diff --git a/ansible/generate_topo.py b/ansible/generate_topo.py
index 9da8a957fd..a574b137a2 100755
--- a/ansible/generate_topo.py
+++ b/ansible/generate_topo.py
@@ -346,6 +346,7 @@ def _find_lag_port(port_id: int) -> bool:
             end_vlan_range = link_id_start + len(lag_port) * num_breakout
 
             vm_role_cfg["asn"] += vm_role_cfg.get("asn_increment", 1)
+            vm_role_cfg["asn_v6"] += vm_role_cfg.get("asn_increment", 1)
             vm = VM(range(link_id_start, end_vlan_range), len(vm_list), per_role_vm_count[vm_role_cfg["role"]], tornum,
                     dut_role_cfg["asn"], dut_role_cfg["asn_v6"], vm_role_cfg, link_id_start,
                     num_lags=len(lag_port) * num_breakout)
@@ -372,14 +373,19 @@ def _find_lag_port(port_id: int) -> bool:
 
             # Create the VM or host interface based on the configuration
             if vm_role_cfg is not None:
-                per_role_vm_count[vm_role_cfg["role"]] += 1
+                if 'lt2' not in role:    # For non LT2 topo , the VM id is per-link basis.
+                    per_role_vm_count[vm_role_cfg["role"]] += 1
 
                 if (link_id - link_id_start) % link_step == 0 and panel_port_id not in skip_ports:
                     # Skip breakout if defined
                     if (panel_port_id, link_id - link_id_start) in skip_ports:
                         continue
 
+                    if 'lt2' in role:  # for LT2 topo, the VM id is continuous regardless of the link.
+                        per_role_vm_count[vm_role_cfg["role"]] += 1
+
                     vm_role_cfg["asn"] += vm_role_cfg.get("asn_increment", 1)
+                    vm_role_cfg["asn_v6"] += vm_role_cfg.get("asn_increment", 1)
                     vm = VM(link_id, len(vm_list), per_role_vm_count[vm_role_cfg["role"]], tornum,
                             dut_role_cfg["asn"], dut_role_cfg["asn_v6"], vm_role_cfg, link_id,
                             num_lags=vm_role_cfg.get('num_lags', 0))
diff --git a/ansible/vars/topo_t1-isolated-v6-d56u1-lag.yml b/ansible/vars/topo_t1-isolated-v6-d56u1-lag.yml
index 6ba4a3bf71..4aea55e109 100644
--- a/ansible/vars/topo_t1-isolated-v6-d56u1-lag.yml
+++ b/ansible/vars/topo_t1-isolated-v6-d56u1-lag.yml
@@ -256,7 +256,7 @@ configuration:
     tornum: 1
     bgp:
       router-id: 100.1.0.1
-      asn: 4200000000
+      asn: 4200000001
       peers:
         4200100000:
           - fc00::1
@@ -274,7 +274,7 @@ configuration:
     tornum: 2
     bgp:
       router-id: 100.1.0.9
-      asn: 4200000000
+      asn: 4200000002
       peers:
         4200100000:
           - fc00::21
@@ -292,7 +292,7 @@ configuration:
     tornum: 3
     bgp:
       router-id: 100.1.0.17
-      asn: 4200000000
+      asn: 4200000003
       peers:
         4200100000:
           - fc00::41
@@ -310,7 +310,7 @@ configuration:
     tornum: 4
     bgp:
       router-id: 100.1.0.25
-      asn: 4200000000
+      asn: 4200000004
       peers:
         4200100000:
           - fc00::61
@@ -328,7 +328,7 @@ configuration:
     tornum: 5
     bgp:
       router-id: 100.1.0.33
-      asn: 4200000000
+      asn: 4200000005
       peers:
         4200100000:
           - fc00::81
@@ -346,7 +346,7 @@ configuration:
     tornum: 6
     bgp:
       router-id: 100.1.0.41
