Re: [mpls-linux-devel] LDP Configuation

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Make sure you have the mpls4 module loaded into the kernel
otherwise all attempts by LDP to install a ILM or NHLFE will fail, causing
the LDP sessions to fail.

You can also check what is happening at the kernel level by looking
at the output of 'dmesg'.  It will probably show all sorts of MPLS related
debug.

Finally, after a failed attempt by LDP, make sure you manually clean
up the ILMs and NHLFEs.

On Wed, Nov 22, 2006 at 03:18:59PM +0100, Sienes Rodr?guez Gonzalo wrote:
> Hi!
>=20
> Thanks for your information.
>=20
> I decided to test the new configuration in the following scenario, only w=
ith
> two routers to realized what LDP really does. =20
>=20
>       13.0.0.0/24   .1   .1             .2   .1   14.0.0.0/24
>                -------PE1-----------------PE3-------
>                   eth2   eth1         eth0   eth2
>                             12.0.0.0/24  =20
>=20
> These are the .conf files I use for PE1:
>=20
> ZEBRA
> ------------------------------------------------------------------
> !
> hostname PE1
> password root
> log file /var/log/quagga/zebra.log
> debug zebra events
> debug zebra kernel
> !
> !
> interface lo
> !
> !
> interface eth1
> !
> interface eth2
> !
> !
>=20
> OSPFD
> ------------------------------------------------------------------
> !
> hostname PE1
> password root
> log file /var/log/quagga/ospfd.log
> !
> !
> !
> interface eth1
>  description 12.0.0.1 netmask 255.255.255.0 broadcast 12.0.0.255 ! interf=
ace
> eth2  description 13.0.0.1 netmask 255.255.255.0 broadcast 13.0.0.255 !
> interface lo ! router ospf  ospf router-id 0.0.0.1  network 12.0.0.0/24 a=
rea
> 0  network 13.0.0.0/24 area 0 ! line vty !
>=20
> LDPD
> ------------------------------------------------------------------
> !
> hostname PE1
> password root
> log file /var/log/quagga/ldpd.log
> !
> interface eth1
>  mpls ip
> !
> interface eth2
> !
> interface lo
> !
> !
> line vty
> !
>=20
> VTYSH
> ------------------------------------------------------------------
> !
> service integrated-vtysh-config
> hostname PE1
> !
>=20
> As you suggested, after running all those daemons (zebra -d, ospfd -d,
> ldpd-d) I type "vtysh" to finally set the proper LDPD commands: "mpls ldp=
",
> and in each interface of 12.0.0.0/24 subnet, "mpls ip" and "mpls labelspa=
ce
> 0".
>=20
> I got some problems with mpls labelspace, cause sometimes when I type the
> command occurs an I/O error and the daemon zebra is killed. In the end, w=
hen
> it works, I capture the traffic and this is what happens:
>=20
> 1.Both PEs pass the stage of discovering with HELLO messages.
>=20
> 2.I can see INITIALIZATION messages in both ways, but the ones from 12.2 =
to
> 12.1 have a TCP checksum error. However, the LDP message seems to be
> correct. With correct LSRs identifiers and these session parameters:
>=20
>         -Downstream unsolicited mode.
>         -Loop detection disabled.
>         -MPLS labelspace 0.
>=20
> 3.The KEEPALIVEs in the way PE1 also travel with checksum error as well as
> all types of LDP messages but HELLOs. The ADDRESS messages are set with t=
he
> correct values of neighbor address.
>=20
> 4.The LABEL MAPPING messages carry the value of a label inside, which is =
the
> same for both ways, 10000.
>=20
> 5.The problem is that after distributing the labels, 12.1 sends to 12.2 a
> NOTIFICATION message with the status: fatal error, session rejected and t=
hen
> the process starts again, now exchanging different values of labels (alwa=
ys
> the same in both ways) 10001, 10002 and so on.
>=20
> This is what I get in PE1 and the same in PE2 with other addresses:
>=20
> PE1# sh ldp neig
> Peer LDP Ident: 14.0.0.1:0; Local LDP Ident: 13.0.0.1:0
>         TCP connection: 0.0.0.0.646 - 12.0.0.2.45099
>         State: OPERATIONAL; Msgs sent/recv: 489/1459; UNSOLICITED
>         Up time: 02:00:24
>         LDP discovery sources:
>           eth1
>         Addresses bound to peer:
>           12.0.0.2        14.0.0.1
>=20
> I try to do: ping -c3 14.0.0.1 from PE1, but the ICMP packets don't carry
> any LDP label. Besides, MPLS NHLFE and MPLS ILM tables are empty.
>=20
> Is this the expected behavior?
>=20
> Thanks in advance,
>=20
> Gonzalo
>=20
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--=20
James R. Leu
jl...@mi...