[Xorp-users] IPv6 intermittent connectivity

Hansi hantongs at gmail.com
Tue Nov 6 22:13:43 PST 2007


 Hello Pavlin,

            +----------+                     +----------+
            | PC1      +---------------------+          |
            |          |                sk0  | Router 1 |
            +----------+2001:ec1:4001:10af::1+-----+----+

                                                   | vr0  2001:ec0:4000:beef::1
                                                   |
                                                   |
                                                   |
                                                   |
                                                   |
                                                   | vr0  2001:ec0:4000:beef::2
            +----------+                     +-----+----+
            | PC2      +---------------------+          |
            |          |                sk0  | Router 2 |
            +----------+2001:ec2:4002:fa11::1+----------+

PC1 IPv6 address: 2001:ec1:4001:10af:219:5bff:fe2f:1468
PC2 IPv6 address: 2001:ec2:4002:fa11:200:24ff:fec4:3235

Manual Configuration of Static Routes: (no XORP)
Router 1

$ netstat -nra | more
Routing tables


Internet6:
Destination                       Gateway                       Flags
Netif
 Expire
::/96                             ::1                           UGRS
lo0
::1                               ::1                           UHL
lo0
::ffff:0.0.0.0/96                 ::1                           UGRS
lo0
2001:ec0:4000:beef::/64           link#2                        UC
vr0
2001:ec0:4000:beef::1             00:13:d4:d8:68:08             UHL
lo0
2001:ec0:4000:beef::2             00:15:f2:3d:ac:91             UHLW
vr0
2001:ec1:4001:10af::/64           link#1                        UC
sk0
2001:ec1:4001:10af::1             00:19:5b:85:cf:c7             UHL
lo0
2001:ec1:4001:10af:219:5bff:fe2f:1468 00:19:5b:2f:14:68
UHLW
sk0
2001:ec2:4002:fa11::/64           2001:ec0:4000:beef::2         UGS
vr0

Router 2

$ netstat -nra | more
Internet6:
Destination                       Gateway                       Flags
Netif
 Expire
::/96                             ::1                           UGRS
lo0
::1                               ::1                           UHL
lo0
::ffff:0.0.0.0/96                 ::1                           UGRS
lo0
2001:ec0:4000:beef::/64           link#2                        UC
vr0
2001:ec0:4000:beef::1             00:13:d4:d8:68:08             UHLW
vr0
2001:ec0:4000:beef::2             00:15:f2:3d:ac:91             UHL
lo0
2001:ec1:4001:10af::/64           2001:ec0:4000:beef::1         UGS
vr0
2001:ec2:4002:fa11::/64           link#1                        UC
sk0
2001:ec2:4002:fa11::1             00:19:5b:2f:14:6a             UHL
lo0
2001:ec2:4002:fa11:200:24ff:fec4:3235 00:00:24:c4:32:35
UHLW
sk0

Here are the ping results from pc1 to pc2 and vice versa:

hansi at hansi-desktop:~$ ping6 2001:ec2:4002:fa11:200:24ff:fec4:3235
PING
2001:ec2:4002:fa11:200:24ff:fec4:3235(2001:ec2:4002:fa11:200:24ff:fec4:3235)
56 data bytes
64 bytes from 2001:ec2:4002:fa11:200:24ff:fec4:3235: icmp_seq=1 ttl=62 time=
0.650 ms
64 bytes from 2001:ec2:4002:fa11:200:24ff:fec4:3235: icmp_seq=2 ttl=62 time=
0.631 ms
64 bytes from 2001:ec2:4002:fa11:200:24ff:fec4:3235: icmp_seq=3 ttl=62 time=
0.662 ms
64 bytes from 2001:ec2:4002:fa11:200:24ff:fec4:3235: icmp_seq=4 ttl=62 time=
0.696 ms
64 bytes from 2001:ec2:4002:fa11:200:24ff:fec4:3235: icmp_seq=5 ttl=62 time=
0.735 ms
64 bytes from 2001:ec2:4002:fa11:200:24ff:fec4:3235: icmp_seq=6 ttl=62 time=
0.651 ms
64 bytes from 2001:ec2:4002:fa11:200:24ff:fec4:3235: icmp_seq=7 ttl=62 time=
0.587 ms
64 bytes from 2001:ec2:4002:fa11:200:24ff:fec4:3235: icmp_seq=8 ttl=62 time=
0.719 ms
64 bytes from 2001:ec2:4002:fa11:200:24ff:fec4:3235: icmp_seq=9 ttl=62 time=
0.670 ms
64 bytes from 2001:ec2:4002:fa11:200:24ff:fec4:3235: icmp_seq=10 ttl=62
time=0.706 ms


