I'm having a problem here at work. We have two web servers that are both configured for network load balancing using Microsoft's NLB solution. Each server has two physical NICs. one nic on each server has its stically assigned ip and the ip of the cluster. the other nic has just a statically assigned ip.
We are getting complaints from customers that when they click on our promotional e-mails we send out that they receive a "Bad Request" message. The problem is I can't seem to reproduce the problem, I've tried clicking off the same email at home and at work on different computers and it works fine.
I've checked the HTTPERR logs on both machines and they are both registering BadRequest messages. Here is an example:
2010-09-10 19:24:59 69.xxx.x.xx 62121 (Cluster IP HERE) 80 HTTP/1.1 GET /default.aspx?ref_code=SP082610&utm_source=bronto&utm_medium=email&utm_term=Image+-+COMPANYNAME+%26+COMPANYNAME&utm_content=Online+Newsletter+August+2010+%E2%80%93+Olive+Oil+Reality&utm_campaign=Online+Newsletter+August+2010+%E2%80%93+Olive+Oil+Reality 400 - BadRequest -
The only thing I can think of is the url contains "%" in the url. Which is weird, because the url in the actual email doesnt. So that means their e-mail hosting provider is transforming the url somehow. Anyone have any ideas?
Also, it only seems to be happening to a small percentage of the people we send emails to. We still get a lot of orders from the emails so I know its working for most people.