We use a multi-tiered server infrastructure like...
[fe-1] [fe-2] [fe-3] [fe-4] ... [fe-n]
[mta-in-1] [mta-in-2] ... [mta-in-n]
[mta-out-1] [mta-out-2] ... [mta-out-n]
[[be-1-a][be-1-b]] [[be-2-a][be-2-b]] ... [be-m-a][be-m-b]]
[ldap-master-1] <-MMR-> [ldap-master-2]
So, there are "n" front-end hosts behind a firewall and load balancer, then another firewall between the frontends and the "m" clusters of back-ends, and LDAP servers (and other various "data tier" machines). When a user logs in, they authenticate via LDAP and the front-end "server" proxies them to the proper "backend" host (be-2 for example) .. The system "be-2" is normally a cluster (a and b nodes), but for now, we are not clustering the backend to keep things simple, also we don't have (the need for) web based power switches that RHCS seems to require?
I cannot figure out the proper set of options to configure the front-end servers. Creating an MTA-only is fairly easy, but I want an MTA, webmail interface (to include mobile sync capability), and imap proxy on one host, but not a store.
I have found that perdition doesn't seem to install unless you choose a store, but now I am in the configuration and its having me create all this unnecessary stuff (domains/users/etc).. How should I configure this screen for a simple front-end proxy? I have already pointed it at our LDAP master (does openldap not support multi-master?)..
I tried going through by just enabling the proxy, but lots of stuff was failing cause it wanted to contact mysql (?) and was also trying to contact the admin port on the backend host. I also note that the backend is attempting to contact the front-end admin port (and maybe others?)..
So, questions are...
1. is there a way to install a front-end mail server that is similar in function to the mta-only host, but also has perdition and whatever is necessary to make webmail work (assuming it can run on the front end and connect to the backend via (???))
2. what port opening are necessary in the firewall besides the basic 25/80/143/443/993 ?
Thanks in advance,