question

Sandeep-6822 avatar image
0 Votes"
Sandeep-6822 asked RaviVarmanMSFT-5919 answered

Unable to access my Web Site through Load balancer

I am not able to access my web site that is behind a load balancer and hosted on a VMSS.
Error:
Gateway Timeout
Server error - server 20.102.123.211 is unreachable at this moment.

Please retry the request or contact your administrator.

Setup:
VMSS with one instance. IIS installed.
Inbound Port 80 allowed
Added to backend pool of load balancer
Load balancer rule created for port 80

azure-load-balancerazure-virtual-machines-scale-set
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1 Answer

RaviVarmanMSFT-5919 avatar image
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RaviVarmanMSFT-5919 answered

Hi @Sandeep-6822

Thanks for reaching!
- Check the service is running on your VMSS instances i.e port 80 listening or not using "netstat -ano" in command prompt, if it is not listening then you see it fails
- If it is Linux VM then check listening along with that check if any block on IP tables which blocks port 80
- LB will not forward traffic to the backend when health probe fails, check if there is NSG on NIC level or Subnet level of the VMSS instances, verify if you have block for Azure Loadbalancer Tag or not, if you have any deny rule then add a rule on NSG to allow source as Azure loadbalancer Tag as incoming
- Check if any route table associated with the subnet of VMSS instances, if it is taking custom route apart from default route to internet , check the next hope defined if any block on your Virtual appliance/Firewall

Ref: https://docs.microsoft.com/en-us/azure/load-balancer/troubleshoot-rhc

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

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