Connecting to remote IPv6 addresses from Linux machine requires local scope id

[Dhiren Chandvania]

Title: IPv6 news - weekly summary

Configuration details:   Linux: ------ /sbin/ifconfig eth0      Link encap:Ethernet  HWaddr 00:30:6E:38:EA:EF           inet addr:10.212.86.40  Bcast:10.212.87.255  Mask:255.255.254.0           inet6 addr: fe80::230:6eff:fe38:eaef/64 Scope:Link           UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1           RX packets:141195117 errors:0 dropped:0 overruns:0 frame:0           TX packets:140958025 errors:0 dropped:0 overruns:0 carrier:0           collisions:0 txqueuelen:1000           RX bytes:54506828681 (50.7 GiB)  TX bytes:71024803048 (66.1 GiB)           Base address:0xa080 Memory:d0000000-d0020000   eth0:0    Link encap:Ethernet  HWaddr 00:30:6E:38:EA:EF           inet addr:192.168.1.223  Bcast:192.168.1.255  Mask:255.255.255.0           UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1           Base address:0xa080 Memory:d0000000-d0020000   lo        Link encap:Local Loopback           inet addr:127.0.0.1  Mask:255.0.0.0           inet6 addr: ::1/128 Scope:Host           UP LOOPBACK RUNNING  MTU:16436  Metric:1           RX packets:64880485 errors:0 dropped:0 overruns:0 frame:0           TX packets:64880485 errors:0 dropped:0 overruns:0 carrier:0           collisions:0 txqueuelen:0           RX bytes:352566279113 (328.3 GiB)  TX bytes:352566279113 (328.3 GiB)   sigfs     Link encap:IPv6-in-IPv4           inet6 addr: fe80::c0a8:1df/128 Scope:Link           UP POINTOPOINT RUNNING NOARP  MTU:1480  Metric:1           RX packets:0 errors:0 dropped:0 overruns:0 frame:0           TX packets:825 errors:0 dropped:0 overruns:0 carrier:0           collisions:0 txqueuelen:0           RX bytes:0 (0.0 b)  TX bytes:66116 (64.5 KiB)   Solaris: -------- lo0: flags=1000849<UP,LOOPBACK,RUNNING,MULTICAST,IPv4> mtu 8232 index 1         inet 127.0.0.1 netmask ff000000 hme0: flags=1000843<UP,BROADCAST,RUNNING,MULTICAST,IPv4> mtu 1500 index 2         inet 10.212.86.153 netmask fffffe00 broadcast 10.212.87.255         ether 0:3:ba:2:cc:ee hme0:1: flags=1000843<UP,BROADCAST,RUNNING,MULTICAST,IPv4> mtu 1500 index 2         inet 192.168.5.113 netmask ffffff00 broadcast 192.168.5.255 lo0: flags=2000849<UP,LOOPBACK,RUNNING,MULTICAST,IPv6> mtu 8252 index 1         inet6 ::1/128 hme0: flags=2000841<UP,RUNNING,MULTICAST,IPv6> mtu 1500 index 2         ether 0:3:ba:2:cc:ee         inet6 fe80::203:baff:fe02:ccee/10 ip.tun0: flags=2200851<UP,POINTOPOINT,RUNNING,MULTICAST,NONUD,IPv6> mtu 1480 index 3         inet tunnel src 192.168.5.113   tunnel dst 192.168.1.223         inet6 fe80::c0a8:571/10 --> fe80::c0a8:1df   Issues that I have:   I] All outbound traffic from a Linux machine needs scope id. Why? Tried the following sample for Solaris-Linux combination   Server on Solaris ------------------ bash-2.03# ./dtserver       Client on Linux (With scope id) ---------------- /var/tmp/test/dc/petes [EMAIL PROTECTED] petes]# ./dtclient  fe80::203:baff:fe02:ccee%2 Dhiren: Wed Jun 28 02:52:33 2006   The above client successfully connects to the Solaris server and retrieves the time from the server.   Client on Linux (Without scope id) ----------------   [EMAIL PROTECTED] petes]# ./dtclient  fe80::203:baff:fe02:ccee client error:: could not create connected socket socket     [II] Linux-Linux communication on IPv6 does not work even on specifying the scope id. This is messy and shouldn't it work ? Please provide your comments.   Server on Linux ----------------   [EMAIL PROTECTED] petes]# pwd /var/tmp/test/dc/petes [EMAIL PROTECTED] petes]# ./dtserver     Client on Linux ---------------- [EMAIL PROTECTED] petes]# pwd /var/tmp/test/dc/petes   ./dtclient  fe80::230:6eff:fe38:eaef%2   The client waits in connect call whereas the server does not get any request and is waiting in accept call    client: -------- socket(PF_INET6, SOCK_STREAM, IPPROTO_TCP) = 3 connect(3, {sa_family=AF_INET6, sin6_port=htons(3333), inet_pton(AF_INET6, "fe80::230:6eff:fe38:eaef", &sin6_addr), sin6_flowinfo=0, sin6_scope_id=if_nametoindex("eth0")}, 28   server ------- socket(PF_INET6, SOCK_STREAM, IPPROTO_TCP) = 3 bind(3, {sa_family=AF_INET6, sin6_port=htons(3333), inet_pton(AF_INET6, "::", &sin6_addr), sin6_flowinfo=0, sin6_scope_id=0}, 28) = 0 listen(3, 128)                          = 0 accept(3,     [EMAIL PROTECTED] /]# netstat -a | grep 3333 tcp        0      0 *:3333                      *:*                        LISTEN tcp        0      1 ::1:36188                   fe80::230:6eff:fe38:ea:3333 SYN_SENT       All the sample applications source code is attached:   Thanks in advance.   Dhiren