On 26 September 2013 14:13, James Harper <[email protected]> wrote: >> However for some reason path MTU discovery has completely broken when >> using the newer modem. >> The primary Linux box is fine, but all clients (whether wired, >> wireless *or even virtual*) fail to work unless I manually set their >> interfaces to an mtu of 1492. >> > > Is it outbound or inbound MTU path discovery that isn't working? Or both?
Hmm, possibly inbound, now you mention it.. I was testing by attempting to curl web pages or images, and didn't try sending anything outbound at the time. > I've had to set MRU explicitly before to get things working properly, > although I don't see why the different modem would make a different, unless it was using baby jumbo frames or something. Both models are 10/100 ethernet only. > What does 'ip link show dev ppp0' say? Is MTU definitely 1492 in there? Yes, definitely 1492 mtu listed there. > What happens when a client computer tries to send a larger packet? Does your > Linux router send a 'frag required' response? If I'm reading the tcpdump correctly (see reply to myself with it this morning) then yes, there is a frag-required response. T _______________________________________________ luv-main mailing list [email protected] http://lists.luv.asn.au/listinfo/luv-main
