"502 bad gateway" response with L7 transparent mode
Article ID: 336810
Updated On:
Products
VMware NSX
Issue/Introduction
Symptoms:
1. Client receive 502 bad gateway response
2. Under edge syslog we see "99: Cannot assign requested address" errors
1. Client receive 502 bad gateway response
2. Under edge syslog we see "99: Cannot assign requested address" errors
Environment
VMware NSX-T Data Center 2.x
VMware NSX-T Data Center
VMware NSX-T Data Center
Cause
This is a timing issue.
With only "l7 transparent mode", LB will use same client IP and port to connect to selected backend server for each http request comes from that client connection. There's a chance that, 2 http requests from same connection are allocated with same backend server, which triggers connections to that server with same IP and port. If the previous connection exists or doesn't quit completely, 99 error is reported with "cannot assign the address" then 502 response is replied.
With only "l7 transparent mode", LB will use same client IP and port to connect to selected backend server for each http request comes from that client connection. There's a chance that, 2 http requests from same connection are allocated with same backend server, which triggers connections to that server with same IP and port. If the previous connection exists or doesn't quit completely, 99 error is reported with "cannot assign the address" then 502 response is replied.
Resolution
Fixed in NSX-T 3.1.1 and later
Workaround:
1. Enable SNAT by configuring “SNAT Translation Mode” to “Automap” or “IP Pool” based on the requirement.
2. User x-forwarded-for if client IP needs to be visible to backend devices.
Workaround:
1. Enable SNAT by configuring “SNAT Translation Mode” to “Automap” or “IP Pool” based on the requirement.
2. User x-forwarded-for if client IP needs to be visible to backend devices.
Feedback
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