similar to: MTU, PMTU & DF flag

On Thu, May 14, 2015 at 10:12:40AM +0200, Florent B wrote: > > I have no experience with Ubuntu, but I find it hard to believe it would > > block ICMP Fragmentation Needed packets out of the box. > > I can confirm you that this is the case. Ubuntu ignores those ICMP > packets... :( (rp_filter settings) > > You can see it here : https://mellowd.co.uk/ccie/?p=5662

On Thu, May 14, 2015 at 10:12:40 +0200, Florent B wrote: > On 05/13/2015 05:00 PM, Guus Sliepen wrote: > > I have no experience with Ubuntu, but I find it hard to believe it would > > block ICMP Fragmentation Needed packets out of the box. > > I can confirm you that this is the case. Ubuntu ignores those ICMP > packets... :( (rp_filter settings) > > You can see it

Hi all, I have two nodes, connected to a switch, using Tinc 1.1 from git. They connect each other with sptps, and to other nodes in the Internet with old protocol because they have Tinc 1.0. There is no problem with remote nodes, but between my 2 local nodes, they see 1518 PMTU. But local network is 1500 MTU !!! So nodes can ping each other but larger data does not go. test1=sllm1 test2=sllm2

+0100 From: Daniel Schall <tinc-devel at mon-clan.de> Date: Thu, 6 Jan 2011 17:00:35 +0100 Subject: [PATCH] Improved PMTU discovery diff --git a/lib/dropin.c b/lib/dropin.c index 52fb5b8..2b803b1 100644 --- a/lib/dropin.c +++ b/lib/dropin.c @@ -165,8 +165,8 @@ #endif =20 #ifdef HAVE_MINGW -int usleep(long usec) { - Sleep(usec / 1000); - return 0; -} +//int usleep(long usec) { +//

Hi Guus, while checking the source code, I stumbled upon PMTU Discovery. I've got a question regarding the process of sending/receiving PMTU packets. As I understand, the packet flow is like this: 1 .Tinc creates a packet with a specific payload length to send it as an PMTU probe. (The data part is just some random bytes.) 2. This packet gets compressed and sent

Hello Tinc list! I'm trying to set up a Tinc VPN between two KVM host machines so that a VM on one host can communicate with a VM on the other host. While I do have a good bit of experience with virtualization, I'm not a particularly savvy network guy, so this is proving to be a pretty big challenge. Requirements: * ALL VM network traffic must be secure. * VMs on one host must be

Dear Guus, while improving the PMTU Discovery algorithm, I found the following behavior in the method "send_udppacket": 1) The code checks, whether the data size is smaller than the MTU, thus if it fits into a single UDP packet. If not, you send the packet via TCP. 2) The data is compressed, changing its size. (Usually, making it smaller, but that's not always

Dear Guus, I've attached my first git commit to your repository. It does not contain any new functionalities, but it is a first try to interact with your git copy. Could you please verify, if you can push this commit to your repository? If it works, I'll send you the rest of my work, which contains: 1) some small improvements in logging (using flags instead of counters) 2) the

Hallo, I have a couple of tinc hosts in the same network, some using the latest tinc 1.1 git and some using 1.0.24. It seems like traffic between 1.1 and 1.0 nodes is always transfered using TCP (and an intermediate node, if not directly connected), never with UDP. Viewed from host W (tinc 1.1): (All after successfully pinging an IP behind the remote side to trigger UDP path probing, and

Hi there, I am experiencing an annoying but not critical issue with (I think) tinc's internal routing. My setup is this: HostA (local. ConnectTo = HostC) HostB (geographically close. ConnectTo = HostC) HostC (far away. ConnectTo = nothing) Without tinc, pings from HostA to HostB take around 10ms, and from HostA/B to HostC around 200ms. With tinc, pings from HostA to HostB take nearly

Hello, all! I have many questions about tap device architecture. What is a right way to calc mtu on TAP device to avoid fragmentation on real eth device? I suppose TAP MTU = 1500-8(UDP)-20(IP)-18(Ethernet) = 1454. So I'd set 1454 for tap device: "ip link set mtu 1454 dev eth0" I'm not shure about what is the exact size of ethernet frame header, which tap device use in switch

Hi, I'm sometimes getting a failure of connecting 2 nodes when Tinc is started and configured in a LAN. In the logs, there are some unexpected dropped packets with very high or negative seq. I can reproduce this issue ~2% of the time. When this happens, the 2 nodes can no longer ping or ssh each other through the tunnel interface but using eth0 works fine. The connection can recover after at

We have an issue with some customers who refuse to accept ICMP traffic to their mail servers. It seems that they have put Mordac, preventer of information services in charge of their firewall policy (http://en.wikipedia.org/wiki/List_of_minor_characters_in_Dilbert#Mordac). My mail logs are showing that customers who specifically disallow ICMP traffic have many "Connection Reset"

Hi, I get de following error messages in the logfile: var/log/tinc.ci1070300036.log:2011-08-16 14:12:54 tinc.ci1070300036[10834]: Possible node with same Name as us! Sleeping 10 seconds. I know that i don't have duplicate node names. But i see some strange node names: Al my node names start with ci but there is a node a did not create my self, and that is ca1070300036 How can i remove

Hi All, Sorry for disturbing you if the issues has been discussed earlier but I cannot find clear explanation of my problem. Tracing the tinc logs (a debug level) I have found that the MTU value of the connection is determined and chosen at the beginning of the tunnel setup. My question is following: is the MTU value renegotiated / rechecked after the tunnel is established? The question

Hello, I try to set up my Linux 2.4.x system to respond by "ICMP Destination Unreachable message" subtype 4 ("fragmentation needed and DF set") in order to support the Path MTU Discovery (RFC 1191) as a router. There is any /proc/xxx parameter to do this? Thanks Mugur _______________________________________________ LARTC mailing list LARTC@mailman.ds9a.nl

While working on SPTPS UDP relaying I realized that there is one issue I didn't account for, which is that the sending node only knows the PMTU to the first relay node. It doesn't know the PMTU of the entire relay path beyond the first hop, because the relay nodes don't provide their own PMTU information over the metaprotocol. Now, in the legacy protocol this is not really an issue,

Hi, I've got a relatively simple tinc setup. I've got two "servers" that are on the public internet that act as routers for three "clients" that are behind NATs. Those servers are called aaaaa and bbbbb the clients are xxxxx, yyyyy and zzzzz Unfortunatly the servers have problems accepting a connection from the clients syslog on aaaaa: Sep 29 18:28:58 schuerrer

Hi Guus and List, Since the CVE-2013-1428 was announced, I followed the recommendation to update my windows machines to tinc1.1pre7. I've had connectivity issues since upgrading. I've done some debugging but I can't figure out when or why its happening. All machines on the network are running Windows 7 or Windows 2008R2 Enterprise server and tinc 1.1pre7. I've got one master

Hi all, I have several locations, each connected by a Sonicwall VPN through PPPOE DSL, with Snom 360 phones. I've found that I have to tweak the Asterisk server MTU (inside one of the firewalls) to get everything to work "just right". Set the server MTU too low, and the Snom phones don't communicate correctly anymore. Too high and the phones work, but the server can't