hansi at hansi-desktop:~$ ping6 2001:ec1:4001:10af:219:5bff:fe2f:1468
PING6(56=40+8+8 bytes) 2001:ec2:4002:fa11:200:24ff:fec4:3235 -->
2001:ec1:4001:10af:219:5bff:fe2f:1468
16 bytes from 2001:ec1:4001:10af:219:5bff:fe2f:1468, icmp_seq=0 hlim=62
time=1.117 ms
16 bytes from 2001:ec1:4001:10af:219:5bff:fe2f:1468, icmp_seq=1 hlim=62
time=1.041 ms
16 bytes from 2001:ec1:4001:10af:219:5bff:fe2f:1468, icmp_seq=2 hlim=62
time=0.987 ms
16 bytes from 2001:ec1:4001:10af:219:5bff:fe2f:1468, icmp_seq=3 hlim=62
time=0.927 ms
16 bytes from 2001:ec1:4001:10af:219:5bff:fe2f:1468, icmp_seq=4 hlim=62
time=0.990 ms
16 bytes from 2001:ec1:4001:10af:219:5bff:fe2f:1468, icmp_seq=5 hlim=62
time=0.928 ms
16 bytes from 2001:ec1:4001:10af:219:5bff:fe2f:1468, icmp_seq=6 hlim=62
time=1.036 ms
16 bytes from 2001:ec1:4001:10af:219:5bff:fe2f:1468, icmp_seq=7 hlim=62
time=1.025 ms
16 bytes from 2001:ec1:4001:10af:219:5bff:fe2f:1468, icmp_seq=8 hlim=62
time=1.045 ms
16 bytes from 2001:ec1:4001:10af:219:5bff:fe2f:1468, icmp_seq=9 hlim=62
time=0.946 ms
16 bytes from 2001:ec1:4001:10af:219:5bff:fe2f:1468, icmp_seq=10 hlim=62
time=0.973 ms


Configuration of Static Routes through XORP

Router 1

$ sudo route -n monitor
Password:

got message of size 328 on Tue Nov  6 23:24:55 2007
RTM_ADD: Add Route: len 328, pid: 0, seq 0, errno 0,
flags:<UP,HOST,DONE,LLINFO,WASCLONED>
locks:  inits:
sockaddrs: <DST,GATEWAY,IFP,IFA>
 2001:ec0:4000:beef::2  vr0:0.13.d4.d8.68.8 fe80::213:d4ff:fed8:6808%vr0

got message of size 304 on Tue Nov  6 23:24:55 2007
RTM_ADD: Add Route: len 304, pid: 4927, seq 131072, errno 0,
flags:<UP,GATEWAY,DONE,PROTO1>
locks:  inits:
sockaddrs: <DST,GATEWAY,NETMASK,IFP>
 2001:ec2:4002:fa11:: 2001:ec0:4000:beef::2 ffff:ffff:ffff:ffff::

$ netstat -nra | more

Internet6:
Destination                       Gateway                       Flags
Netif
 Expire
::/96                             ::1                           UGRS
lo0
::1                               ::1                           UHL
lo0
::ffff:0.0.0.0/96                 ::1                           UGRS
lo0
2001:ec0:4000:beef::/64           link#2                        UC
vr0
2001:ec0:4000:beef::1             00:13:d4:d8:68:08             UHL
lo0
2001:ec0:4000:beef::2             link#2                        UHLW
vr0
2001:ec0:4000:beef::2             00:15:f2:3d:ac:91             UHLW
vr0
2001:ec1:4001:10af::/64           link#1                        UC
sk0
2001:ec1:4001:10af::1             00:19:5b:85:cf:c7             UHL
lo0
2001:ec1:4001:10af:219:5bff:fe2f:1468 00:19:5b:2f:14:68
UHLW
sk0
2001:ec1:4001:10af::/64/64        2001:ec0:4000:beef::2         UG1
vr0
fe80::/10                         ::1                           UGRS
lo0
fe80::%sk0/64                     link#1                        UC

Router 2

$ sudo route -n monitor
Password:

got message of size 328 on Wed Nov  7 03:23:40 2007
RTM_ADD: Add Route: len 328, pid: 0, seq 0, errno 0,
flags:<UP,HOST,DONE,LLINFO,WASCLONED>
locks:  inits:
sockaddrs: <DST,GATEWAY,IFP,IFA>
 2001:ec0:4000:beef::1  vr0:0.15.f2.3d.ac.91 fe80::215:f2ff:fe3d:ac91%vr0

got message of size 304 on Wed Nov  7 03:23:40 2007
RTM_ADD: Add Route: len 304, pid: 4593, seq 131072, errno 0,
flags:<UP,GATEWAY,DONE,PROTO1>
locks:  inits:
sockaddrs: <DST,GATEWAY,NETMASK,IFP>
 2001:ec1:4001:10af:: 2001:ec0:4000:beef::1 ffff:ffff:ffff:ffff:: vr0

