Wired behaviour with IPv6 over PPP

DISCUSSION Matthias Cramer 5 participants 10 messages May 21, 2008 – May 28, 2008

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Matthias Cramer

author

2008-05-21 13:03 UTC #0 lore raw

Hi All

I have a very wired behaviour when doing IPv6 over PPPoE.

The situation:

A linux box connected to a DSL Modem, on the other side is a Cisco LNS which terminates the PPP session (actually L2TP). I have control over both ends.

When I have net.ipv6.conf.all.forwarding set to 0 then the ppp Interface gets a IPv6 address from the Cisco via IP6CP. When I have net.ipv6.conf.all.forwarding set to 1 them the ppp Interface does not get an address, it has only a normal link local address.

When I start the ppp session with forwarding set to 0 I can ping out and there exists a default route to ppp0 , then I switch forwarding to 1 the default route disappears and therefore routing does not work any longer.

Is this a known behaviour ?

Or am I doing something the wrong way ?

Kernel version is 2.6.25

Best regards

Matthias

Signature · 5 lines

Matthias Cramer / mc322-ripe   System & Network Manager
Interway Communication GmbH    Phone +41 43 500 1111
Josefstrasse 225               Fax   +41 44 271 3535
CH-8005 Zürich                 http://www.interway.ch/
GnuPG 1024D/2D208250 = DBC6 65B6 7083 1029 781E  3959 B62F DF1C 2D20 8250

Andrew Morton

2008-05-22 08:50 UTC #1 lore raw

Quoted 12 lines · On Wed, 21 May 2008 14:56:43 +0200 Matthias Cramer…

Hi All
I have a very wired behaviour when doing IPv6 over PPPoE.
The situation:
A linux box connected to a DSL Modem, on the other side is a Cisco LNS which terminates the PPP session (actually L2TP). I have control over both ends.
When I have net.ipv6.conf.all.forwarding set to 0 then the ppp Interface gets a IPv6 address from the Cisco via IP6CP. When I have net.ipv6.conf.all.forwarding set to 1 them the ppp Interface does not get an address, it has only a normal link local address.

Quoted 9 lines

When I start the ppp session with forwarding set to 0 I can ping out and there exists a default route to ppp0 , then I switch forwarding to 1 the default route disappears and therefore routing does not work any longer.
Is this a known behaviour ?
Or am I doing something the wrong way ?
Kernel version is 2.6.25

(cc netdev)

James Chapman

2008-05-22 09:55 UTC #2 lore raw

Quoted 6 lines · Andrew Morton

Quoted 4 lines · On Wed, 21 May 2008 14:56:43 +0200 Matthias Cramer…
Hi All
I have a very wired behaviour when doing IPv6 over PPPoE.

Quoted 7 lines

Quoted 7 lines
The situation:
A linux box connected to a DSL Modem, on the other side is a Cisco LNS which terminates the PPP session (actually L2TP). I have control over both ends.
When I have net.ipv6.conf.all.forwarding set to 0 then the ppp Interface gets a IPv6 address from the Cisco via IP6CP. When I have net.ipv6.conf.all.forwarding set to 1 them the ppp Interface does not get an address, it has only a normal link local address.

What do you mean by normal link local address?

Quoted 2 lines

Quoted 2 lines
When I start the ppp session with forwarding set to 0 I can ping out and there exists a default route to ppp0 , then I switch forwarding to 1 the default route disappears and therefore routing does not work any longer.

Did this work with previous kernel versions?

Does pppd log any errors?

Quoted 6 lines

Quoted 6 lines
Is this a known behaviour ?
Or am I doing something the wrong way ?
Kernel version is 2.6.25

Signature · 4 lines

James Chapman
Katalix Systems Ltd
http://www.katalix.com
Catalysts for your Embedded Linux software development

Matthias Cramer

author

2008-05-22 19:05 UTC #3 lore raw

Quoted 11 lines · James Chapman

Quoted 10 lines · Andrew Morton
Quoted 8 lines · On Wed, 21 May 2008 14:56:43 +0200 Matthias Cramer…
I have a very wired behaviour when doing IPv6 over PPPoE.
The situation:
A linux box connected to a DSL Modem, on the other side is a Cisco LNS which terminates the PPP session (actually L2TP).
I have control over both ends.

Quoted 7 lines

Quoted 5 lines
Quoted 5 lines
When I have net.ipv6.conf.all.forwarding set to 0 then the ppp Interface gets a IPv6 address from the Cisco via IP6CP. When I have net.ipv6.conf.all.forwarding set to 1 them the ppp Interface does not get an address, it has only a normal link local address.
What do you mean by normal link local address?

a fe80:: address, which every IPv6 enabled Interface has...

Quoted 7 lines

Quoted 5 lines
Quoted 5 lines
When I start the ppp session with forwarding set to 0 I can ping out and there exists a default route to ppp0 , then I switch forwarding to 1 the default route disappears and therefore routing does not work any longer.
Did this work with previous kernel versions?

No, in my opinion it never worked. But I thought that pppd does it wrong because id never got an IPv6 address. But I had always forwarding enabled. Now in this case i started pppd without forwarding enabled and got an address.

Quoted 2 lines

Does pppd log any errors?

No, no errors

Signature · 4 lines

Matthias Cramer                System & Network Manager
Interway Communication GmbH    Phone +41 43 500 1111
Josefstrasse 225               Fax   +41 44 271 3535
CH-8005 Zuerich                http://www.interway.ch/

James Chapman

2008-05-23 10:46 UTC #4 lore raw

Quoted 11 lines · Matthias Cramer

Quoted 1 line · James Chapman
Did this work with previous kernel versions?
No, in my opinion it never worked. But I thought that pppd does it wrong because id never got an IPv6 address. But I had always forwarding enabled. Now in this case i started pppd without forwarding enabled and got an address.
Quoted 1 line
Does pppd log any errors?
No, no errors

Could you post a pppd debug log showing the ppp protocol exchange with the peer in the failing case? It might give some clues.

