> 1. Even though I understand that the VPN server adds headers and hence the > need to lower the MTU, I cannot understand why communication stalls when I > talk to CVS in such a situation, and it does not stall with regular internet > traffic.
The cvs will have a huge bulk traffic going in and out. The main problem with MTU is not at server or client side, but is usually in the middle, the routers. The problem is that some routers on the network are not able to handle large packets very well. They start building up huge chains of backlog packets and eventually cause TCP retransmissions. The problem keeps aggravating very quickly and within seconds the network traffic for that particular connection starts grounding to halt. Addition of VPN on top of CVS might just be tipping the sizes beyond the trigger point for your network setup. The problem is typically intense when a cheap router is being used to share a broadband connection on LAN. This is just a guess, all the network guru's thrash me if i am wrong :p > 2. I tried adding a script to my profile.d which would set the MTU for wlan0 > and eth0 to 1200. However, this does not seem to have any effect. So I have > to set the MTU manually everytime I boot into the machine. Could this be > becasue the network interfaces are not in a state to be configured at the > time scripts in profile.d are run? The Network manager might be resetting the interfaces, you can add scripts in /etc/NetworkManager/dispatcher.d instead to set the MTU on connection UP or DOWN for every interface. Take a look at 01ifupdown script as an example you should add 02MTU or something like that. BTW you could also use the if-updown scripts as being invoked from 01ifupdown. I never used them so don't know how those work. BAIN _______________________________________ Pune GNU/Linux Users Group Mailing List
