Traceroute includes un-routable IP (?)

Solution 1:

RFC1918 addresses (10/8, 172.16/12 and 192.168/16) should not appear in global routing tables, as they're designed to be used within "a single enterprise". However, it makes sense, to some extent, using RFC1918 addresses for your point-to-point links within your core, even if the traffic going across those links are for "globally routable" IP address ranges, as this conserves a slightly scarce resource.

The reason it shows up in the traceroute is that the TTL of an IP frame expired on an interface with that as its interface IP. The down-side of doing this is that it gets harder to ping the interface and do some troubleshooting on the issue, but there is no guarantee that you should be able to do that anyway.

So, I'd say that it may be a bit unusual, but it's certainly not unheard of.

Solution 2:

That does seem odd to me. It is perfectly okay too see private IPs in the middle of a route, because a single organization can use a private IP within their network. But according to whois, 212.143.14.154 and 195.66.225.105 are owned by two different organizations. But maybe these two orginizations have a point to point between each other, in which case the could use a private IP for it.

The term non routable is not entirely accurate, because they can be routed. However, the should only be used by a single 'enterprise', the term RFC1918 uses. Which is why I find this a bit odd.