-      asn: 4200000000
+      asn: 4200000006
       peers:
         4200100000:
           - fc00::a1
@@ -364,7 +364,7 @@ configuration:
     tornum: 7
     bgp:
       router-id: 100.1.0.49
-      asn: 4200000000
+      asn: 4200000007
       peers:
         4200100000:
           - fc00::c1
@@ -382,7 +382,7 @@ configuration:
     tornum: 8
     bgp:
       router-id: 100.1.0.57
-      asn: 4200000000
+      asn: 4200000008
       peers:
         4200100000:
           - fc00::e1
@@ -400,7 +400,7 @@ configuration:
     tornum: 9
     bgp:
       router-id: 100.1.0.65
-      asn: 4200000000
+      asn: 4200000009
       peers:
         4200100000:
           - fc00::101
@@ -418,7 +418,7 @@ configuration:
     tornum: 10
     bgp:
       router-id: 100.1.0.73
-      asn: 4200000000
+      asn: 4200000010
       peers:
         4200100000:
           - fc00::121
@@ -436,7 +436,7 @@ configuration:
     tornum: 11
     bgp:
       router-id: 100.1.0.81
-      asn: 4200000000
+      asn: 4200000011
       peers:
         4200100000:
           - fc00::141
@@ -454,7 +454,7 @@ configuration:
     tornum: 12
     bgp:
       router-id: 100.1.0.89
-      asn: 4200000000
+      asn: 4200000012
       peers:
         4200100000:
           - fc00::161
@@ -493,7 +493,7 @@ configuration:
     tornum: 13
     bgp:
       router-id: 100.1.0.101
-      asn: 4200000000
+      asn: 4200000013
       peers:
         4200100000:
           - fc00::191
@@ -511,7 +511,7 @@ configuration:
     tornum: 14
     bgp:
       router-id: 100.1.0.109
-      asn: 4200000000
+      asn: 4200000014
       peers:
         4200100000:
           - fc00::1b1
@@ -529,7 +529,7 @@ configuration:
     tornum: 15
     bgp:
       router-id: 100.1.0.121
-      asn: 4200000000
+      asn: 4200000015
       peers:
         4200100000:
           - fc00::1e1
@@ -547,7 +547,7 @@ configuration:
     tornum: 16
     bgp:
       router-id: 100.1.0.129
-      asn: 4200000000
+      asn: 4200000016
       peers:
         4200100000:
           - fc00::201
@@ -565,7 +565,7 @@ configuration:
     tornum: 17
     bgp:
       router-id: 100.1.0.137
-      asn: 4200000000
+      asn: 4200000017
       peers:
         4200100000:
           - fc00::221
@@ -583,7 +583,7 @@ configuration:
     tornum: 18
     bgp:
       router-id: 100.1.0.145
-      asn: 4200000000
+      asn: 4200000018
       peers:
         4200100000:
           - fc00::241
@@ -601,7 +601,7 @@ configuration:
     tornum: 19
     bgp:
       router-id: 100.1.0.153
-      asn: 4200000000
+      asn: 4200000019
       peers:
         4200100000:
           - fc00::261
@@ -619,7 +619,7 @@ configuration:
     tornum: 20
     bgp:
       router-id: 100.1.0.161
-      asn: 4200000000
+      asn: 4200000020
       peers:
         4200100000:
           - fc00::281
@@ -637,7 +637,7 @@ configuration:
     tornum: 21
     bgp:
       router-id: 100.1.0.169
-      asn: 4200000000
+      asn: 4200000021
       peers:
         4200100000:
           - fc00::2a1
@@ -655,7 +655,7 @@ configuration:
     tornum: 22
     bgp:
       router-id: 100.1.0.177
-      asn: 4200000000
+      asn: 4200000022
       peers:
         4200100000:
           - fc00::2c1
@@ -673,7 +673,7 @@ configuration:
     tornum: 23
     bgp:
       router-id: 100.1.0.185
-      asn: 4200000000
+      asn: 4200000023
       peers:
         4200100000:
           - fc00::2e1
@@ -691,7 +691,7 @@ configuration:
     tornum: 24
     bgp:
       router-id: 100.1.0.193
-      asn: 4200000000
+      asn: 4200000024
       peers:
         4200100000:
           - fc00::301
@@ -709,7 +709,7 @@ configuration:
     tornum: 25
     bgp:
       router-id: 100.1.0.201
-      asn: 4200000000
+      asn: 4200000025
       peers:
         4200100000:
           - fc00::321
@@ -727,7 +727,7 @@ configuration:
     tornum: 26
     bgp:
       router-id: 100.1.0.209
-      asn: 4200000000
+      asn: 4200000026
       peers:
         4200100000:
           - fc00::341
@@ -745,7 +745,7 @@ configuration:
     tornum: 27
     bgp:
       router-id: 100.1.0.217
-      asn: 4200000000
+      asn: 4200000027
       peers:
         4200100000:
           - fc00::361
@@ -763,7 +763,7 @@ configuration:
     tornum: 28
     bgp:
       router-id: 100.1.0.225
-      asn: 4200000000
+      asn: 4200000028
       peers:
         4200100000:
           - fc00::381
@@ -781,7 +781,7 @@ configuration:
     tornum: 29
     bgp:
       router-id: 100.1.0.233
-      asn: 4200000000
+      asn: 4200000029
       peers:
         4200100000:
           - fc00::3a1
@@ -799,7 +799,7 @@ configuration:
     tornum: 30
     bgp:
       router-id: 100.1.0.241
-      asn: 4200000000
+      asn: 4200000030
       peers:
         4200100000:
           - fc00::3c1
@@ -817,7 +817,7 @@ configuration:
     tornum: 31
     bgp:
       router-id: 100.1.0.249
-      asn: 4200000000
+      asn: 4200000031
       peers:
         4200100000:
           - fc00::3e1
@@ -835,7 +835,7 @@ configuration:
     tornum: 32
     bgp:
       router-id: 100.1.1.1
-      asn: 4200000000
+      asn: 4200000032
       peers:
         4200100000:
           - fc00::401
@@ -853,7 +853,7 @@ configuration:
     tornum: 33
     bgp:
       router-id: 100.1.1.9
-      asn: 4200000000
+      asn: 4200000033
       peers:
         4200100000:
           - fc00::421
@@ -871,7 +871,7 @@ configuration:
     tornum: 34
     bgp:
       router-id: 100.1.1.17
-      asn: 4200000000
+      asn: 4200000034
       peers:
         4200100000:
           - fc00::441
@@ -889,7 +889,7 @@ configuration:
     tornum: 35
     bgp:
       router-id: 100.1.1.25
-      asn: 4200000000
+      asn: 4200000035
       peers:
         4200100000:
           - fc00::461
@@ -907,7 +907,7 @@ configuration:
     tornum: 36
     bgp:
       router-id: 100.1.1.33
-      asn: 4200000000
+      asn: 4200000036
       peers:
         4200100000:
           - fc00::481
@@ -925,7 +925,7 @@ configuration:
     tornum: 37
     bgp:
       router-id: 100.1.1.41
-      asn: 4200000000
+      asn: 4200000037
       peers:
         4200100000:
           - fc00::4a1
@@ -943,7 +943,7 @@ configuration:
     tornum: 38
     bgp:
       router-id: 100.1.1.49
-      asn: 4200000000
+      asn: 4200000038
       peers:
         4200100000:
           - fc00::4c1
@@ -961,7 +961,7 @@ configuration:
     tornum: 39
     bgp:
       router-id: 100.1.1.57
-      asn: 4200000000
+      asn: 4200000039
       peers:
         4200100000:
           - fc00::4e1
@@ -979,7 +979,7 @@ configuration:
     tornum: 40
