ExpressRoute route filters for regions

Eamonn Keating 41 Reputation points
2021-06-05T22:53:12.753+00:00

Hi All,
When managing rules in ExpressRoute filters for allowed service communities there are 4 categories : Region, Storage, SQL, Cosmos and backup. If Region is selected does that mean that all SaaS services excluding Storage, SQL, Cosmos and backup are routed through ExpressRoute? Are these data services separated due to the potentially large volume?
Also is there any way to check that data is flowing through ExpressRoute for a specific service e.g. SQL(other than checking the filters)?
Thanks
Eamonn

Azure ExpressRoute
Azure ExpressRoute
An Azure service that provides private connections between Azure datacenters and infrastructure, either on premises or in a colocation environment.
342 questions
0 comments
Accepted answer
  1. RaviVarmanMSFT 626 Reputation points Microsoft Employee
    2021-06-09T13:34:53.197+00:00

    Hi @Eamonn Keating

    When you select Regional BGP community all public IP ranges related to that location will be advertised which covers Storage, SQL, Cosmos and Backup BGP community as well. You can use Get-AzBgpServiceCommunity command to get all the IP details. The services are separated to avoid a large number of prefixes gets advertised through BGP. The large number of prefixes significantly increases the size of the route tables maintained by routers within your network.

    EX: If you are utilising only SQL services then no need to select Regional BGP community which advertise large number of routes, rather you can choose only SQL BGP community and Microsoft will advertise only subset of IP ranges with respect to SQL services. By this you can avoid unnecessary routes and significantly decrease the size of the route tables maintained by your routers.

    If you want Microsoft 365 services such as Exchange Online, SharePoint Online, and Skype for Business IP's to be advertised then enabled those services in Router filter as well in addition with Regional or SQL BGP community.

    Simple test to check the traffic flowing through Expressroute is to do tracert from your onprem source machine. Ex: tracert sqlservername.database.windows.net.

    When you create Microsoft peering you might have provided primary and secondary subnets, from each of these subnets, you will assign the first usable IP address to your router and second usable IP for Microsoft(MSEE). When you do tracert you should be seeing the IP of MSEE, if yes then it is taking expressroute path, if you dont see the IP of MSEE the it is not taking expressroute path.

    You can refer network performance monitor as well for additional monitoring capabilities
    https://video2.skills-academy.com/en-us/azure/expressroute/how-to-npm

    Hope this was helpful. Please let us know in case of any additional questions or concerns.

    Please "Accept the answer" if the information helped you. This will help us and others in the community as well

0 additional answers

Sort by: Most helpful
Most helpful Newest Oldest