Cluster

 

Located in the same subnet as global.company.com, at global headqarters.

 

 

subnets

 

 

Penang = 10.0.1

 

Xiamen = 10.0.2

 

Jaurez = 10.0.3

 

GHQ = 10.0.4

 

 

Pools

 

GSF_PD_PENANG

 

member: shop-floor.penang.company.com

 

 

GSF_PD_XIAMEN

 

member: shop-floor.xiamen.company.com

 

 

GSF_PD_JUAREZ

 

member: shop-floor.juarez.company.com

 

 

GSF_PD_GLOBAL

 

member: global.company.com

 

 

 

With an IRULE

 

 

pseudo-TCL

 

 

when CLIENT_ACCEPTED {

 

if {[IP::addr "[IP::client_addr]/24" equals "10.0.1/24"]} {

 

pool GSF_PD_PENANG

 

}

 

else if {[IP::addr "[IP::client_addr]/24" equals "10.0.2/24"]} {

 

pool GSF_PD_XIAMEN

 

}

 

elseif {[IP::addr "[IP::client_addr]/24" equals "10.0.3/24"]} {

 

pool GSF_PD_JUAREZ

 

}

 

else

 

{pool GSF_PD_GLOBAL}

 

}

 

 

 

1. Would this be viable?

 

 

2. The first question raised was 'would this mean traffic is routed from the the site, to the F5 LTM, then back to the site where the shop-floor.location.company.com server is?' Would it?

 

 

 

 

[1] Yes, I know these are not valid subnets. Example use only.

1 Reply

  • If all the connections are being proxied through the same LTM pair, it doesn't really matter if the servers are close to the clients. You'd just want to use the pool of servers closest to LTM. Now, if you're able to have the clients connect directly to the servers (or an LTM in the regional datacenter), then you'd want to use the servers closest to the client. If the clients can connect directly to the servers, you could use your logic or do a GeoIP lookup using the whereis command and redirect the clients to an IP address or hostname which points to the closest regional servers.

     

     

    Aaron