diff --git a/xCAT-test/unit/dhcp_infiniband_twin.t b/xCAT-test/unit/dhcp_infiniband_twin.t
new file mode 100644
index 000000000..81cf13336
--- /dev/null
+++ b/xCAT-test/unit/dhcp_infiniband_twin.t
@@ -0,0 +1,287 @@
+#!/usr/bin/env perl
+use strict;
+use warnings;
+
+use FindBin;
+use lib "$FindBin::Bin/../../xCAT-server/lib";
+use lib "$FindBin::Bin/../../xCAT-server/lib/perl";
+use lib "$FindBin::Bin/../../perl-xCAT";
+
+use Test::More;
+
+$ENV{XCATCFG} ||= 'SQLite:/tmp';
+
+my $source_dhcp_plugin = "$FindBin::Bin/../../xCAT-server/lib/xcat/plugins/dhcp.pm";
+if ( -f $source_dhcp_plugin ) {
+    require $source_dhcp_plugin;
+} else {
+    require xCAT_plugin::dhcp;
+}
+
+sub twin { return xCAT_plugin::dhcp::_infiniband_twin_mac( $_[0] ); }
+
+is(
+    xCAT_plugin::dhcp::normalize_mac('B8-3F-D2-4A-68-AA'),
+    'b8:3f:d2:4a:68:aa',
+    'the shared MAC normalizer canonicalizes case and separators',
+);
+is( twin('b8:3f:d2:4a:68:aa'), 'b8:3f:d2:03:00:4a:68:aa',
+    'the port GUID of the first adapter is derived from its mac' );
+is( twin('b8:3f:d2:4a:68:b2'), 'b8:3f:d2:03:00:4a:68:b2',
+    'the port GUID of the second adapter is derived from its mac' );
+is( twin('b8-3f-d2-4a-68-aa'), 'b8:3f:d2:03:00:4a:68:aa',
+    'a dash-separated mac produces a canonical InfiniBand identity' );
+is( length( twin('b8:3f:d2:4a:68:aa') ), 23,
+    'the derived address is eight bytes' );
+
+foreach my $other ( 'b8:3f:d2:03:00:4a:68:aa', '00:11:22:33:44', '', 'notamac' ) {
+    is( twin($other), undef, "'$other' gives no derived address" );
+}
+is( twin(undef), undef, 'no mac gives no derived address' );
+ok(
+    xCAT_plugin::dhcp::_infiniband_identity_present(
+        'b8:3f:d2:4a:68:aa!node01',
+        'b8:3f:d2:03:00:4a:68:aa!node01-ib',
+    ),
+    'an explicit InfiniBand identity is detected in a node mac list',
+);
+ok(
+    xCAT_plugin::dhcp::_infiniband_identity_present(
+        'b83fd203004a68aa!node01-ib',
+    ),
+    'a colonless InfiniBand identity is detected in a node mac list',
+);
+ok(
+    !xCAT_plugin::dhcp::_infiniband_identity_present(
+        'b8:3f:d2:4a:68:aa!node01',
+    ),
+    'an Ethernet-only mac list needs the derived identity',
+);
+
+is(
+    xCAT_plugin::dhcp::_node_host_statements('node01', ''),
+    'ddns-hostname \"node01\"; send host-name \"node01\";',
+    'the default host statements identify the node',
+);
+is(
+    xCAT_plugin::dhcp::_node_host_statements(
+        'node01', 'filename = \"bootfile\";'
+    ),
+    'ddns-hostname \"node01\"; send host-name \"node01\";filename = \"bootfile\";',
+    'node identity is prepended to existing host statements',
+);
+
+my $create_commands = <<'OMAPI';
+new host
+set name = "node01-xcat-ib"
+open
+remove
+close
+new host
+set name = "node01-xcat-ib"
+set hardware-address = b8:3f:d2:03:00:4a:68:aa
+set dhcp-client-identifier = b8:3f:d2:03:00:4a:68:aa
+set hardware-type = 32
+set ip-address = 192.0.2.10
+set statements = "ddns-hostname \"node01\"; send host-name \"node01\";"
+create
+close
+OMAPI
+
+is(
+    xCAT_plugin::dhcp::_infiniband_twin_create_commands(
+        'node01', 'b8:3f:d2:4a:68:aa', 1, 'ib0', '192.0.2.10',
