RE: RE: MPLS ping vs normal Ping

mpls ip propagate-ttl

To set the time-to-live (TTL) value on output when IP packets are being encapsulated in MPLS, use the mpls ip propagate-ttl privileged EXEC command. Use the no form of the command to disable this feature.

mpls ip propagate-ttl

no mpls ip propagate-ttl

The mpls ip propagate-ttl command causes a traceroute command to show all the hops traversed by the MPLS packet in the network.

The no form of the mpls ip propagate-ttl command causes a traceroute command to ignore all hops traversed by the MPLS packet in the network.

-----Original Message-----
From: Roger Clark Williams [mailto:rogerw@nordlink.com]
Sent: Friday, March 28, 2003 8:33 AM
To: MPLS-ops Mailing List
Subject: Fwd: RE: [MPLS-OPS]: MPLS ping vs normal Ping

Mourad, these are the IOS commands you may need:

tag-switching ip propagate-ttl

mpls ip propagate-ttl

It is my understanding the translation works like this:

Normally, the IP TTL is copied (with 1 step decrement) into the MPLS TTL. Across the MPLS network the MPLS TTL will be decremented at each hop, and it will overwrite the IP TTL at the egress.

If you use either of these commands, the IP TTL is not copied into the MPLS TTL field. Instead, the MPLS TTL will be written as 255, and decremented across the MPLS network. In cell mode, (no TTL in ATM cells) the total number of hops will be decremented at the beginning of the ingress, and only if there is at least a positive 1 hop will the cell be sent across the ATM portion of the network.

I hope this helps

Roger Williams

Resent-Date: Fri, 28 Mar 2003 05:23:25 -0500
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From: Mourad BERKANE <mourad.berkane@lambdanet.fr>
To: "'R V'" <rvb17@hotmail.com>
Cc: mpls-ops@mplsrc.com
Subject: RE: [MPLS-OPS]: MPLS ping vs normal Ping
Date: Fri, 28 Mar 2003 11:06:45 +0100
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IP TTL is generally map to MPLS TTL but you could hopefully disable it and avoid ICMP message each time you cross a LSR.

For more infos, please refer to following draft (ICMP Extensions for MultiProtocol Label Switching)

draft-bonica-icmp-mpls-0x.txt

Regards,
Mourad

-----Message d'origine-----
De : R V [mailto:rvb17@hotmail.com]
Envoyé : jeudi 27 mars 2003 18:38
À : mpls-ops@mplsrc.com
Objet : [MPLS-OPS]: MPLS ping vs normal Ping

does anybody know how ping implementation for MPLS doman is different from
ping in IP domain?

Regards
RV

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RE: RE: MPLS ping vs normal Ping

mpls ip propagate-ttl