dhcpd conf syntax error - upgrading from RHEL6 to RHEL7 - dhcp 4.2

Question

can someone help me figure out what the syntax issue is here. This block works in RHEL6 dhcpd.conf (dhcp-4.1.1-63.P1.el6_10.x86_64) file but is throwing an error when I am upgrading to RHEL7 (dhcp-4.2.5-82.el7.x86_64)

 30 on commit {
 31         if (not static and ((config-option server.ddns-updates = null) or (config-option server.ddns-updates != 0))) {
 32                 if exists oe-key {
 33                         set ddns-rev-name = concat (binary-to-ascii (10, 8, ".", reverse (1, leased-address)), ".", pick (config-option server.ddns-rev-domainname    , "in-addr.arpa."));
 34                         set full-oe-key = option oe-key;
 35                         switch (ns-update (delete (IN, 25, ddns-rev-name, null), add (IN, 25, ddns-rev-name, full-oe-key, lease-time / 2)))
 36                         {
 37                           default:
 38                           unset ddns-rev-name;
 39                           break;
 40                           case NOERROR:
 41                           on release or expiry {
 42                             switch (ns-update (delete (IN, 25, ddns-rev-name, null))) {
 43                               case NOERROR:
 44                               unset ddns-rev-name;
 45                               break;
 46                             }
 47                           }
 48                         }
 49                 }
 50         }
 51 }

error

/etc/dhcp/dhcpd.conf line 35: expecting expression.
                        switch (ns-update (delete 

it appears that there are some changes to the parameters RELNOTES

775 - Replaced ifconfig parameters "add" and "delete" with "alias" and "-alias" 
776 for IPv6 mode in the client scripts, netbsd and openbsd. This was 
777 preventing IPv6 addresses from being added or removed from interfaces. 778 Thanks to Tim Dean for reporting this issue. 779 [ISC-bugs #31573] 

Does anyone have more insight into how to construct these confs now to include add,delete and switch cases?

Answer 1

等待大神答复