Re: [mpls-linux-general] [mpls example]another question

[James R. L. <jl...@mi...>]

Thinking back on this, in your config you created a loop!
Packets get put on the LSP 1000 at LER1, they loop onto LSP 1002 at
LER2, then LER1 loops them back onto LSP 1000.  It would be interesting
to see what the ILM/NHLFE counters looked like after sending one ping
packet....  just throught I'd mention it.

On Wed, Dec 21, 2005 at 08:43:44AM -0600, James R. Leu wrote:
> First, you need to work on your ascii-art-foo a bit :-)
> -don't use tabs
> -use a 80 column, fixed font, text editor (vi, emacs)
>=20
> I've cleaned up your drawing:
>  =20
>                         192.168.101.0/24               192.168.103.0/24
>                                |                              |
>                                |                              |
>  ------eth0    eth0------eth1  v  eth1----eth0  eth0---eth1   v   eth1---=
---
> | HostA |--------| LER1  |---------|  LSR  |-----|  LER2 |----------| Hos=
tB |
>  ------.10  ^   20-------20        30-----30  ^  40-----40          50---=
---
>             |                                 |
>             |                                 |=20
>       192.168.100.0/24                  192.168.102.0/24
>=20
>=20
> Comments in-line...
>=20
> >  Configuration
> >  =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=
=3D=3D=3D=3D=3D=3D
> >   HostA
> >  ------
> >  ip route add 192.168.103.50/32 via 192.168.100.20
> >=20
> >  LER1
> >  ------
> >  mpls nhlfe add key 0 instructions push gen 1000 nexthop eth0 ipv4 192.=
168.100.20
> >  ip route add 192.168.103.50/32 via 192.168.101.30 spec_nh 0x8847 0x2
> >  mpls labelspace add dev eth1 labelspace 0
> >  mpls ilm add label gen 1002 labelspace 0
> >  mpls xc add ilm_label gen 1002 ilm_labelspace 0 nhlfe_key 0x2
>=20
> No XC required.  At the simplest level XCs are used for
> labelswaping, therefor they are not used on LERS.
>=20
> >  LSR
> >  -----
> >  mpls nhlfe add key 0 instructions push gen 1000 nexthop eth0 ipv4 192.=
168.102.40
> >  mpls nhlfe add key 0 instructions push gen 1002 nexthop eth1 ipv4 192.=
168.101.20
> >  ip route add 192.168.103.50/32 via 192.168.102.40 spec_nh 0x8847 0x2
> >  ip route add 192.168.100.10/32 via 192.168.101.20 spec_nh 0x8847 0x3
> >  mpls labelspace add dev eth0 labelspace 0
> >  mpls labelspace add dev eth1 labelspace 0
> >  mpls ilm add label gen 1000 labelspace 0
> >  mpls ilm add label gen 1002 labelspace 0=20
> >  mpls xc add ilm_label gen 1000 ilm_labelspace 0 nhlfe_key 0x2
> >  mpls xc add ilm_label gen 1002 ilm_labelspace 0 nhlfe_key 0x3
>=20
> No need for the 'ip route' statements.  You're labelswaping here, the
> packets will never leaves the MPLS stack, therefore they will never see
> the IPv4 routing table.
>=20
> >  LER2
> >  -----
> >  mpls nhlfe add key 0 instructions push gen 1002 nexthop eth1 ipv4 192.=
168.103.40
> >  ip route add 192.168.100.10/32 via 192.168.103.40 spec_nh 0x8847 0x2
> >  mpls labelspace add dev eth0 labelspace 0
> >  mpls ilm add label gen 1000 labelspace 0
> >  mpls xc add ilm_label gen 1000 ilm_labelspace 0 nhlfe_key 0x2
>=20
> Again no XCs on LERs.
>=20
> >  HostB
> >  ------
> >  ip route add 192.168.100.10/32 via 192.168.103.40
> --=20
> James R. Leu
> jl...@mi...



--=20
James R. Leu
jl...@mi...