+        'ddns-hostname \"node01\"; send host-name \"node01\";', 1, 0
+    ),
+    $create_commands,
+    'an Ethernet identity on an IPoIB network creates the InfiniBand twin',
+);
+
+is(
+    xCAT_plugin::dhcp::_infiniband_twin_create_commands(
+        'node01', 'b8:3f:d2:4a:68:aa', 1, 'ib0', 'DENIED', '', 1, 0
+    ),
+    join( '', ( split( /^/m, $create_commands ) )[ 0 .. 9 ] )
+      . "set statements = \"deny booting;\"\ncreate\nclose\n",
+    'a denied Ethernet identity creates a denied InfiniBand twin',
+);
+
+is(
+    xCAT_plugin::dhcp::_infiniband_twin_create_commands(
+        'node01', 'b8:3f:d2:4a:68:aa', 32, 'ib0', '192.0.2.10', '', 1, 1
+    ),
+    undef,
+    'an existing InfiniBand identity does not create another twin',
+);
+is(
+    xCAT_plugin::dhcp::_infiniband_twin_create_commands(
+        'node01', 'b8:3f:d2:4a:68:aa', 1, 'eth0', '192.0.2.10', '', 1, 0
+    ),
+    undef,
+    'an Ethernet network does not create an InfiniBand twin',
+);
+
+my $create_without_cleanup = <<'OMAPI';
+new host
+set name = "node01-xcat-ib"
+set hardware-address = b8:3f:d2:03:00:4a:68:aa
+set dhcp-client-identifier = b8:3f:d2:03:00:4a:68:aa
+set hardware-type = 32
+set ip-address = 192.0.2.10
+set statements = "ddns-hostname \"node01\"; send host-name \"node01\";"
+create
+close
+OMAPI
+is(
+    xCAT_plugin::dhcp::_infiniband_twin_create_commands(
+        'node01', 'b8:3f:d2:4a:68:aa', 1, 'ib0', '192.0.2.10',
+        'ddns-hostname \"node01\"; send host-name \"node01\";', 0, 0
+    ),
+    $create_without_cleanup,
+    'the Ubuntu-limited OMAPI path creates the twin without a failed-open cleanup',
+);
+my $create_without_address = $create_without_cleanup;
+$create_without_address =~ s/^set ip-address = .*\n//m;
+is(
+    xCAT_plugin::dhcp::_infiniband_twin_create_commands(
+        'node01', 'b8:3f:d2:4a:68:aa', 1, 'ib0', undef,
+        'ddns-hostname \"node01\"; send host-name \"node01\";', 0, 0
+    ),
+    $create_without_address,
+    'an unresolved IP omits only the twin address',
+);
+is(
+    xCAT_plugin::dhcp::_infiniband_twin_create_commands(
+        'node01', 'b8:3f:d2:4a:68:aa', 1, 'ib0', '192.0.2.10', '', 1, 1
+    ),
+    undef,
+    'an explicit InfiniBand identity suppresses the derived twin',
+);
+
+is_deeply(
+    [ xCAT_plugin::dhcp::_infiniband_twin_static_lines(
+        'node01', 'b8:3f:d2:4a:68:aa', 1, 'ib0', '192.0.2.10',
+        'option host-name "node01";', 0
+    ) ],
+    [
+        "host node01-xcat-ib {\n",
+        "    hardware infiniband b8:3f:d2:03:00:4a:68:aa;\n",
+        "    fixed-address 192.0.2.10;\n",
+        "    option host-name \"node01\";\n",
+        "}\n",
+    ],
+    'the static-host fallback declares the derived InfiniBand identity',
+);
+
+my $delete_name_commands = <<'OMAPI';
+new host
+set name = "node01-xcat-ib"
+open
+remove
+close
+OMAPI
+my $delete_address_commands = <<'OMAPI';
+new host
+set hardware-address = b8:3f:d2:03:00:4a:68:aa
+set hardware-type = 32
+open
+remove
+close
+OMAPI
+
+is(
+    xCAT_plugin::dhcp::_hardware_address_delete_commands(
+        'b8:3f:d2:4a:68:aa', 1
+    ),
+    "new host\nset hardware-address = b8:3f:d2:4a:68:aa\nopen\nremove\nclose\n",
