From be9e06f6afb2391b4a0e1a7fff932ded8ef2ee55 Mon Sep 17 00:00:00 2001
From: Pearl Dsilva <pearl1594@gmail.com>
Date: Wed, 4 Oct 2023 17:50:57 -0400
Subject: [PATCH] reserve first IP (after g/w) of subnet for router nic - NSX

---
 .../java/com/cloud/network/IpAddressManagerImpl.java   | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/server/src/main/java/com/cloud/network/IpAddressManagerImpl.java b/server/src/main/java/com/cloud/network/IpAddressManagerImpl.java
index c85328807df..b5829d5619e 100644
--- a/server/src/main/java/com/cloud/network/IpAddressManagerImpl.java
+++ b/server/src/main/java/com/cloud/network/IpAddressManagerImpl.java
@@ -2044,6 +2044,9 @@ public class IpAddressManagerImpl extends ManagerBase implements IpAddressManage
         if (requestedIp != null) {
             return this.acquireGuestIpAddress(network, requestedIp);
         }
+        if ("NsxGuestNetworkGuru".equals(network.getGuruName())) {
+            return getRouterIp(network.getGateway());
+        }
         String placementConfig = VrouterRedundantTiersPlacement.valueIn(network.getAccountId());
         IpPlacement ipPlacement = IpPlacement.fromString(placementConfig);
         switch (ipPlacement) {
@@ -2055,6 +2058,13 @@ public class IpAddressManagerImpl extends ManagerBase implements IpAddressManage
         return this.acquireGuestIpAddress(network, null);
     }
 
+    private String getRouterIp(String gatewayIp) {
+        int i = gatewayIp.lastIndexOf('.');
+        String ipPart1 = gatewayIp.substring(0, i);
+        int ipLastOctect = Integer.parseInt(gatewayIp.substring(i+1)) + 1;
+        return ipPart1.concat("." + ipLastOctect);
+    }
+
     /**
      * Get the list of public IPs that need to be applied for a static NAT enable/disable operation.
      * Manipulating only these ips prevents concurrency issues when disabling static nat at the same time.