Signature · 4 lines

James Chapman
Katalix Systems Ltd
http://www.katalix.com
Catalysts for your Embedded Linux software development

Matthias Cramer

author

2008-05-23 19:51 UTC #5 lore raw

Hi James

Quoted 9 lines · James Chapman

Quoted 8 lines · Matthias Cramer
Quoted 1 line · James Chapman
Did this work with previous kernel versions?
No, in my opinion it never worked. But I thought that pppd does it wrong because id never got an IPv6 address. But I had always forwarding enabled. Now in this case i started pppd without forwarding enabled and got an address.

Quoted 6 lines

Quoted 3 lines
Quoted 1 line
Does pppd log any errors?
No, no errors
Could you post a pppd debug log showing the ppp protocol exchange with the peer in the failing case? It might give some clues.

Here the logs ... First with forwarding enabled and second with disabled ...

net.ipv6.conf.all.forwarding=1

May 23 21:38:49 alix-tst pppd[29490]: Plugin rp-pppoe.so loaded.
May 23 21:38:49 alix-tst pppd[29491]: pppd 2.4.4 started by root, uid 0
May 23 21:38:49 alix-tst pppd[29491]: PADS: Service-Name: ''
May 23 21:38:49 alix-tst pppd[29491]: PPP session is 675
May 23 21:38:49 alix-tst pppd[29491]: using channel 10
May 23 21:38:49 alix-tst pppd[29491]: Using interface ppp0
May 23 21:38:49 alix-tst pppd[29491]: Connect: ppp0 <--> eth0
May 23 21:38:49 alix-tst pppd[29491]: sent [LCP ConfReq id=0x1 <mru 1492> <magic 0xadacf61b>]
May 23 21:38:49 alix-tst pppd[29491]: rcvd [LCP ConfReq id=0xc8 <mru 1492> <auth chap MD5> <magic 0x6887033f>]
May 23 21:38:49 alix-tst pppd[29491]: sent [LCP ConfAck id=0xc8 <mru 1492> <auth chap MD5> <magic 0x6887033f>]
May 23 21:38:49 alix-tst pppd[29491]: rcvd [LCP ConfAck id=0x1 <mru 1492> <magic 0xadacf61b>]
May 23 21:38:49 alix-tst pppd[29491]: sent [LCP EchoReq id=0x0 magic=0xadacf61b]
May 23 21:38:49 alix-tst pppd[29491]: rcvd [CHAP Challenge id=0xa7 <c3ca04555d0b05c824913a485207145a>, name = "ipc-zhh790-r-br-03"]
May 23 21:38:49 alix-tst pppd[29491]: sent [CHAP Response id=0xa7 <4e5f2e265676afd4426f96a4f3d69d98>, name = "dol/[email protected]"]
May 23 21:38:49 alix-tst pppd[29491]: rcvd [LCP EchoRep id=0x0 magic=0x6887033f]
May 23 21:38:50 alix-tst pppd[29491]: rcvd [LCP ConfReq id=0x1 <auth pap> <magic 0x81e3711d>]
May 23 21:38:50 alix-tst pppd[29491]: sent [LCP ConfReq id=0x2 <mru 1492> <magic 0xe78877a6>]
May 23 21:38:50 alix-tst pppd[29491]: sent [LCP ConfAck id=0x1 <auth pap> <magic 0x81e3711d>]
May 23 21:38:50 alix-tst pppd[29491]: rcvd [LCP ConfAck id=0x2 <mru 1492> <magic 0xe78877a6>]
May 23 21:38:50 alix-tst pppd[29491]: sent [LCP EchoReq id=0x0 magic=0xe78877a6]
May 23 21:38:50 alix-tst pppd[29491]: sent [PAP AuthReq id=0x1 user="dol/[email protected]" password=<hidden>]
May 23 21:38:50 alix-tst pppd[29491]: rcvd [LCP ConfReq id=0x1 <mru 1492> <auth chap MD5> <magic 0x708ab66f>]
May 23 21:38:50 alix-tst pppd[29491]: sent [LCP ConfReq id=0x3 <mru 1492> <magic 0xade5da06>]
May 23 21:38:50 alix-tst pppd[29491]: sent [LCP ConfAck id=0x1 <mru 1492> <auth chap MD5> <magic 0x708ab66f>]
May 23 21:38:50 alix-tst pppd[29491]: rcvd [LCP ConfAck id=0x3 <mru 1492> <magic 0xade5da06>]
May 23 21:38:50 alix-tst pppd[29491]: sent [LCP EchoReq id=0x0 magic=0xade5da06]
May 23 21:38:50 alix-tst pppd[29491]: rcvd [CHAP Challenge id=0x1 <5de7704ca9b8440a185c21438e465653>, name = "brain.glb"]
May 23 21:38:50 alix-tst pppd[29491]: sent [CHAP Response id=0x1 <7cca580881d4ca01c3f191382ec97df2>, name = "dol/[email protected]"]
May 23 21:38:50 alix-tst pppd[29491]: rcvd [LCP EchoRep id=0x0 magic=0x708ab66f]
May 23 21:38:50 alix-tst pppd[29491]: rcvd [CHAP Success id=0x1 ""]
May 23 21:38:50 alix-tst pppd[29491]: CHAP authentication succeeded
May 23 21:38:50 alix-tst pppd[29491]: CHAP authentication succeeded
May 23 21:38:50 alix-tst pppd[29491]: peer from calling number 00:90:1A:A0:3D:B9 authorized
May 23 21:38:50 alix-tst pppd[29491]: sent [IPCP ConfReq id=0x1 <addr 0.0.0.0> <ms-dns1 0.0.0.0> <ms-dns3 0.0.0.0>]
May 23 21:38:50 alix-tst pppd[29491]: sent [IPV6CP ConfReq id=0x1 <addr fe80::e0d4:2d3f:e674:e204>]
May 23 21:38:50 alix-tst pppd[29491]: rcvd [IPCP ConfReq id=0x1 <compress VJ 0f 01> <addr 212.25.27.37>]
May 23 21:38:50 alix-tst pppd[29491]: sent [IPCP ConfRej id=0x1 <compress VJ 0f 01>]
May 23 21:38:50 alix-tst pppd[29491]: rcvd [IPV6CP ConfReq id=0x1 <addr fe80::0219:56ff:fe99:49e0>]
May 23 21:38:50 alix-tst pppd[29491]: sent [IPV6CP ConfAck id=0x1 <addr fe80::0219:56ff:fe99:49e0>]
May 23 21:38:50 alix-tst pppd[29491]: rcvd [IPCP ConfNak id=0x1 <addr 212.25.16.1> <ms-dns1 212.25.28.55> <ms-dns3 194.246.118.118>]
May 23 21:38:50 alix-tst pppd[29491]: sent [IPCP ConfReq id=0x2 <addr 212.25.16.1> <ms-dns1 212.25.28.55> <ms-dns3 194.246.118.118>]
May 23 21:38:50 alix-tst pppd[29491]: rcvd [IPV6CP ConfAck id=0x1 <addr fe80::e0d4:2d3f:e674:e204>]
May 23 21:38:50 alix-tst pppd[29491]: local  LL address fe80::e0d4:2d3f:e674:e204
May 23 21:38:50 alix-tst pppd[29491]: remote LL address fe80::0219:56ff:fe99:49e0
May 23 21:38:50 alix-tst pppd[29491]: Script /etc/ppp/ipv6-up started (pid 29513)
May 23 21:38:50 alix-tst pppd[29491]: rcvd [IPCP ConfReq id=0x2 <addr 212.25.27.37>]
May 23 21:38:50 alix-tst pppd[29491]: sent [IPCP ConfAck id=0x2 <addr 212.25.27.37>]
May 23 21:38:50 alix-tst pppd[29491]: rcvd [IPCP ConfAck id=0x2 <addr 212.25.16.1> <ms-dns1 212.25.28.55> <ms-dns3 194.246.118.118>]
May 23 21:38:50 alix-tst pppd[29491]: Cannot determine ethernet address for proxy ARP
May 23 21:38:50 alix-tst pppd[29491]: local  IP address 212.25.16.1
May 23 21:38:50 alix-tst pppd[29491]: remote IP address 212.25.27.37
May 23 21:38:50 alix-tst pppd[29491]: primary   DNS address 212.25.28.55
May 23 21:38:50 alix-tst pppd[29491]: secondary DNS address 194.246.118.118
May 23 21:38:50 alix-tst pppd[29491]: Script /etc/ppp/ip-up started (pid 29516)
May 23 21:38:50 alix-tst pppd[29491]: Script /etc/ppp/ipv6-up finished (pid 29513), status = 0x0
May 23 21:38:50 alix-tst postfix/master[4248]: reload configuration /etc/postfix
May 23 21:38:50 alix-tst pppd[29491]: Script /etc/ppp/ip-up finished (pid 29516), status = 0x0

