Disclaimer

The content of this material are challenges faced onsite and how I personally resolved them. Please be noted that solutions posted here

1> should not be considered as ultimate. The material may be considered for reference only.

2> should not be considered as guarantee that solutions may work. Contact Cyberoam support before making any changes.

3> blog does NOT belong to the Cyberoam. It's a blog...a personal blog.

Changes done after referring this site may seriously damage the network. So...

........DO CHANGES AT YOUR OWN RISK

(please contact cyberoamsupport before implementing any changes)

Friday, 2 December 2011

Website with keepalives

Issue: A website was sending keep alives but after 5 min the website timed out and the users was logged out.

Details: A webiste was hosted outside the network. Users from inside the network were trying to access this website. On close observation of the packets we found that the browser was sending the packets to the website which was keep alive packet after every 5 mins. However the site was sending a FIN packet.

Resolution: At first we thought that the issue was at the website end. Because the website was gracefully finishing the connection. But on close observation we found the following

1> The SYN packet to initiate the connection was sent with ISP1 IP address
2> The keep alive packet was set with ISP2 IP address.

The connection was load balanced. But since the website was not having any connection already with ISP2 IP address it simply sent the FIN packet.

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