+    'Ethernet cleanup keeps the legacy hardware-address lookup',
+);
+is(
+    xCAT_plugin::dhcp::_hardware_address_delete_commands(
+        'b8:3f:d2:03:00:4a:68:aa', 32
+    ),
+    $delete_address_commands,
+    'InfiniBand cleanup includes its OMAPI hardware type',
+);
+
+my @delete_commands = xCAT_plugin::dhcp::_infiniband_twin_delete_commands(
+    'node01', 'b8:3f:d2:4a:68:aa', 1, 'ib0', 1, 0
+);
+is_deeply(
+    \@delete_commands,
+    [ $delete_name_commands, $delete_address_commands ],
+    'removing a node produces separate name and address cleanup commands',
+);
+my @moved_network_delete_commands =
+  xCAT_plugin::dhcp::_infiniband_twin_delete_commands(
+    'node01', 'b8-3f-d2-4a-68-aa', 1, 'eth0', 1, 1
+  );
+is_deeply(
+    \@moved_network_delete_commands,
+    [ $delete_name_commands, $delete_address_commands ],
+    'removing a node cleans up its old twin after network metadata changes',
+);
+my @limited_delete_commands =
+  xCAT_plugin::dhcp::_infiniband_twin_delete_commands(
+    'node01', 'b8:3f:d2:4a:68:aa', 1, 'ib0', 0, 0
+  );
+is_deeply(
+    \@limited_delete_commands,
+    [ $delete_name_commands, undef ],
+    'the Ubuntu-limited OMAPI path still removes the twin by name',
+);
+my @limited_ethernet_delete_commands =
+  xCAT_plugin::dhcp::_infiniband_twin_delete_commands(
+    'node01', 'b8:3f:d2:4a:68:aa', 1, 'eth0', 0, 0
+  );
+is_deeply(
+    \@limited_ethernet_delete_commands,
+    [],
+    'the Ubuntu-limited OMAPI path avoids a failed-open cleanup on Ethernet',
+);
+
+my @moved_network_update_commands =
+  xCAT_plugin::dhcp::_infiniband_twin_update_commands(
+    'node01', 'b8:3f:d2:4a:68:aa', 1, 'eth0', '192.0.2.10',
+    'ddns-hostname \"node01\"; send host-name \"node01\";', 1, 0
+  );
+is_deeply(
+    \@moved_network_update_commands,
+    [ $delete_name_commands, $delete_address_commands, undef ],
+    're-registering a node on Ethernet removes its former InfiniBand twin',
+);
+
+my @infiniband_update_commands =
+  xCAT_plugin::dhcp::_infiniband_twin_update_commands(
+    'node01', 'b8:3f:d2:4a:68:aa', 1, 'ib0', '192.0.2.10',
+    'ddns-hostname \"node01\"; send host-name \"node01\";', 1, 0
+  );
+is_deeply(
+    \@infiniband_update_commands,
+    [ $delete_name_commands, $delete_address_commands, $create_without_cleanup ],
+    're-registering an IPoIB node replaces its generated twin',
+);
+
+my @limited_update_commands =
+  xCAT_plugin::dhcp::_infiniband_twin_update_commands(
+    'node01', 'b8:3f:d2:4a:68:aa', 1, 'ib0', '192.0.2.10',
+    'ddns-hostname \"node01\"; send host-name \"node01\";', 0, 0
+  );
+is_deeply(
+    \@limited_update_commands,
+    [ undef, undef, $create_without_cleanup ],
+    'the limited OMAPI path does not attempt a failed-open cleanup',
+);
+
+my @explicit_identity_update_commands =
+  xCAT_plugin::dhcp::_infiniband_twin_update_commands(
+    'node01', 'b8:3f:d2:4a:68:aa', 1, 'ib0', '192.0.2.10',
+    'ddns-hostname \"node01\"; send host-name \"node01\";', 1, 1
+  );
+is_deeply(
+    \@explicit_identity_update_commands,
+    [ $delete_name_commands, undef, undef ],
+    'updating an explicit InfiniBand identity does not remove it by address',
+);
+
+done_testing();