ppp0 Link encap:Point-to-Point Protocol
inet addr:212.25.16.1 P-t-P:212.25.27.37 Mask:255.255.255.255 inet6 addr: fe80::e0d4:2d3f:e674:e204/10 Scope:Link UP POINTOPOINT RUNNING NOARP MULTICAST MTU:1492 Metric:1 RX packets:12 errors:0 dropped:0 overruns:0 frame:0 TX packets:6 errors:0 dropped:0 overruns:0 carrier:0 collisions:0 txqueuelen:3
RX bytes:562 (562.0 B) TX bytes:92 (92.0 B)

net.ipv6.conf.all.forwarding=0

May 23 21:43:35 alix-tst pppd[32142]: Plugin rp-pppoe.so loaded.
May 23 21:43:35 alix-tst pppd[32143]: pppd 2.4.4 started by root, uid 0
May 23 21:43:36 alix-tst pppd[32143]: PADS: Service-Name: ''
May 23 21:43:36 alix-tst pppd[32143]: PPP session is 757
May 23 21:43:36 alix-tst pppd[32143]: using channel 11
May 23 21:43:36 alix-tst pppd[32143]: Using interface ppp0
May 23 21:43:36 alix-tst pppd[32143]: Connect: ppp0 <--> eth0
May 23 21:43:36 alix-tst pppd[32143]: sent [LCP ConfReq id=0x1 <mru 1492> <magic 0x7e7c4da8>]
May 23 21:43:36 alix-tst pppd[32143]: rcvd [LCP ConfReq id=0xad <mru 1492> <auth chap MD5> <magic 0x7598a7>]
May 23 21:43:36 alix-tst pppd[32143]: sent [LCP ConfAck id=0xad <mru 1492> <auth chap MD5> <magic 0x7598a7>]
May 23 21:43:36 alix-tst pppd[32143]: rcvd [LCP ConfAck id=0x1 <mru 1492> <magic 0x7e7c4da8>]
May 23 21:43:36 alix-tst pppd[32143]: sent [LCP EchoReq id=0x0 magic=0x7e7c4da8]
May 23 21:43:36 alix-tst pppd[32143]: rcvd [CHAP Challenge id=0x31 <ae504fb324a1da70f0f2d580402ab1ac>, name = "ipc-zhh790-r-br-03"]
May 23 21:43:36 alix-tst pppd[32143]: sent [CHAP Response id=0x31 <41629cee25511522e5d4b55e7f58c15a>, name = "dol/[email protected]"]
May 23 21:43:36 alix-tst pppd[32143]: rcvd [LCP EchoRep id=0x0 magic=0x7598a7]
May 23 21:43:36 alix-tst pppd[32143]: rcvd [LCP ConfReq id=0x1 <auth pap> <magic 0x59441d38>]
May 23 21:43:36 alix-tst pppd[32143]: sent [LCP ConfReq id=0x2 <mru 1492> <magic 0x14756caf>]
May 23 21:43:36 alix-tst pppd[32143]: sent [LCP ConfAck id=0x1 <auth pap> <magic 0x59441d38>]
May 23 21:43:36 alix-tst pppd[32143]: rcvd [LCP ConfAck id=0x2 <mru 1492> <magic 0x14756caf>]
May 23 21:43:36 alix-tst pppd[32143]: sent [LCP EchoReq id=0x0 magic=0x14756caf]
May 23 21:43:36 alix-tst pppd[32143]: sent [PAP AuthReq id=0x1 user="dol/[email protected]" password=<hidden>]
May 23 21:43:36 alix-tst pppd[32143]: rcvd [LCP ConfReq id=0x1 <mru 1492> <auth chap MD5> <magic 0x708f14c5>]
May 23 21:43:36 alix-tst pppd[32143]: sent [LCP ConfReq id=0x3 <mru 1492> <magic 0x653c44db>]
May 23 21:43:36 alix-tst pppd[32143]: sent [LCP ConfAck id=0x1 <mru 1492> <auth chap MD5> <magic 0x708f14c5>]
May 23 21:43:36 alix-tst pppd[32143]: rcvd [LCP ConfAck id=0x3 <mru 1492> <magic 0x653c44db>]
May 23 21:43:36 alix-tst pppd[32143]: sent [LCP EchoReq id=0x0 magic=0x653c44db]
May 23 21:43:36 alix-tst pppd[32143]: rcvd [CHAP Challenge id=0x1 <4df4d05ddfc7b9e3185c2143e82a0bab>, name = "brain.glb"]
May 23 21:43:36 alix-tst pppd[32143]: sent [CHAP Response id=0x1 <7833c4a255c53c29b4256e6c129b8718>, name = "dol/[email protected]"]
May 23 21:43:36 alix-tst pppd[32143]: rcvd [LCP EchoRep id=0x0 magic=0x708f14c5]
May 23 21:43:36 alix-tst pppd[32143]: rcvd [CHAP Success id=0x1 ""]
May 23 21:43:36 alix-tst pppd[32143]: CHAP authentication succeeded
May 23 21:43:36 alix-tst pppd[32143]: CHAP authentication succeeded
May 23 21:43:36 alix-tst pppd[32143]: peer from calling number 00:90:1A:A0:3D:B9 authorized
