Re: Strange public traceroutes return private RFC1918 addresses

[Vincent Gillet - Opentransit <vgi () zoreil com>]

matthew () crocker com disait :

> Search the archives,  Comcast and other cable/DSL providers use the 
> 10/8 for their infrastructure.  The Internet itself doesn't need to be 
> Internet routable.  Only the edges need to be routable. It is common 
> practice to use RFC1918 address space inside the network. Companies 
> like Sprint and Verio use 'real' IPs but don't announce them to their 
> peers on customer edge routes.

Are you sure about Sprint ?

I was told that Sprint DOES announce edge blocks to peers/custom (For URPF
i guess) but blackholes this block at the edge.

Thus you can still traceroute the IP up to Sprint edge, but cannot get
into Sprint network.

This is a hot issue for Opentransit since we are considering not
announcing some infrastructure blocks.

I think that Sprint way is rather smart :

. It prevent/mitigate infrastructure DDOS
. It keeps working with URPF enable peers.

Vincent, Opentransit - France Telecom