netdev
[Top] [All Lists]

Proble with sit0 (sit.c)

To: Linux net <netdev@xxxxxxxxxxx>
Subject: Proble with sit0 (sit.c)
From: Gilles Diribarne <gilles.diribarne@xxxxxxxxxxxxx>
Date: Fri, 20 Apr 2001 11:46:21 +0200
Organization: Alcatel CRC
Sender: owner-netdev@xxxxxxxxxxx
Hi,

I've a TCP bug with sit0. I have two DS IPv4/IPV6 node.
I set up a route on each node for the IPv4-compat V6 address. The routing table is below
We have the same problem with 2002:/16 address.

Kernel IPv6 routing table
Destination                                 Next Hop                                Flags Metric Ref    Use Iface
::1/128                                     ::                                      U     0      0        0 lo
::127.0.0.1/128                             ::                                      U     0      0        0 lo
::192.168.52.2/128                          ::                                      U     0      0        0 lo
::/96                                       ::                                      U     256    0        0 sit0
2002:c0a8:3402:2::2/128                     ::                                      U     0      0        0 lo
2002:c0a8:3402:2:201:2ff:feb1:4fb1/128      ::                                      U     0      0        0 lo
2002:c0a8:3402:2::/64                       ::                                      UA    256    44       0 eth0
2002::/16                                   ::                                      U     1      0        0 sit0
fe80::c0a8:1502/128                         ::                                      U     0      0        0 lo
fe80::c0a8:3402/128                         ::                                      U     0      0        0 lo
fe80::201:2ff:feac:cd72/128                 ::                                      U     0      0        0 lo
fe80::201:2ff:feb1:4fb1/128                 ::                                      U     0      0        0 lo
fe80::/10                                   ::                                      UA    256    0        0 eth0
fe80::/10                                   ::                                      UA    256    0        0 eth1
fe80::/10                                   ::                                      UA    256    0        0 sit1
ff02::1/128                                 ff02::1                                 UAC   0      1        1 eth0
ff00::/8                                    ::                                      UA    256    0        0 eth0
ff00::/8                                    ::                                      UA    256    0        0 eth1
ff00::/8                                    ::                                      UA    256    0        0 sit1
::/0                                        ::                                      UDA   256    0        0 eth1

This route has been set up
route -Ainet6 ::/96 sit0

After, I make a ping
# ping6 ::192.168.46.4
PING ::192.168.46.4 (::192.168.46.4): 56 data bytes
64 bytes from ::192.168.46.4: icmp_seq=0 ttl=64 time=0.745 ms
64 bytes from ::192.168.46.4: icmp_seq=1 ttl=64 time=0.481 ms
64 bytes from ::192.168.46.4: icmp_seq=2 ttl=64 time=0.473 ms
64 bytes from ::192.168.46.4: icmp_seq=3 ttl=64 time=0.434 ms
64 bytes from ::192.168.46.4: icmp_seq=4 ttl=64 time=0.444 ms
64 bytes from ::192.168.46.4: icmp_seq=5 ttl=64 time=0.415 ms
64 bytes from ::192.168.46.4: icmp_seq=6 ttl=64 time=0.438 ms
It runs...

But, when I want to make a TCP connection, it fails
Here is the trace. It was a BGP connection made with Zebra.

Frame 4 (114 on wire, 114 captured)
    Arrival Time: Apr 20, 2001 09:48:38.2649
    Time delta from previous packet: 9.768477 seconds
    Time relative to first packet: 29.788480 seconds
    Frame Number: 4
    Packet Length: 114 bytes
    Capture Length: 114 bytes
Ethernet II
    Destination: 00:01:02:ab:e3:cd (BBN_ab:e3:cd)
    Source: 00:01:02:ac:cd:72 (BBN_ac:cd:72)
    Type: IP (0x0800)
Internet Protocol
    Version: 4
    Header length: 20 bytes
    Differentiated Services Field: 0x00 (DSCP 0x00: Default; ECN: 0x00)
        0000 00.. = Differentiated Services Codepoint: Default (0x00)
        .... ..0. = ECN-Capable Transport (ECT): 0
        .... ...0 = ECN-CE: 0
    Total Length: 100
    Identification: 0x0000
    Flags: 0x04
        .1.. = Don't fragment: Set
        ..0. = More fragments: Not set
    Fragment offset: 0
    Time to live: 64
    Protocol: IPv6 (0x29)
    Header checksum: 0x571a (correct)
    Source: 192.168.52.2 (192.168.52.2)
    Destination: 192.168.46.4 (192.168.46.4)
Internet Protocol Version 6
    Version: 6
    Traffic class: 0x00
    Flowlabel: 0x00000
    Payload length: 40
    Next header: TCP (0x06)
    Hop limit: 64
    Source address: ::192.168.52.2
    Destination address: ::192.168.46.4
Transmission Control Protocol, Src Port: 1055 (1055), Dst Port: bgp (179), Seq: 2091346880, Ack: 0
    Source port: 1055 (1055)
    Destination port: bgp (179)
    Sequence number: 2091346880
    Header length: 40 bytes
    Flags: 0x0002 (SYN)
        0... .... = Congestion Window Reduced (CWR): Not set
        .0.. .... = ECN-Echo: Not set
        ..0. .... = Urgent: Not set
        ...0 .... = Acknowledgment: Not set
        .... 0... = Push: Not set
        .... .0.. = Reset: Not set
        .... ..1. = Syn: Set
        .... ...0 = Fin: Not set
    Window size: 5680
    Checksum: 0xf17b (correct)
    Options: (20 bytes)
        Maximum segment size: 1420 bytes
        SACK permitted
        Time stamp: tsval 5730203, tsecr 0
        NOP
        Window scale: 0 bytes

