08-06-2019 07:15 AM
Hello!
I work for a mid-sized ISP and we have an MPLS core consisting of ASR9K, ASR903, and ASR920 devices. We use OSPF and LDP. Currently, we have a VRF for internet traffic, which uses a L3VPN and BGP to get around our network. Our edge connections are also in a VRF using the same principles. This works great, however, customers are seeing default table hops in their traceroutes to the internet through our L3VPNs. I would like to know if there is a way to limit this visibility to hops in the VRF. I found some useful info on TTL propagation, but it seems that the "no mpls propogate-ttl" command is unavailable on our ASR900 devices. We are running 16.9.3 currently. Is this the correct command to fix this issue? If not, does anyone know a workaround? Thank you in advance for your help!
Solved! Go to Solution.
08-06-2019 07:34 AM
Hello Matt,
your understanding is correct
the command
no mpls propagate-ttl
is the right tool to avoid to expose ISP router hops in global routing table to the customers when they perform a traceroute.
It is strange that ASR 900 does not support it.
Hope to help
Giuseppe
08-06-2019 07:34 AM
Hello Matt,
your understanding is correct
the command
no mpls propagate-ttl
is the right tool to avoid to expose ISP router hops in global routing table to the customers when they perform a traceroute.
It is strange that ASR 900 does not support it.
Hope to help
Giuseppe
08-06-2019 09:37 AM
Upon further inspection, the command on the ASR900 devices with 16.X is:
no mpls ip propagate-ttl
The IP got me....yet again...
Thank you very much for the reply! Your response caused me to look deeper to find the solution!
08-06-2019 06:26 PM
08-10-2019 07:16 PM - edited 08-10-2019 07:17 PM
Hi Matt,
The commands are:
IOS/IOS-XE - "no mpls ip ttl-propagate"
IOS-XR - "mpls ip ttl-propagate disable"
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