We are having a very strange issue with one of our clients, they have recently had a new EFM (leased line) installed and ever since utilising this conenction they are no longer able to use an FTP service on their accounting/logistics software. They now have a 20 seconds delay from requesting FTP to gaining a login prompt and this length of time means a login timeout. I have included a link to the filtered pcap and you can see the delay in response. Can somebody help here and suggest where this delay is coming from/how we can find out more information about where the delay is coming from? Do you have any suggestions at all. ISP are washing their hands and have stated its not happening on their network. The FTP hosts are also pulling the same line while the customer sits in the middle with no FTP connection
Any further info can be provided (tracerts etc)
This is not a DNS issue as we have tested direct to the public IP with the same results.