May 23 21:43:36 alix-tst pppd[32143]: sent [IPCP ConfReq id=0x1 <addr 0.0.0.0> <ms-dns1 0.0.0.0> <ms-dns3 0.0.0.0>]
May 23 21:43:36 alix-tst pppd[32143]: sent [IPV6CP ConfReq id=0x1 <addr fe80::91af:5025:4398:606b>]
May 23 21:43:36 alix-tst pppd[32143]: rcvd [IPCP ConfReq id=0x1 <compress VJ 0f 01> <addr 212.25.27.37>]
May 23 21:43:36 alix-tst pppd[32143]: sent [IPCP ConfRej id=0x1 <compress VJ 0f 01>]
May 23 21:43:36 alix-tst pppd[32143]: rcvd [IPV6CP ConfReq id=0x1 <addr fe80::0219:56ff:fe99:49e0>]
May 23 21:43:36 alix-tst pppd[32143]: sent [IPV6CP ConfAck id=0x1 <addr fe80::0219:56ff:fe99:49e0>]
May 23 21:43:36 alix-tst pppd[32143]: rcvd [IPCP ConfNak id=0x1 <addr 212.25.16.1> <ms-dns1 212.25.28.55> <ms-dns3 194.246.118.118>]
May 23 21:43:36 alix-tst pppd[32143]: sent [IPCP ConfReq id=0x2 <addr 212.25.16.1> <ms-dns1 212.25.28.55> <ms-dns3 194.246.118.118>]
May 23 21:43:36 alix-tst pppd[32143]: rcvd [IPV6CP ConfAck id=0x1 <addr fe80::91af:5025:4398:606b>]
May 23 21:43:36 alix-tst pppd[32143]: local  LL address fe80::91af:5025:4398:606b
May 23 21:43:36 alix-tst pppd[32143]: remote LL address fe80::0219:56ff:fe99:49e0
May 23 21:43:36 alix-tst pppd[32143]: Script /etc/ppp/ipv6-up started (pid 32150)
May 23 21:43:36 alix-tst pppd[32143]: rcvd [IPCP ConfReq id=0x2 <addr 212.25.27.37>]
May 23 21:43:36 alix-tst pppd[32143]: sent [IPCP ConfAck id=0x2 <addr 212.25.27.37>]
May 23 21:43:36 alix-tst pppd[32143]: Script /etc/ppp/ipv6-up finished (pid 32150), status = 0x0
May 23 21:43:36 alix-tst pppd[32143]: rcvd [IPCP ConfAck id=0x2 <addr 212.25.16.1> <ms-dns1 212.25.28.55> <ms-dns3 194.246.118.118>]
May 23 21:43:36 alix-tst pppd[32143]: Cannot determine ethernet address for proxy ARP
May 23 21:43:36 alix-tst pppd[32143]: local  IP address 212.25.16.1
May 23 21:43:36 alix-tst pppd[32143]: remote IP address 212.25.27.37
May 23 21:43:36 alix-tst pppd[32143]: primary   DNS address 212.25.28.55
May 23 21:43:36 alix-tst pppd[32143]: secondary DNS address 194.246.118.118
May 23 21:43:36 alix-tst pppd[32143]: Script /etc/ppp/ip-up started (pid 32153)
May 23 21:43:37 alix-tst pppd[32143]: Script /etc/ppp/ip-up finished (pid 32153), status = 0x0

ppp0 Link encap:Point-to-Point Protocol

          inet addr:212.25.16.1  P-t-P:212.25.27.37  Mask:255.255.255.255
          inet6 addr: 2001:8e0:1000:b:91af:5025:4398:606b/64 Scope:Global
          inet6 addr: fe80::91af:5025:4398:606b/10 Scope:Link
          UP POINTOPOINT RUNNING NOARP MULTICAST  MTU:1492  Metric:1
          RX packets:20 errors:0 dropped:0 overruns:0 frame:0
          TX packets:18 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:3
          RX bytes:1290 (1.2 KiB)  TX bytes:1276 (1.2 KiB)

Signature · 4 lines

Matthias Cramer                System & Network Manager
Interway Communication GmbH    Phone +41 43 500 1111
Josefstrasse 225               Fax   +41 44 271 3535
CH-8005 Zuerich                http://www.interway.ch/

James Chapman

2008-05-23 21:34 UTC #6 lore raw

Quoted 11 lines · Matthias Cramer

Hi James
Quoted 8 lines · James Chapman
Quoted 7 lines · Matthias Cramer
Quoted 1 line · James Chapman
Did this work with previous kernel versions?
No, in my opinion it never worked. But I thought that pppd does it wrong because id never got an IPv6 address. But I had always forwarding enabled. Now in this case i started pppd without forwarding enabled and got an address.

