diff --git a/perl-xCAT/xCAT/DHCP/Backend.pm b/perl-xCAT/xCAT/DHCP/Backend.pm
index 1a753b981..0132f8a97 100644
--- a/perl-xCAT/xCAT/DHCP/Backend.pm
+++ b/perl-xCAT/xCAT/DHCP/Backend.pm
@@ -59,8 +59,9 @@ sub default_backend {
 
     my $os_name = exists $args{os_name} ? $args{os_name} : $class->_osver('os');
     my $version = exists $args{version} ? $args{version} : $class->_osver('version');
-    if ( defined($os_name) && $os_name =~ /^ubuntu$/i && _version_at_least( $version, '22.04' ) ) {
-        return 'kea';
+    if ( defined($os_name) && $os_name =~ /^ubuntu$/i && defined($version) && $version =~ /^\d+\.\d+(?:\.\d+)*$/ ) {
+        require xCAT::Utils;
+        return 'kea' if xCAT::Utils->version_cmp( $version, '22.04' ) >= 0;
     }
 
     return 'isc';
@@ -153,23 +154,4 @@ sub _command_exists {
     return 0;
 }
 
-sub _version_at_least {
-    my ( $version, $minimum ) = @_;
-
-    return 0 unless defined($version) && $version =~ /^\d+\.\d+(?:\.\d+)*$/;
-
-    my @version_parts = split /\./, $version;
-    my @minimum_parts = split /\./, $minimum;
-    my $max = @version_parts > @minimum_parts ? @version_parts : @minimum_parts;
-
-    for my $idx ( 0 .. $max - 1 ) {
-        my $left  = $version_parts[$idx] || 0;
-        my $right = $minimum_parts[$idx] || 0;
-        return 1 if $left > $right;
-        return 0 if $left < $right;
-    }
-
-    return 1;
-}
-
 1;
diff --git a/perl-xCAT/xCAT/DHCP/Backend/Kea.pm b/perl-xCAT/xCAT/DHCP/Backend/Kea.pm
index e83c55673..c4c1a27e0 100644
--- a/perl-xCAT/xCAT/DHCP/Backend/Kea.pm
+++ b/perl-xCAT/xCAT/DHCP/Backend/Kea.pm
@@ -899,7 +899,10 @@ sub _use_modern_additional_class_syntax {
     return 0 if $self->{additional_class_syntax} && $self->{additional_class_syntax} eq 'legacy';
 
     my $version = $self->kea_version();
-    return _version_at_least( $version, '2.7.4' );
+    return 0 unless defined($version) && $version =~ /\A\d+(?:\.\d+)*(?:-[A-Za-z0-9]+)?\z/;
+
+    require xCAT::Utils;
+    return xCAT::Utils->version_cmp( $version, '2.7.4' ) >= 0 ? 1 : 0;
 }
 
 sub kea_version {
@@ -934,25 +937,6 @@ sub _first_defined {
     return;
 }
 
-sub _version_at_least {
-    my ( $version, $minimum ) = @_;
-
-    return 0 unless defined($version) && $version =~ /^\d+(?:\.\d+)*/;
-
-    my @version_parts = split /\./, $version;
-    my @minimum_parts = split /\./, $minimum;
-    my $max = @version_parts > @minimum_parts ? @version_parts : @minimum_parts;
-
-    for my $idx ( 0 .. $max - 1 ) {
-        my $left  = $version_parts[$idx]  || 0;
-        my $right = $minimum_parts[$idx] || 0;
-        return 1 if $left > $right;
-        return 0 if $left < $right;
-    }
-
-    return 1;
-}
-
 sub _integer {
     my ($value) = @_;