Ray Van Dolson wrote: > On Thu, May 10, 2007 at 07:04:51PM +0100, Plant, Dean wrote: >> Weird... Tell me about it, I spent a lot of time head scratching >> trying to figure out why network connections would just mysteriously >> hang. Eventually found reference to a problem with >> tcp_window_scaling and firewalls and after disabling >> tcp_window_scaling on my test CentOS 5 box, everything started >> working. >> >> The install does not get far enough for the shell console to be >> available, it hangs at the transferring stage2.img. >> > > Ah, probably before %pre even has run (?) Well you could rebuild the > kernel on the install CD to disable window scaling by default. :) Ok, > not a particularly useful option... maybe someone else will have a > suggestion. > > In HP-UX you can pass kernel parameters at boot-time, I wonder if > anything similar could be done? Probably not. > > Have you captured a tcpdump of what happens when the "freeze" occurs > with an intermediary system? Maybe a setting could be changed on your > switch? Although I would doubt the switch would be a factor. Are > your packets going through an intermediary router? > > I plan to do some network installs of CentOS 5 soon, will be > interesting to see if this issue occurs. > I don't think this is a issue with CentOS/RHEL. The kickstart in this instance is passing through a firewall appliance, which I think is Open/FreeBSD based and we now believe is breaking tcp window scaling. It seems that CentOS3&4 was unaffected by this but with v5 network connections hang after transferring about 500k. On a network that does not pass through this firewall v5 works as expected. Dean