Quoted 6 lines

Quoted 4 lines
Quoted 2 lines
Quoted 1 line
Does pppd log any errors?
No, no errors
Could you post a pppd debug log showing the ppp protocol exchange with the peer in the failing case? It might give some clues.
Here the logs ... First with forwarding enabled and second with disabled ...

Thanks. The 2 logs show the same PPP packets are exchanged in each case. The only difference that I spotted is the order in which the ip-up and ip6-up scripts are called. In the working case, ip6-up starts and finishes before ip-up starts. In the failing case, ip-up starts before ip6-up finishes. What do these scripts do? What might happen if they both run at the same time?

Quoted 142 lines

net.ipv6.conf.all.forwarding=1

May 23 21:38:49 alix-tst pppd[29490]: Plugin rp-pppoe.so loaded.
May 23 21:38:49 alix-tst pppd[29491]: pppd 2.4.4 started by root, uid 0
May 23 21:38:49 alix-tst pppd[29491]: PADS: Service-Name: ''
May 23 21:38:49 alix-tst pppd[29491]: PPP session is 675
May 23 21:38:49 alix-tst pppd[29491]: using channel 10
May 23 21:38:49 alix-tst pppd[29491]: Using interface ppp0
May 23 21:38:49 alix-tst pppd[29491]: Connect: ppp0 <--> eth0
May 23 21:38:49 alix-tst pppd[29491]: sent [LCP ConfReq id=0x1 <mru 1492> <magic 0xadacf61b>]
May 23 21:38:49 alix-tst pppd[29491]: rcvd [LCP ConfReq id=0xc8 <mru 1492> <auth chap MD5> <magic 0x6887033f>]
May 23 21:38:49 alix-tst pppd[29491]: sent [LCP ConfAck id=0xc8 <mru 1492> <auth chap MD5> <magic 0x6887033f>]
May 23 21:38:49 alix-tst pppd[29491]: rcvd [LCP ConfAck id=0x1 <mru 1492> <magic 0xadacf61b>]
May 23 21:38:49 alix-tst pppd[29491]: sent [LCP EchoReq id=0x0 magic=0xadacf61b]
May 23 21:38:49 alix-tst pppd[29491]: rcvd [CHAP Challenge id=0xa7 <c3ca04555d0b05c824913a485207145a>, name = "ipc-zhh790-r-br-03"]
May 23 21:38:49 alix-tst pppd[29491]: sent [CHAP Response id=0xa7 <4e5f2e265676afd4426f96a4f3d69d98>, name = "dol/[email protected]"]
May 23 21:38:49 alix-tst pppd[29491]: rcvd [LCP EchoRep id=0x0 magic=0x6887033f]
May 23 21:38:50 alix-tst pppd[29491]: rcvd [LCP ConfReq id=0x1 <auth pap> <magic 0x81e3711d>]
May 23 21:38:50 alix-tst pppd[29491]: sent [LCP ConfReq id=0x2 <mru 1492> <magic 0xe78877a6>]
May 23 21:38:50 alix-tst pppd[29491]: sent [LCP ConfAck id=0x1 <auth pap> <magic 0x81e3711d>]
May 23 21:38:50 alix-tst pppd[29491]: rcvd [LCP ConfAck id=0x2 <mru 1492> <magic 0xe78877a6>]
May 23 21:38:50 alix-tst pppd[29491]: sent [LCP EchoReq id=0x0 magic=0xe78877a6]
May 23 21:38:50 alix-tst pppd[29491]: sent [PAP AuthReq id=0x1 user="dol/[email protected]" password=<hidden>]
May 23 21:38:50 alix-tst pppd[29491]: rcvd [LCP ConfReq id=0x1 <mru 1492> <auth chap MD5> <magic 0x708ab66f>]
May 23 21:38:50 alix-tst pppd[29491]: sent [LCP ConfReq id=0x3 <mru 1492> <magic 0xade5da06>]
May 23 21:38:50 alix-tst pppd[29491]: sent [LCP ConfAck id=0x1 <mru 1492> <auth chap MD5> <magic 0x708ab66f>]
May 23 21:38:50 alix-tst pppd[29491]: rcvd [LCP ConfAck id=0x3 <mru 1492> <magic 0xade5da06>]
May 23 21:38:50 alix-tst pppd[29491]: sent [LCP EchoReq id=0x0 magic=0xade5da06]
May 23 21:38:50 alix-tst pppd[29491]: rcvd [CHAP Challenge id=0x1 <5de7704ca9b8440a185c21438e465653>, name = "brain.glb"]
May 23 21:38:50 alix-tst pppd[29491]: sent [CHAP Response id=0x1 <7cca580881d4ca01c3f191382ec97df2>, name = "dol/[email protected]"]
May 23 21:38:50 alix-tst pppd[29491]: rcvd [LCP EchoRep id=0x0 magic=0x708ab66f]
May 23 21:38:50 alix-tst pppd[29491]: rcvd [CHAP Success id=0x1 ""]
May 23 21:38:50 alix-tst pppd[29491]: CHAP authentication succeeded
May 23 21:38:50 alix-tst pppd[29491]: CHAP authentication succeeded
May 23 21:38:50 alix-tst pppd[29491]: peer from calling number 00:90:1A:A0:3D:B9 authorized
May 23 21:38:50 alix-tst pppd[29491]: sent [IPCP ConfReq id=0x1 <addr 0.0.0.0> <ms-dns1 0.0.0.0> <ms-dns3 0.0.0.0>]
May 23 21:38:50 alix-tst pppd[29491]: sent [IPV6CP ConfReq id=0x1 <addr fe80::e0d4:2d3f:e674:e204>]
May 23 21:38:50 alix-tst pppd[29491]: rcvd [IPCP ConfReq id=0x1 <compress VJ 0f 01> <addr 212.25.27.37>]
May 23 21:38:50 alix-tst pppd[29491]: sent [IPCP ConfRej id=0x1 <compress VJ 0f 01>]
May 23 21:38:50 alix-tst pppd[29491]: rcvd [IPV6CP ConfReq id=0x1 <addr fe80::0219:56ff:fe99:49e0>]
May 23 21:38:50 alix-tst pppd[29491]: sent [IPV6CP ConfAck id=0x1 <addr fe80::0219:56ff:fe99:49e0>]
May 23 21:38:50 alix-tst pppd[29491]: rcvd [IPCP ConfNak id=0x1 <addr 212.25.16.1> <ms-dns1 212.25.28.55> <ms-dns3 194.246.118.118>]
May 23 21:38:50 alix-tst pppd[29491]: sent [IPCP ConfReq id=0x2 <addr 212.25.16.1> <ms-dns1 212.25.28.55> <ms-dns3 194.246.118.118>]
May 23 21:38:50 alix-tst pppd[29491]: rcvd [IPV6CP ConfAck id=0x1 <addr fe80::e0d4:2d3f:e674:e204>]
May 23 21:38:50 alix-tst pppd[29491]: local  LL address fe80::e0d4:2d3f:e674:e204
May 23 21:38:50 alix-tst pppd[29491]: remote LL address fe80::0219:56ff:fe99:49e0
May 23 21:38:50 alix-tst pppd[29491]: Script /etc/ppp/ipv6-up started (pid 29513)
May 23 21:38:50 alix-tst pppd[29491]: rcvd [IPCP ConfReq id=0x2 <addr 212.25.27.37>]
May 23 21:38:50 alix-tst pppd[29491]: sent [IPCP ConfAck id=0x2 <addr 212.25.27.37>]
May 23 21:38:50 alix-tst pppd[29491]: rcvd [IPCP ConfAck id=0x2 <addr 212.25.16.1> <ms-dns1 212.25.28.55> <ms-dns3 194.246.118.118>]
May 23 21:38:50 alix-tst pppd[29491]: Cannot determine ethernet address for proxy ARP
May 23 21:38:50 alix-tst pppd[29491]: local  IP address 212.25.16.1
May 23 21:38:50 alix-tst pppd[29491]: remote IP address 212.25.27.37
May 23 21:38:50 alix-tst pppd[29491]: primary   DNS address 212.25.28.55
May 23 21:38:50 alix-tst pppd[29491]: secondary DNS address 194.246.118.118
May 23 21:38:50 alix-tst pppd[29491]: Script /etc/ppp/ip-up started (pid 29516)
May 23 21:38:50 alix-tst pppd[29491]: Script /etc/ppp/ipv6-up finished (pid 29513), status = 0x0
May 23 21:38:50 alix-tst postfix/master[4248]: reload configuration /etc/postfix
May 23 21:38:50 alix-tst pppd[29491]: Script /etc/ppp/ip-up finished (pid 29516), status = 0x0