$ netstat -nra | more
Internet6:
Destination                       Gateway                       Flags
Netif
 Expire
::/96                             ::1                           UGRS
lo0
::1                               ::1                           UHL
lo0
::ffff:0.0.0.0/96                 ::1                           UGRS
lo0
2001:ec0:4000:beef::/64           link#2                        UC
vr0
2001:ec0:4000:beef::1             link#2                        UHLW
vr0
2001:ec0:4000:beef::1             00:13:d4:d8:68:08             UHLW
vr0
2001:ec0:4000:beef::2             00:15:f2:3d:ac:91             UHL
lo0
2001:ec0:4000:beef::/64/64        2001:ec0:4000:beef::1         UG1
vr0
2001:ec2:4002:fa11::/64           link#1                        UC
sk0
2001:ec2:4002:fa11::1             00:19:5b:2f:14:6a             UHL
lo0
2001:ec2:4002:fa11:200:24ff:fec4:3235 00:00:24:c4:32:35             UHLW


Here are the ping results from pc1 to pc2 and vice versa:

hansi at hansi-desktop:~$ ping6 2001:ec2:4002:fa11:200:24ff:fec4:3235
PING
2001:ec2:4002:fa11:200:24ff:fec4:3235(2001:ec2:4002:fa11:200:24ff:fec4:3235)
56 data bytes

64 bytes from 2001:ec2:4002:fa11:200:24ff:fec4:3235: icmp_seq=16 ttl=62
time=0.834 ms
64 bytes from 2001:ec2:4002:fa11:200:24ff:fec4:3235: icmp_seq=17 ttl=62
time=0.614 ms
64 bytes from 2001:ec2:4002:fa11:200:24ff:fec4:3235: icmp_seq=18 ttl=62
time=0.753 ms
64 bytes from 2001:ec2:4002:fa11:200:24ff:fec4:3235: icmp_seq=19 ttl=62
time=0.695 ms
64 bytes from 2001:ec2:4002:fa11:200:24ff:fec4:3235: icmp_seq=20 ttl=62
time=0.736 ms
64 bytes from 2001:ec2:4002:fa11:200:24ff:fec4:3235: icmp_seq=21 ttl=62
time=0.567 ms
64 bytes from 2001:ec2:4002:fa11:200:24ff:fec4:3235: icmp_seq=22 ttl=62
time=0.716 ms
64 bytes from 2001:ec2:4002:fa11:200:24ff:fec4:3235: icmp_seq=23 ttl=62
time=0.655 ms

$ ping6 2001:ec1:4001:10af:219:5bff:fe2f:1468
PING6(56=40+8+8 bytes) 2001:ec2:4002:fa11:200:24ff:fec4:3235 -->
2001:ec1:4001:10af:219:5bff:fe2f:1468
^C
--- 2001:ec1:4001:10af:219:5bff:fe2f:1468 ping6 statistics ---
179 packets transmitted, 0 packets received, 100.0% packet loss

Taking a closer look on the ping results would show that there are missing
icmp packets from sequence 1 to 15 while pinging from pc2 to pc1 translates
to a 100% packet loss.

My purpose is to add route 2001:ec2:4002:fa11::/64 through next hop address
2001:ec0:4000:beef::2 on router 1 as well as add 2001:ec1:4001:10af::/64
through next hop address 2001:ec0:4000:beef::1 on router 2.

Attached is the xorp config file. I didnt bother pasting it here since
On 11/6/07, Pavlin Radoslavov <pavlin at icir.org> wrote:
>
> > > Looking closely on the routing table produced by netstat would show:
> > >
> > > Manually added routes:
> > >
> > > 2001:ec2:4002:fa11::/64           2001:ec0:4000:beef::2
> > > UGS         vr0
> > >
> > > Routes added by xorp:
> > >
> > > 2001:ec1:4001:10af::/64/64        2001:ec0:4000:beef::2
> > > UG1         vr0
>
> Interesting. Initially my first impression was that the double
> /64/64 is a typo, but the raw "netstat" output also contains it.
> Could you send the your XORP configuration, as well as the output of
> running ping with XORP and with manual static routes.
> The routes themselves are different (4002 vs 4001) which is also

add.


Probably a wrong destination network added to the routing table?

FYI, the "S" vs "1" flag (i.e., "UGS" vs "UG1") is normal.
>
> Also, could you run "route -n monitor" before starting XORP, and
> send the output of the messages until after XORP is started.
>
> Thanks,
> Pavlin
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://mailman.ICSI.Berkeley.EDU/pipermail/xorp-users/attachments/20071107/d924d8e8/attachment-0001.html 
-------------- next part --------------
An embedded and charset-unspecified text was scrubbed...
Name: xorpcfg.txt
Url: http://mailman.ICSI.Berkeley.EDU/pipermail/xorp-users/attachments/20071107/d924d8e8/attachment-0001.txt 


More information about the Xorp-users mailing list