Frame 5 (106 on wire, 106 captured)
    Arrival Time: Apr 20, 2001 09:48:38.2654
    Time delta from previous packet: 0.000442 seconds
    Time relative to first packet: 29.788922 seconds
    Frame Number: 5
    Packet Length: 106 bytes
    Capture Length: 106 bytes
Ethernet II
    Destination: 00:01:02:ac:cd:72 (BBN_ac:cd:72)
    Source: 00:01:02:ab:e3:cd (BBN_ab:e3:cd)
    Type: IP (0x0800)
Internet Protocol
    Version: 4
    Header length: 20 bytes
    Differentiated Services Field: 0x00 (DSCP 0x00: Default; ECN: 0x00)
        0000 00.. = Differentiated Services Codepoint: Default (0x00)
        .... ..0. = ECN-Capable Transport (ECT): 0
        .... ...0 = ECN-CE: 0
    Total Length: 92
    Identification: 0x0000
    Flags: 0x04
        .1.. = Don't fragment: Set
        ..0. = More fragments: Not set
    Fragment offset: 0
    Time to live: 62
    Protocol: IPv6 (0x29)
    Header checksum: 0x5922 (correct)
    Source: 192.168.46.4 (192.168.46.4)
    Destination: 192.168.52.2 (192.168.52.2)
Internet Protocol Version 6
    Version: 6
    Traffic class: 0x00
    Flowlabel: 0x00000
    Payload length: 32
    Next header: TCP (0x06)
    Hop limit: 64
    Source address: ::192.168.46.4
    Destination address: ::192.168.52.2
Transmission Control Protocol, Src Port: bgp (179), Dst Port: 1055 (1055), Seq: 2250769922, Ack: 2091346881
    Source port: bgp (179)
    Destination port: 1055 (1055)
    Sequence number: 2250769922
    Acknowledgement number: 2091346881
    Header length: 32 bytes
    Flags: 0x0012 (SYN, ACK)
        0... .... = Congestion Window Reduced (CWR): Not set
        .0.. .... = ECN-Echo: Not set
        ..0. .... = Urgent: Not set
        ...1 .... = Acknowledgment: Set
        .... 0... = Push: Not set
        .... .0.. = Reset: Not set
        .... ..1. = Syn: Set
        .... ...0 = Fin: Not set
    Window size: 5680
    Checksum: 0xfc43 (correct)
    Options: (12 bytes)
        Maximum segment size: 1420 bytes
        NOP
        NOP
        SACK permitted
        NOP
        Window scale: 0 bytes

Frame 6 (94 on wire, 94 captured)
    Arrival Time: Apr 20, 2001 09:48:38.2654
    Time delta from previous packet: 0.000034 seconds
    Time relative to first packet: 29.788956 seconds
    Frame Number: 6
    Packet Length: 94 bytes
    Capture Length: 94 bytes
Ethernet II
    Destination: 00:01:02:ab:e3:cd (BBN_ab:e3:cd)
    Source: 00:01:02:ac:cd:72 (BBN_ac:cd:72)
    Type: IP (0x0800)
Internet Protocol
    Version: 4
    Header length: 20 bytes
    Differentiated Services Field: 0x00 (DSCP 0x00: Default; ECN: 0x00)
        0000 00.. = Differentiated Services Codepoint: Default (0x00)
        .... ..0. = ECN-Capable Transport (ECT): 0
        .... ...0 = ECN-CE: 0
    Total Length: 80
    Identification: 0x0000
    Flags: 0x04
        .1.. = Don't fragment: Set
        ..0. = More fragments: Not set
    Fragment offset: 0
    Time to live: 64
    Protocol: IPv6 (0x29)
    Header checksum: 0x572e (correct)
    Source: 192.168.52.2 (192.168.52.2)
    Destination: 192.168.46.4 (192.168.46.4)
Internet Protocol Version 6
    Version: 6
    Traffic class: 0x00
    Flowlabel: 0x00000
    Payload length: 20
    Next header: TCP (0x06)
    Hop limit: 64
    Source address: ::192.168.52.2
    Destination address: ::192.168.46.4
Transmission Control Protocol, Src Port: 1055 (1055), Dst Port: bgp (179), Seq: 2091346881, Ack: 0
    Source port: 1055 (1055)
    Destination port: bgp (179)
    Sequence number: 2091346881
    Header length: 20 bytes
    Flags: 0x0004 (RST)
        0... .... = Congestion Window Reduced (CWR): Not set
        .0.. .... = ECN-Echo: Not set
        ..0. .... = Urgent: Not set
        ...0 .... = Acknowledgment: Not set
        .... 0... = Push: Not set
        .... .1.. = Reset: Set
        .... ..0. = Syn: Not set
        .... ...0 = Fin: Not set
    Window size: 0
    Checksum: 0xdf4e (correct)

Can someone help us?
Is it a sit0 bug?

Regards,
Gilles

-- 
 Gilles Diribarne
 Alcatel Research & Innovation
 Gilles.Diribarne@xxxxxxxxxx
 Tel: +33 (0)1 69 63 46 45      Fax: +33 (0)1 69 63 11 69
 
<Prev in Thread] Current Thread [Next in Thread>
  • Proble with sit0 (sit.c), Gilles Diribarne <=