I would like to have two network connections on my hosts, one for user facing access (http, NFS, SMB etc) and a back end for administration. When I add a 2nd NIC to my system I get terrible delays logging into my hosts (presumably they are trying to contact the LDAP server over both NICs). Is there a way I can let the system know to only use a specific NIC per service (or multiple as needed).

For instance I'd like to have http <-> SQL traffic only on the back end network. The same for backups, snmp etc. Authentication needs to be on the front end since my users will need to log in. How to I tell services which interface to use?