Re: MTU/MSS testing IPv6

2016-05-26 Thread Matthew Luckie
On 05/26/16 00:33, Ignatios Souvatzis wrote: > On Fri, Apr 29, 2016 at 08:30:50AM +0200, Mikael Abrahamsson wrote: >> >> Hi, >> >> I've run into a scenario where a website doesn't seem to be listening to >> PTB. I can reach them just fine from an MTU1500 clean IPv6 connection, but >> if I reach

Re: MTU/MSS testing IPv6

2016-05-25 Thread Brian E Carpenter
On 26/05/2016 00:33, Ignatios Souvatzis wrote: > On Fri, Apr 29, 2016 at 08:30:50AM +0200, Mikael Abrahamsson wrote: >> >> Hi, >> >> I've run into a scenario where a website doesn't seem to be listening to >> PTB. I can reach them just fine from an MTU1500 clean IPv6 connection, but >> if I reach

Re: MTU/MSS testing IPv6

2016-05-25 Thread Ignatios Souvatzis
On Fri, Apr 29, 2016 at 08:30:50AM +0200, Mikael Abrahamsson wrote: > > Hi, > > I've run into a scenario where a website doesn't seem to be listening to > PTB. I can reach them just fine from an MTU1500 clean IPv6 connection, but > if I reach from a MTU1500<->MTU1480<->MTU1500 connection, it

Re: MTU/MSS testing IPv6

2016-04-29 Thread Erik Nygren
As for testing tools, scamper is the only one I've found when I last looked (in 2014?) it doesn't support running on Linux out of the box. http://wand.net.nz/scamper/pmtud For example, you can do: sudo scamper -F ipfw -I "tbit -M 1280 -t pmtud -S $sourceip -u $url" $targetip Where $url has to

Re: MTU/MSS testing IPv6

2016-04-29 Thread Gert Doering
Hi, On Fri, Apr 29, 2016 at 09:38:50AM +0200, Shane Kerr wrote: > OTOH, blocking all IPv6 fragments seems a bit too aggressive for > firewalls. My guess is more along the lines of "this is on FreeBSD, using the pf(4) packet filter, which is still not able to do anything reasonable with IPv6

Re: MTU/MSS testing IPv6

2016-04-29 Thread Shane Kerr
Seth, At 2016-04-29 08:43:09 +0200 Seth Mos wrote: > Op 29-4-2016 om 8:30 schreef Mikael Abrahamsson: > > > > Site B which sends all data packets as fragments. This is most likely > > because they have some kind of AFTR where the IPv4 side has MTU1500 and > > the IPv6 side has

Re: MTU/MSS testing IPv6

2016-04-29 Thread Eric Vyncke (evyncke)
See also RFC 6946 on this topic and the more controversial draft-ietf-6man-deprecate-atomfrag-generation -éric On 29/04/16 08:43, "ipv6-ops-bounces+evyncke=cisco@lists.cluenet.de on behalf of Seth Mos" wrote:

Re: MTU/MSS testing IPv6

2016-04-29 Thread Seth Mos
Op 29-4-2016 om 8:30 schreef Mikael Abrahamsson: > Hi, > > Site B which sends all data packets as fragments. This is most likely > because they have some kind of AFTR where the IPv4 side has MTU1500 and > the IPv6 side has MTU1320 or something like that. The site cbs.nl does this as well. It's

MTU/MSS testing IPv6

2016-04-29 Thread Mikael Abrahamsson
Hi, I've run into a scenario where a website doesn't seem to be listening to PTB. I can reach them just fine from an MTU1500 clean IPv6 connection, but if I reach from a MTU1500<->MTU1480<->MTU1500 connection, it doesn't work. I don't get the big packets after SYN handshake. I've been