Hi On many links regarding user space hanlding of packets I have read warnings about using libipq, speed wise .... "do this only if u dont want ultra high speeds and all" ... this speed issue arises because we need to copy things from kernel space to usr space and vice versa, or is there any other reason for this. I mean suppose i want to make a process that gets the packets from the kernel and plays with them and then reinjects them into the kernel( my process has to be in user space) ... keeping this constraint in mind (the process that tinkers with the packets has to be in user space), is there any faster solution than using libipq i.e do these warnings just mean that using libipq gives slower results when if packet mangling is done in the kernel space itself .. which is quite obvious, or do they mean that we can have better ways(faster) than libipq for user space packet mangling. thanks Amit "DISCLAIMER: This message is proprietary to Hughes Software Systems Limited (HSS) and is intended solely for the use of the individual to whom it is addressed. It may contain privileged or confidential information and should not be circulated or used for any purpose other than for what it is intended. If you have received this message in error, please notify the originator immediately. If you are not the intended recipient, you are notified that you are strictly prohibited from using, copying, altering, or disclosing the contents of this message. HSS accepts no responsibility for loss or damage arising from the use of the information transmitted by this email including damage from virus."