net.ipv6.conf.all.forwarding=0

May 23 21:43:35 alix-tst pppd[32142]: Plugin rp-pppoe.so loaded.
May 23 21:43:35 alix-tst pppd[32143]: pppd 2.4.4 started by root, uid 0
May 23 21:43:36 alix-tst pppd[32143]: PADS: Service-Name: ''
May 23 21:43:36 alix-tst pppd[32143]: PPP session is 757
May 23 21:43:36 alix-tst pppd[32143]: using channel 11
May 23 21:43:36 alix-tst pppd[32143]: Using interface ppp0
May 23 21:43:36 alix-tst pppd[32143]: Connect: ppp0 <--> eth0
May 23 21:43:36 alix-tst pppd[32143]: sent [LCP ConfReq id=0x1 <mru 1492> <magic 0x7e7c4da8>]
May 23 21:43:36 alix-tst pppd[32143]: rcvd [LCP ConfReq id=0xad <mru 1492> <auth chap MD5> <magic 0x7598a7>]
May 23 21:43:36 alix-tst pppd[32143]: sent [LCP ConfAck id=0xad <mru 1492> <auth chap MD5> <magic 0x7598a7>]
May 23 21:43:36 alix-tst pppd[32143]: rcvd [LCP ConfAck id=0x1 <mru 1492> <magic 0x7e7c4da8>]
May 23 21:43:36 alix-tst pppd[32143]: sent [LCP EchoReq id=0x0 magic=0x7e7c4da8]
May 23 21:43:36 alix-tst pppd[32143]: rcvd [CHAP Challenge id=0x31 <ae504fb324a1da70f0f2d580402ab1ac>, name = "ipc-zhh790-r-br-03"]
May 23 21:43:36 alix-tst pppd[32143]: sent [CHAP Response id=0x31 <41629cee25511522e5d4b55e7f58c15a>, name = "dol/[email protected]"]
May 23 21:43:36 alix-tst pppd[32143]: rcvd [LCP EchoRep id=0x0 magic=0x7598a7]
May 23 21:43:36 alix-tst pppd[32143]: rcvd [LCP ConfReq id=0x1 <auth pap> <magic 0x59441d38>]
May 23 21:43:36 alix-tst pppd[32143]: sent [LCP ConfReq id=0x2 <mru 1492> <magic 0x14756caf>]
May 23 21:43:36 alix-tst pppd[32143]: sent [LCP ConfAck id=0x1 <auth pap> <magic 0x59441d38>]
May 23 21:43:36 alix-tst pppd[32143]: rcvd [LCP ConfAck id=0x2 <mru 1492> <magic 0x14756caf>]
May 23 21:43:36 alix-tst pppd[32143]: sent [LCP EchoReq id=0x0 magic=0x14756caf]
May 23 21:43:36 alix-tst pppd[32143]: sent [PAP AuthReq id=0x1 user="dol/[email protected]" password=<hidden>]
May 23 21:43:36 alix-tst pppd[32143]: rcvd [LCP ConfReq id=0x1 <mru 1492> <auth chap MD5> <magic 0x708f14c5>]
May 23 21:43:36 alix-tst pppd[32143]: sent [LCP ConfReq id=0x3 <mru 1492> <magic 0x653c44db>]
May 23 21:43:36 alix-tst pppd[32143]: sent [LCP ConfAck id=0x1 <mru 1492> <auth chap MD5> <magic 0x708f14c5>]
May 23 21:43:36 alix-tst pppd[32143]: rcvd [LCP ConfAck id=0x3 <mru 1492> <magic 0x653c44db>]
May 23 21:43:36 alix-tst pppd[32143]: sent [LCP EchoReq id=0x0 magic=0x653c44db]
May 23 21:43:36 alix-tst pppd[32143]: rcvd [CHAP Challenge id=0x1 <4df4d05ddfc7b9e3185c2143e82a0bab>, name = "brain.glb"]
May 23 21:43:36 alix-tst pppd[32143]: sent [CHAP Response id=0x1 <7833c4a255c53c29b4256e6c129b8718>, name = "dol/[email protected]"]
May 23 21:43:36 alix-tst pppd[32143]: rcvd [LCP EchoRep id=0x0 magic=0x708f14c5]
May 23 21:43:36 alix-tst pppd[32143]: rcvd [CHAP Success id=0x1 ""]
May 23 21:43:36 alix-tst pppd[32143]: CHAP authentication succeeded
May 23 21:43:36 alix-tst pppd[32143]: CHAP authentication succeeded
May 23 21:43:36 alix-tst pppd[32143]: peer from calling number 00:90:1A:A0:3D:B9 authorized
May 23 21:43:36 alix-tst pppd[32143]: sent [IPCP ConfReq id=0x1 <addr 0.0.0.0> <ms-dns1 0.0.0.0> <ms-dns3 0.0.0.0>]
May 23 21:43:36 alix-tst pppd[32143]: sent [IPV6CP ConfReq id=0x1 <addr fe80::91af:5025:4398:606b>]
May 23 21:43:36 alix-tst pppd[32143]: rcvd [IPCP ConfReq id=0x1 <compress VJ 0f 01> <addr 212.25.27.37>]
May 23 21:43:36 alix-tst pppd[32143]: sent [IPCP ConfRej id=0x1 <compress VJ 0f 01>]
May 23 21:43:36 alix-tst pppd[32143]: rcvd [IPV6CP ConfReq id=0x1 <addr fe80::0219:56ff:fe99:49e0>]
