-=| gregor herrmann, 28.09.2011 19:31:45 +0200 |=- > and then nothing until (my telnet attempts before): > > 2011/09/28-18:17:45 CONNECT TCP Peer: "::1:32798" Local: "::1:4949" > Invalid netblock: 127.255.255.255-0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.1 at > /usr/share/perl5/Net/Server.pm line 849 > 2011/09/28-18:25:32 CONNECT TCP Peer: > "2001:15c0:66bc:0:211:11ff:fe92:3e20:33975" Local: > "2001:15c0:66bc:0:211:11ff:fe92:3e20:4949"
Could this be related to the way connections are controlled in munin-node.conf? I have it via allow ^127\.0\.0\.1$ and allow ^$munin_server$ Do you use cidr_allow/cidr_deny? > - Ansgar mentioned sys.net.ipv6.bindv6only on IRC. > > root@belanna:~# sysctl net.ipv6.bindv6only > net.ipv6.bindv6only = 1 > > Oh, and setting it to 0 changes something: > > root@belanna:~# telnet ::1 4949 > Trying ::1... > Connected to ::1. > Escape character is '^]'. > Connection closed by foreign host. > > root@belanna:~# telnet 127.0.0.1 4949 > Trying 127.0.0.1... > Connected to 127.0.0.1. > Escape character is '^]'. > # munin node at belanna.comodo.priv.at > Connection closed by foreign host. > > So, with net.ipv6.bindv6only = 1 there's no ipv4 connection; with = 0 > ipv4 works. Good catch. It seems I have 'net.ipv6.bindv6only = 0' in /etc/sysctl.d/bindv6only.conf. Not sure where that came from. It is quite possible that I have set the value at some point in the past. Here's some interesting prose from that file: # This sysctl sets the default value of the IPV6_V6ONLY socket # option. # # When disabled, IPv6 sockets will also be able to send and receive # IPv4 # traffic with addresses in the form ::ffff:192.0.2.1 and daemons # listening # on IPv6 sockets will also accept IPv4 connections. # # When IPV6_V6ONLY is enabled, daemons interested in both IPv4 and # IPv6 # connections must open two listening sockets. # This is the default behaviour of all modern operating systems. Yeah, right :) But the advise to open two sockets may still be useful. > And ipv6 works connection-wise in both cases but doesn't > generate a prompt in my telnet attempt?! ipv6 is weird, you say? :))
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