edit pass: expressroute-troubleshooting-expressroute-overview

Author: ShawnJackson

articles/expressroute/expressroute-troubleshooting-expressroute-overview.md

@@ -44,7 +44,7 @@ In the preceding diagram, the numbers indicate key network points:
 
 At times, this article references these network points by their associated number. 
 
-Depending on the ExpressRoute connectivity model, network points 3 and 4 might be switches (Layer 2 devices) or routers (Layer 3 devices). The ExpressRoute connectivity models are cloud exchange co-location, point-to-point Ethernet connection, or any-to-any (IPVPN). 
+Depending on the ExpressRoute connectivity model, network points 3 and 4 might be switches (layer 2 devices) or routers (layer 3 devices). The ExpressRoute connectivity models are cloud exchange co-location, point-to-point Ethernet connection, or any-to-any (IPVPN). 
 
 In the direct connectivity model, there are no network points 3 and 4. Instead, CEs (2) are directly connected to MSEEs via dark fiber.
 
@@ -53,13 +53,13 @@ If the cloud exchange co-location, point-to-point Ethernet, or direct connectivi
 If the any-to-any (IPVPN) connectivity model is used, PE-MSEEs (4) establish BGP peering with MSEEs (5). PE-MSEEs propagate the routes received from Microsoft back to the customer network via the IPVPN service provider network.
 
 > [!NOTE]
-> For high availability, Microsoft establishes a fully redundant parallel connectivity between MSEE/PE-MSEE pairs. A fully redundant parallel network path is also encouraged between the customer network and PE/CE pairs. For more information about high availability, see the article [Designing for high availability with ExpressRoute][HA].
+> For high availability, Microsoft establishes a fully redundant parallel connectivity between MSEE and PE-MSEE pairs. A fully redundant parallel network path is also encouraged between the customer network and PE/CE pairs. For more information about high availability, see the article [Designing for high availability with ExpressRoute][HA].
 
 The following sections represent the logical steps in troubleshooting an ExpressRoute circuit.
 
 ## Verify circuit provisioning and state
 
-Provisioning an ExpressRoute circuit establishes a redundant Layer 2 connection between CEs/PE-MSEEs (2/4) and MSEEs (5). For more information on how to create, modify, provision, and verify an ExpressRoute circuit, see the article [Create and modify an ExpressRoute circuit][CreateCircuit].
+Provisioning an ExpressRoute circuit establishes a redundant layer 2 connection between CEs/PE-MSEEs (2/4) and MSEEs (5). For more information on how to create, modify, provision, and verify an ExpressRoute circuit, see the article [Create and modify an ExpressRoute circuit][CreateCircuit].
 
 >[!TIP]
 >A service key uniquely identifies an ExpressRoute circuit. If you need assistance from Microsoft or from an ExpressRoute partner to troubleshoot an ExpressRoute issue, provide the service key to readily identify the circuit.
@@ -154,7 +154,7 @@ In the preceding example, Azure private peering is provisioned, but Azure public
 > [!NOTE]
 > If enabling a peering fails, check if the assigned primary and secondary subnets match the configuration on the linked CE/PE-MSEE. Also check if the correct `VlanId`, `AzureASN`, and `PeerASN` values are used on MSEEs, and if these values map to the ones used on the linked CE/PE-MSEE. 
 >
-> If MD5 hashing is chosen, the shared key should be the same on MSEE and the PE-MSEE/CE pair. Previously configured shared keys would not be displayed for security reasons. 
+> If MD5 hashing is chosen, the shared key should be the same on MSEE and CE/PE-MSEE pairs. Previously configured shared keys would not be displayed for security reasons. 
 >
 > If you need to change any of these configurations on an MSEE router, see [Create and modify routing for an ExpressRoute circuit][CreatePeering].
 
@@ -219,7 +219,7 @@ At line:1 char:1
 > [!NOTE]
 > If enabling a peering fails, check if the assigned primary and secondary subnets match the configuration on the linked CE/PE-MSEE. Also check if the correct `VlanId`, `AzureASN`, and `PeerASN` values are used on MSEEs, and if these values map to the ones used on the linked CE/PE-MSEE. 
 > 
-> If MD5 hashing is chosen, the shared key should be the same on MSEE and the PE-MSEE/CE pair. Previously configured shared keys would not be displayed for security reasons. 
+> If MD5 hashing is chosen, the shared key should be the same on MSEE and CE/PE-MSEE pairs. Previously configured shared keys would not be displayed for security reasons. 
 >
 > If you need to change any of these configurations on an MSEE router, see [Create and modify routing for an ExpressRoute circuit][CreatePeering]. 
 
@@ -234,9 +234,9 @@ The Address Resolution Protocol (ARP) table provides a mapping of the IP address
 * Mapping of the IP address for the ExpressRoute router interface to the MAC address
 * Age of the mapping
 
-ARP tables can help validate Layer 2 configuration and troubleshoot basic Layer 2 connectivity issues.
+ARP tables can help validate layer 2 configuration and troubleshoot basic layer 2 connectivity issues.
 