May 23 21:43:36 alix-tst pppd[32143]: sent [IPV6CP ConfAck id=0x1 <addr fe80::0219:56ff:fe99:49e0>]
May 23 21:43:36 alix-tst pppd[32143]: rcvd [IPCP ConfNak id=0x1 <addr 212.25.16.1> <ms-dns1 212.25.28.55> <ms-dns3 194.246.118.118>]
May 23 21:43:36 alix-tst pppd[32143]: sent [IPCP ConfReq id=0x2 <addr 212.25.16.1> <ms-dns1 212.25.28.55> <ms-dns3 194.246.118.118>]
May 23 21:43:36 alix-tst pppd[32143]: rcvd [IPV6CP ConfAck id=0x1 <addr fe80::91af:5025:4398:606b>]
May 23 21:43:36 alix-tst pppd[32143]: local  LL address fe80::91af:5025:4398:606b
May 23 21:43:36 alix-tst pppd[32143]: remote LL address fe80::0219:56ff:fe99:49e0
May 23 21:43:36 alix-tst pppd[32143]: Script /etc/ppp/ipv6-up started (pid 32150)
May 23 21:43:36 alix-tst pppd[32143]: rcvd [IPCP ConfReq id=0x2 <addr 212.25.27.37>]
May 23 21:43:36 alix-tst pppd[32143]: sent [IPCP ConfAck id=0x2 <addr 212.25.27.37>]
May 23 21:43:36 alix-tst pppd[32143]: Script /etc/ppp/ipv6-up finished (pid 32150), status = 0x0
May 23 21:43:36 alix-tst pppd[32143]: rcvd [IPCP ConfAck id=0x2 <addr 212.25.16.1> <ms-dns1 212.25.28.55> <ms-dns3 194.246.118.118>]
May 23 21:43:36 alix-tst pppd[32143]: Cannot determine ethernet address for proxy ARP
May 23 21:43:36 alix-tst pppd[32143]: local  IP address 212.25.16.1
May 23 21:43:36 alix-tst pppd[32143]: remote IP address 212.25.27.37
May 23 21:43:36 alix-tst pppd[32143]: primary   DNS address 212.25.28.55
May 23 21:43:36 alix-tst pppd[32143]: secondary DNS address 194.246.118.118
May 23 21:43:36 alix-tst pppd[32143]: Script /etc/ppp/ip-up started (pid 32153)
May 23 21:43:37 alix-tst pppd[32143]: Script /etc/ppp/ip-up finished (pid 32153), status = 0x0

ppp0 Link encap:Point-to-Point Protocol

          inet addr:212.25.16.1  P-t-P:212.25.27.37  Mask:255.255.255.255
          inet6 addr: 2001:8e0:1000:b:91af:5025:4398:606b/64 Scope:Global
          inet6 addr: fe80::91af:5025:4398:606b/10 Scope:Link
          UP POINTOPOINT RUNNING NOARP MULTICAST  MTU:1492  Metric:1
          RX packets:20 errors:0 dropped:0 overruns:0 frame:0
          TX packets:18 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:3
          RX bytes:1290 (1.2 KiB)  TX bytes:1276 (1.2 KiB)

Signature · 4 lines

James Chapman
Katalix Systems Ltd
http://www.katalix.com
Catalysts for your Embedded Linux software development

Willy Tarreau

2008-05-24 04:29 UTC #7 lore raw

In reply to Matthias Cramer

Quoted 28 lines · Matthias Cramer

Quoted 11 lines · James Chapman
Quoted 10 lines · Andrew Morton
Quoted 8 lines · On Wed, 21 May 2008 14:56:43 +0200 Matthias Cramer…
I have a very wired behaviour when doing IPv6 over PPPoE.
The situation:
A linux box connected to a DSL Modem, on the other side is a Cisco LNS which terminates the PPP session (actually L2TP).
I have control over both ends.
Quoted 7 lines
Quoted 5 lines
Quoted 5 lines
When I have net.ipv6.conf.all.forwarding set to 0 then the ppp Interface gets a IPv6 address from the Cisco via IP6CP. When I have net.ipv6.conf.all.forwarding set to 1 them the ppp Interface does not get an address, it has only a normal link local address.
What do you mean by normal link local address?
a fe80:: address, which every IPv6 enabled Interface has...
Quoted 6 lines
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When I start the ppp session with forwarding set to 0 I can ping out and there exists a default route to ppp0 , then I switch forwarding to 1 the default route disappears and therefore routing does not work any longer.

