AWS Cisco CSR, problem with MS SQL query packets

[kirk_bollinger]

Hello,

We have deployed CSR's acting as transit routers in AWS. IPsec tunnels to VPC's and GRE tunnels back to Cisco ASR's on prem. We have a java app in a vpc using a MS SQL DB on prem which starts the SQL connection by sending a 1 byte UDP payload packet to the SQL server. The SQL server is supposed to respond with TCP  connection parameters. The problem is the CSR is not properly forwarding the 1 bye udp payload packets. We crafted 2 byte and larger packets and they work fine. Anyone have any ideas? We have erspaned the 1 byte packets and narrowed the problem to the CSRs. We are running Cisco IOS XE Software, Version 16.03.01a.

thanks!

-kirk

[kirk_bollinger]

Actually I was able to capture the packet leaving the CSR using the monitor capture feature so this is now a provider issue.

29   43    7.319991   10.252.112.116   ->  172.22.26.43     0  BE   UDP

  0000:  00000000 00000000 00000000 08004500   ..............E.

  0010:  001D2F6B 4000FD11 0CB30AFC 7074AC16   ../k@.......pt..

  0020:  1A2B97B0 059A0009 E1DF3F              .+........?