Fix invalid links

Author: rachel-msft

articles/mariadb/concepts-security.md

@@ -46,4 +46,4 @@ You can opt in to [Advanced Threat Protection](concepts-data-access-and-security
 
 
 ## Next steps
-- Enable firewall rules for [IPs](concepts-firewall-rules.md) or [virtual networks](concepts-data-access-and-security-vnet.md)
+- Enable firewall rules for [IPs](concepts-firewall-rules.md) or [virtual networks](concepts-data-access-security-vnet.md)

articles/mysql/TOC.yml

@@ -88,7 +88,7 @@
     - name: Firewall rules
       href: concepts-firewall-rules.md
     - name: Virtual Network
-      href: concepts-data-access-security-vnet.md
+      href: concepts-data-access-and-security-vnet.md
     - name: Advanced Threat Protection
       href: concepts-data-access-and-security-threat-protection.md   
   - name: Business continuity

articles/mysql/concepts-security.md

@@ -30,7 +30,7 @@ A newly created Azure Database for MySQL server has a firewall that blocks all e
 IP firewall rules grant access to servers based on the originating IP address of each request. See the [firewall rules overview](concepts-firewall-rules.md) for more information.
 
 ### Virtual network firewall rules
-Virtual network service endpoints extend your virtual network connectivity over the Azure backbone. Using virtual network rules you can enable your Azure Database for MySQL server to allow connections from selected subnets in a virtual network. For more information, see the [virtual network service endpoint overview](concepts-data-access-security-vnet.md).
+Virtual network service endpoints extend your virtual network connectivity over the Azure backbone. Using virtual network rules you can enable your Azure Database for MySQL server to allow connections from selected subnets in a virtual network. For more information, see the [virtual network service endpoint overview](concepts-data-access-and-security-vnet.md).
 
 
 ## Access management