At some places you can use the * wildcard as a service description (which requires use_regexp_matching=0), but sometimes it does not seem to work:

Error: Could not expand services specified

Therefore, I simply wanted to group all services in one servicegroup. That’s quite easy if you use a generic service template as a basis for all services. First, create a servicegroup “allservices”:

define servicegroup {
        servicegroup_name               allservices
        alias                           All Services
}

Then edit your generic service template (see servicegroups line):

# generic service template definition
define service{
        name                            generic-service ; The 'name' of this service template
        active_checks_enabled           1       ; Active service checks are enabled
        passive_checks_enabled          1       ; Passive service checks are enabled/accepted
        parallelize_check               1       ; Active service checks should be parallelized (disabling this can lead to major performance probl$
        obsess_over_service             1       ; We should obsess over this service (if necessary)
        check_freshness                 0       ; Default is to NOT check service 'freshness'
        notifications_enabled           1       ; Service notifications are enabled
        event_handler_enabled           1       ; Service event handler is enabled
        flap_detection_enabled          1       ; Flap detection is enabled
        failure_prediction_enabled      1       ; Failure prediction is enabled
        process_perf_data               1       ; Process performance data
        retain_status_information       1       ; Retain status information across program restarts
        retain_nonstatus_information    1       ; Retain non-status information across program restarts
        notification_interval           0               ; Only send notifications on status change by default.
        is_volatile                     0
        check_period                    24x7
        normal_check_interval           5
        retry_check_interval            1
        max_check_attempts              4
        notification_period             24x7
        notification_options            w,u,c,r
        contact_groups                  admins
        servicegroups                   allservices ; ADD THIS TO ADD ALL SERVICES INTO THE allservices GROUP
        register                        0       ; DONT REGISTER THIS DEFINITION - ITS NOT A REAL SERVICE, JUST A TEMPLATE!
        }

This assumes all your services use this template like this (see use line):

define service {
        hostgroup_name                  ssh-servers
        service_description             SSH
        check_command                   check_ssh
        use                             generic-service  ; USE THE TEMPLATE ABOVE
        notification_interval           0 ; set > 0 if you want to be renotified
}

Now you can easily use this servicegroup for example in serviceescalations (see servicegroup_name line):

 define serviceescalation{
        hostgroup_name          intranet-servers
        servicegroup_name       allservices
        first_notification      1
        last_notification       0
        notification_interval   1440
        contact_groups          intranet-admins
        }

Hope this helps somebody. I guess it works the same way in Nagios.