i'm interrupting here. i've never dealt with MPLS before.
but what i understand is every gateway router passed along will reduce TTL inside packet by 1. else stale packet will never age and will never get removed. imagine packets from the original 1970s network still bouncing around because TTL never reach 0.
it make sense that a packet outside whatever-kind-of-tunnel will get TTL reduced as it hops by each gateway router.
it also makes sense for a packet inside whatever-kind-of-tunnel get not get modified by MITM gateway routers in-between, but only by the ingress and egress devices of that the tunnel.
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website is generally at application leyer. OSI 7.
unless the webserver is built ground up to access and retrieve the test packets all the way from layer 3 where TTL is, it is correct to assume that whatever hop information is unreliable and at best only a guess. plus, on an IP network, back-to-back packets don't have to travel on same route to same destination. you can see the effect by repeating traceroutes again and again to distant targets.
QUOTE(kwss @ Jun 21 2024, 01:27 AM)
What do you mean? TTL is a required headers for all packets, regardless of it's TCP, UDP or ICMP.
There's no such thing as main gateway as every router along the path is technically a gateway. But not all of them will reduce the TTL by 1, in the case of MPLS.
Now there's no way for the web site to know how the packet route at all, including if it went through a tunnel.
Is there a gateway that don't run IP? I am not sure what do you mean.
Is that a question or a statement? Every gateway process TTL. Every gateway runs IP.
QUOTE(nonamer @ Jun 21 2024, 07:56 AM)
if telco does not show mpls routing, do u think ttl is enabled in their mpls network?
This post has been edited by Oltromen Ripot: Jun 21 2024, 11:41 AM