-To learn how to view the ARP table of an ExpressRoute peering and how to use the information to troubleshoot Layer 2 connectivity issues, see [Getting ARP tables in the Resource Manager deployment model][ARP].
+To learn how to view the ARP table of an ExpressRoute peering and how to use the information to troubleshoot layer 2 connectivity issues, see [Getting ARP tables in the Resource Manager deployment model][ARP].
 
 ## Validate BGP and routes on the MSEE
 
@@ -269,7 +269,7 @@ Path    : 123##
 ```
 
 > [!NOTE]
-> If the state of a eBGP peering between an MSEE and a CE/PE-MSEE is **Active** or **Idle**, check if the assigned primary and secondary peer subnets match the configuration on the linked CE/PE-MSEE. Also check if the correct `VlanId`, `AzureASN`, and `PeerASN` values are used on MSEEs, and if these values map to the ones used on the linked PE-MSEE/CE. If MD5 hashing is chosen, the shared key should be the same on MSEE and the CE/PE-MSEE pair. If you need to change any of these configurations on an MSEE router, see [Create and modify routing for an ExpressRoute circuit][CreatePeering].
+> If the state of a eBGP peering between an MSEE and a CE/PE-MSEE is **Active** or **Idle**, check if the assigned primary and secondary peer subnets match the configuration on the linked CE/PE-MSEE. Also check if the correct `VlanId`, `AzureASN`, and `PeerASN` values are used on MSEEs, and if these values map to the ones used on the linked CE/PE-MSEE. If MD5 hashing is chosen, the shared key should be the same on MSEE and CE/PE-MSEE pairs. If you need to change any of these configurations on an MSEE router, see [Create and modify routing for an ExpressRoute circuit][CreatePeering].
 
 > [!NOTE]
 > If certain destinations are not reachable over a peering, check the route table of the MSEEs for the corresponding peering context. If a matching prefix (could be NATed IP) is present in the routing table, then check if any firewalls, network security groups, or access control lists (ACLs) on the path are blocking the traffic.
@@ -321,7 +321,7 @@ Test your private peering connectivity by counting packets arriving at and leavi
 
     :::image type="content" source="./media/expressroute-troubleshooting-expressroute-overview/connectivity-issues.png" alt-text="Screenshot of the option for connectivity issues.":::
 
-1. In the **Tell us more about the problem you are experiencing** dropdown list, select **Connectivity to Azure Private, Azure Public or Dynamics 365 services**.
+1. In the **Tell us more about the problem you are experiencing** dropdown list, select **Connectivity to Azure Private, Azure Public or Dynamics 365 Services**.
 
     :::image type="content" source="./media/expressroute-troubleshooting-expressroute-overview/tell-us-more.png" alt-text="Screenshot of the dropdown option for the problem that the user is experiencing.":::
 
@@ -339,7 +339,7 @@ Test your private peering connectivity by counting packets arriving at and leavi
 
 When your results are ready, you'll have two sets of them for the primary and secondary MSEE devices. Review the number of matches in and out, and use the following scenarios to interpret the results:
 
-* **You see packet matches sent and received on both MSEEs**: This result indicates healthy traffic inbound to and outbound from the MSEE on your circuit. If loss is occurring either on-premises or in Azure, it's happening downstream from the MSEE.
+* **You see packet matches sent and received on both MSEEs**: This result indicates healthy traffic inbound to and outbound from the MSEEs on your circuit. If loss is occurring either on-premises or in Azure, it's happening downstream from the MSEEs.
 * **If you're testing PsPing from on-premises to Azure, received results show matches, but sent results show no matches**: This result indicates that traffic is coming in to Azure but isn't returning to on-premises. Check for return-path routing issues. For example, are you advertising the appropriate prefixes to Azure? Is a user-defined route (UDR) overriding prefixes?
 * **If you're testing PsPing from Azure to on-premises, sent results show no matches, but received results show matches**: This result indicates that traffic is coming in to on-premises but isn't returning to Azure. Work with your provider to find out why traffic isn't being routed to Azure via your ExpressRoute circuit.
 * **One MSEE shows no matches, but the other shows good matches**: This result indicates that one MSEE isn't receiving or passing any traffic. It might be offline (for example, BGP/ARP is down).
@@ -371,7 +371,7 @@ During a maintenance period, performance of the virtual network gateway might be
 
     :::image type="content" source="./media/expressroute-troubleshooting-expressroute-overview/performance-issues.png" alt-text="Screenshot of selecting the option for performance issues.":::
 
-1. Wait for the diagnostics to run and interpret the results:
+1. Wait for the diagnostics to run and interpret the results.
 
     :::image type="content" source="./media/expressroute-troubleshooting-expressroute-overview/gateway-result.png" alt-text="Screenshot of the diagnostic results.":::