Hi Abhijeet,
On Tue, Apr 13, 2010 at 12:39 PM, Abhijit Bhopatkar <[email protected]>wrote: > > 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 > > > 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 > Thanks for your suggestions. In the context of what you mentioned about the chain of backlog packets building up at the router: If a router cannot handle the size of a packet it receives, will it drop the packet, or will it try to fragment it? If I understand the above passage correctly, what you are suggesting is, if a router cannot handle large packets, it is going to cause re-transmissions and very soon the network will become sluggish. In this case will that router become a bottleneck for the entire LAN connected through it? The reason I ask this is because, if I am able to determine that the router is not becoming a bottleneck for the entire network, then would it be safe to say that the router is probably not responsible for mis-handling large packets? Thanks... your suggestion for creating a script '/etc/NetworkManager/dispatcher/d02mtu' worked very well. -- Thanks & Regards Parag Shah http://blog.adaptivesoftware.biz _______________________________________ Pune GNU/Linux Users Group Mailing List
