Re: [mpls-linux-general] how to change the ttl when switching from mpls to ip

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

I'm betting you've found a bug with the 'advanced feature' I referred to
yesterday.

Please try this, for each direction remove the "mpls xc" on the egress
LER and then add an IP route for the egress hosts 'dummy0'.

Assuming you have executed all of the commands in the Two LER, one LSR exam=
ple,
here is how to 'undo' the 'advanced feature':

traffic from A to B, modify LER2 as such:

    mpls xc delete ilm_label gen 1001 ilm_labelspace 0 nhlfe_key 0x2
    ip route add 10.0.0.2/32 via 192.168.1.5

traffic from B to A, modify LER1 as such:

    mpls xc delete ilm_label gen 2001 ilm_labelspace 0 nhlfe_key 0x3
    ip route add 10.0.0.1/32 via 192.168.0.1

Let me know how this works for you.

On Thu, Mar 09, 2006 at 03:35:35PM +0200, Irina Dumitrascu wrote:
> hello,
> i've run the tests with 2 LERs and one LSR and I've observed that the TTL=
 is
> decremented on the MPLS link, but it is disregarded in the Egress router,=
so
> the IP packet leaves with the TTL it had when it entered the MPLS
> network.(the MPLS network is seen like one hop).
> How can i change the TTL in the MPLS Egress node?(so that the TTL from MP=
LS
> packets is copied in the TTL field of IP packets. )
>=20
> I've tried with the option "no_propagate_ttl" : mpls nhlfe change key 0x3
> no_propagate_ttl, but i've observed that at the LER ,it doesn't copy the =
TTL
> field from the IP packet and the MPLS packets leave with the TTL=3D255.
>=20
>=20
>=20
> PS: i've used your advice with the exemple with 2 LERs and 1 LSR and it
> works.
> Thank you very much

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