     bgp:
       router-id: 100.1.1.65
-      asn: 4200000000
+      asn: 4200000040
       peers:
         4200100000:
           - fc00::501
@@ -997,7 +997,7 @@ configuration:
     tornum: 41
     bgp:
       router-id: 100.1.1.77
-      asn: 4200000000
+      asn: 4200000041
       peers:
         4200100000:
           - fc00::531
@@ -1015,7 +1015,7 @@ configuration:
     tornum: 42
     bgp:
       router-id: 100.1.1.85
-      asn: 4200000000
+      asn: 4200000042
       peers:
         4200100000:
           - fc00::551
@@ -1033,7 +1033,7 @@ configuration:
     tornum: 43
     bgp:
       router-id: 100.1.1.97
-      asn: 4200000000
+      asn: 4200000043
       peers:
         4200100000:
           - fc00::581
@@ -1051,7 +1051,7 @@ configuration:
     tornum: 44
     bgp:
       router-id: 100.1.1.105
-      asn: 4200000000
+      asn: 4200000044
       peers:
         4200100000:
           - fc00::5a1
@@ -1069,7 +1069,7 @@ configuration:
     tornum: 45
     bgp:
       router-id: 100.1.1.113
-      asn: 4200000000
+      asn: 4200000045
       peers:
         4200100000:
           - fc00::5c1
@@ -1087,7 +1087,7 @@ configuration:
     tornum: 46
     bgp:
       router-id: 100.1.1.121
-      asn: 4200000000
+      asn: 4200000046
       peers:
         4200100000:
           - fc00::5e1
@@ -1105,7 +1105,7 @@ configuration:
     tornum: 47
     bgp:
       router-id: 100.1.1.129
-      asn: 4200000000
+      asn: 4200000047
       peers:
         4200100000:
           - fc00::601
@@ -1123,7 +1123,7 @@ configuration:
     tornum: 48
     bgp:
       router-id: 100.1.1.137
-      asn: 4200000000
+      asn: 4200000048
       peers:
         4200100000:
           - fc00::621
@@ -1141,7 +1141,7 @@ configuration:
     tornum: 49
     bgp:
       router-id: 100.1.1.145
-      asn: 4200000000
+      asn: 4200000049
       peers:
         4200100000:
           - fc00::641
@@ -1159,7 +1159,7 @@ configuration:
     tornum: 50
     bgp:
       router-id: 100.1.1.153
-      asn: 4200000000
+      asn: 4200000050
       peers:
         4200100000:
           - fc00::661
@@ -1177,7 +1177,7 @@ configuration:
     tornum: 51
     bgp:
       router-id: 100.1.1.161
-      asn: 4200000000
+      asn: 4200000051
       peers:
         4200100000:
           - fc00::681
@@ -1195,7 +1195,7 @@ configuration:
     tornum: 52
     bgp:
       router-id: 100.1.1.169
-      asn: 4200000000
+      asn: 4200000052
       peers:
         4200100000:
           - fc00::6a1
@@ -1213,7 +1213,7 @@ configuration:
     tornum: 53
     bgp:
       router-id: 100.1.1.177
-      asn: 4200000000
+      asn: 4200000053
       peers:
         4200100000:
           - fc00::6c1
@@ -1231,7 +1231,7 @@ configuration:
     tornum: 54
     bgp:
       router-id: 100.1.1.185
-      asn: 4200000000
+      asn: 4200000054
       peers:
         4200100000:
           - fc00::6e1
@@ -1249,7 +1249,7 @@ configuration:
     tornum: 55
     bgp:
       router-id: 100.1.1.193
-      asn: 4200000000
+      asn: 4200000055
       peers:
         4200100000:
           - fc00::701
@@ -1267,7 +1267,7 @@ configuration:
     tornum: 56
     bgp:
       router-id: 100.1.1.201
-      asn: 4200000000
+      asn: 4200000056
       peers:
         4200100000:
           - fc00::721