Quoted 6 lines

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Did this work with previous kernel versions?
No, in my opinion it never worked. But I thought that pppd does it wrong because id never got an IPv6 address. But I had always forwarding enabled. Now in this case i started pppd without forwarding enabled and got an address.

Well, at least it has been working for years in kernel 2.4 for me with pppd 2.4.2b3 to 2.4.4 (I've not upgraded my firewall to 2.6 yet). So it has definitely been working at some point.

Willy

Pascal Hambourg

2008-05-28 10:34 UTC #8 lore raw

Hello all,

Quoted 17 lines · Willy Tarreau a écrit/

Quoted 15 lines · Matthias Cramer
Quoted 13 lines · James Chapman
Quoted 11 lines · Andrew Morton
Quoted 8 lines · On Wed, 21 May 2008 14:56:43 +0200 Matthias Cramer…
I have a very wired behaviour when doing IPv6 over PPPoE.
The situation:
A linux box connected to a DSL Modem, on the other side is a Cisco LNS which terminates the PPP session (actually L2TP).
I have control over both ends.

Quoted 5 lines

Quoted 5 lines
Quoted 5 lines
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When I have net.ipv6.conf.all.forwarding set to 0 then the ppp Interface gets a IPv6 address from the Cisco via IP6CP. When I have net.ipv6.conf.all.forwarding set to 1 them the ppp Interface does not get an address, it has only a normal link local address.

AFAIK IPV6CP/PPP only allows to negotiate link local addresses. So I guess the global address and default route is assigned by another mechanism, maybe stateless autoconfiguration using router advertisement, although I was not aware it could be used on a PPP link because of the absence of MAC address. Enabling global forwarding (net.ipv6.conf.all.forwarding=1) disables stateless autoconfiguration (see ip-sysctl.txt in kernel documentation) on all interfaces. I believe this is consistent with the observed behaviour.

Quoted 4 lines

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When I start the ppp session with forwarding set to 0 I can ping out and there exists a default route to ppp0 , then I switch forwarding to 1 the default route disappears and therefore routing does not work any longer.

I have read reports about this. I guess the logic is that enabling forwarding turns the box into a router, so the default route learned from another router's advertisements by autoconfiguration should be deleted. Even the autoconfigured global address will eventually expire.

Quoted 3 lines

Well, at least it has been working for years in kernel 2.4 for me with pppd 2.4.2b3 to 2.4.4 (I've not upgraded my firewall to 2.6 yet). So it has definitely been working at some point.

What exactly has been working ?

PS : Willy, do you plan to backport the security fix for the sit module from 2.6.25.3 into 2.4 ?

Willy Tarreau

2008-05-28 12:45 UTC #9 lore raw

Hi,

Quoted 20 lines · Pascal Hambourg

Hello all,
Quoted 17 lines · Willy Tarreau a écrit/
Quoted 15 lines · Matthias Cramer
Quoted 13 lines · James Chapman
Quoted 11 lines · Andrew Morton
Quoted 8 lines · On Wed, 21 May 2008 14:56:43 +0200 Matthias Cramer…
I have a very wired behaviour when doing IPv6 over PPPoE.
The situation:
A linux box connected to a DSL Modem, on the other side is a Cisco LNS which terminates the PPP session (actually L2TP).
I have control over both ends.

Quoted 7 lines

Quoted 5 lines
Quoted 5 lines
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Quoted 5 lines
When I have net.ipv6.conf.all.forwarding set to 0 then the ppp Interface gets a IPv6 address from the Cisco via IP6CP. When I have net.ipv6.conf.all.forwarding set to 1 them the ppp Interface does not get an address, it has only a normal link local address.
AFAIK IPV6CP/PPP only allows to negotiate link local addresses.

right.

Quoted 20 lines

So I
guess the global address and default route is assigned by another mechanism, maybe stateless autoconfiguration using router advertisement, although I was not aware it could be used on a PPP link because of the absence of MAC address. Enabling global forwarding (net.ipv6.conf.all.forwarding=1) disables stateless autoconfiguration (see ip-sysctl.txt in kernel documentation) on all interfaces. I believe this is consistent with the observed behaviour.
Quoted 5 lines
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Quoted 5 lines
When I start the ppp session with forwarding set to 0 I can ping out and there exists a default route to ppp0 , then I switch forwarding to 1
the default route disappears and therefore routing does not work any longer.
I have read reports about this. I guess the logic is that enabling forwarding turns the box into a router, so the default route learned from another router's advertisements by autoconfiguration should be deleted. Even the autoconfigured global address will eventually expire.

Quoted 5 lines

Quoted 3 lines
Well, at least it has been working for years in kernel 2.4 for me with pppd 2.4.2b3 to 2.4.4 (I've not upgraded my firewall to 2.6 yet). So it has definitely been working at some point.
What exactly has been working ?

Sorry, I understood that IPv6 addresses got lost when IP forwarding was set to 1, which sounded strange to me. I've re-read the original mail more carefully and noticed that it was _autoconfiguration_ which does not work. For this, I don't know as I don't use it. My bad.

Quoted 2 lines

PS : Willy, do you plan to backport the security fix for the sit module from 2.6.25.3 into 2.4 ?

Yes, any security fix must be backported when appropriate. I just don't remember about this one, maybe I missed it. Care to send a pointer to the commit in 2.6 ?

Thanks,
Willy